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Development of Sand-Bedded Rivers in Glaciated Southern Ontario
By
Anna Marie Megens
A thesis submitted in conformity with the requirements
for the degree of Master of Science
Graduate Department of Geography
The University of Toronto
© Copyright by Anna Marie Megens, 2015
ii
Development of Sand-Bedded Meandering Rivers in Glaciated Southern Ontario
Anna Marie Megens
Master of Science, 2015
Department of Geography, The University of Toronto
Abstract
Many studies of river floodplain sedimentology demonstrate a need to simplify
observations in the form of standard floodplain models. A field investigation was undertaken to
test the applicability of the accepted sand-bedded river facies model provided by Miall (2010), to
sand-bed rivers in southern Ontario. A challenge in this environment is the influence of non-
alluvial channel boundary materials such as glacial outwash sands, till, and glaciolacustrine clay.
The presence of these materials in some channel beds and banks suggest that recognized
“models” may not always be appropriate at predicting channel behaviour. A multifaceted
approach (sedimentology, channel surveys, geophysics, etc.) is used to characterize the processes
controlling the lateral and vertical mobility of these active sand bed channels. This study
proposes that three primary fluvial process domains can be identified and used to explain
variable floodplain and channel morphologies, based on slope, migration patterns,
sedimentology, and proximity to glacial landforms.
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Acknowledgements
Throughout the course of this thesis, I have had insurmountable support from my family
and friends. I would first like to thank my adviser, Dr. Joe Desloges for generously funding this
project and allowing me to explore several rivers throughout southern Ontario; I have learned so
much about this beautiful province. I would also like to thank my committee members, Dr. Sarah
Finkelstein and Dr. Trevor Porter for providing me with the opportunity to share my research
with them. Their comments and suggestions have greatly improved the final version of this
thesis.
I would like to thank my colleagues Dr. Roger Phillips, Kristina Bijeikaite, Tina Hui, and
April Sue Dalton. Roger was a great resource to me throughout the past two years, he offered
feedback, support, and career guidance. I would also like to thank Tina and April for their help in
the lab and Kristina, my field assistant. This thesis wouldn’t have come to fruition without
Kristina, no matter the task at hand, she was always up for it. Moreover, Kristina’s independent
study with Dr. Joe Desloges was a great contribution to this project. I would also like to extend
thanks to all of the landowners, whom kindly permitted access to their land for research
purposes.
Finally, I would like to thank my parents and fiancé Brad Soleski and his family, they
have shown unconditional support and have allowed me to fully engage myself into my work by
relieving the financial burden that often accompanies a Master’s education.
iv
Contents Chapter 1: Introduction ............................................................................................................................. 1
1.1 Definition of the Problem .............................................................................................................. 1
1.2 Research Objectives ...................................................................................................................... 3
Chapter 2: Literature Review .................................................................................................................... 4
2.1 Floodplain Classification of Alluvial Rivers ....................................................................................... 4
2.2 Downstream Channel Characterization ........................................................................................... 10
2.3 Longitudinal Profiles ........................................................................................................................ 14
2.4 Description and Interpretation of Alluvial Deposits ......................................................................... 16
2.5 Controls on Floodplain Formation and Alluvial Deposition ............................................................ 21
2.6 Early Models of Meandering River Floodplains and Channel Change ........................................... 25
2.8 Meandering River Floodplains in Canada ....................................................................................... 30
2.8 Research Questions ........................................................................................................................... 32
Chapter 3: Study Area .............................................................................................................................. 33
3.1 Hydrology ......................................................................................................................................... 33
3.2 Geology ............................................................................................................................................. 36
3.3 Physiography .................................................................................................................................... 38
Chapter 4: Methods .................................................................................................................................. 43
4.1 Slope, Cross-Sectional Geometry, Drainage Area and Discharge ................................................... 43
4.3 Sedimentary Structures and Grain Size Analysis .............................................................................. 44
4.3 GPR Analysis Methods ..................................................................................................................... 47
Chapter 5: Results ..................................................................................................................................... 49
5.1 Introduction....................................................................................................................................... 49
5.2 High Energy, Upper-Watershed Reaches ......................................................................................... 56
5.3 Medium Energy, Middle-Watershed Reaches ................................................................................... 68
5.4 Low Energy, Lower-Watershed Reaches .......................................................................................... 80
5.5 The Role of Glacial Conditioning ..................................................................................................... 92
5.6 Rates of Lateral and Vertical Accretion in the Norfolk Sand Plains ................................................ 98
Chapter 6: Discussion and Conclusion.................................................................................................. 101
6.1 Introduction..................................................................................................................................... 101
6.2 Summary ......................................................................................................................................... 102
References ................................................................................................................................................ 109
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List of Figures
2.1 - Hjülstrom diagram………………………………………………………………… 5
2.2 - Classification of river planforms………………………………………………….. 11
2.3 - Slope-area plots plotted with specific stream power curves……………………….. 13
2.4 - Point-bar depositional model……………………………………………………... 23
2.5 - Block diagram of a meandering sand-bedded river……………………………... 26
3.1 - Five study watersheds chosen to test the sand-bedded meandering facies model…. 35
3.2 - Flood frequencies …………………………………………….................................. 36
3.3 - Physiography of southern Ontario ………………………………………………… 39
3.4 - Physiographic regions of southern Ontario, in the area of the five study watershed. 40
5.1 - Common seismic reflection patterns observed from GPR reflection surveys …….. 54
5.2 - Discrimination between stable sand-bedded meandering river reaches and
unstable gravel-bed river reaches…………………………………………………... 57
5.3 - Specific stream power-drainage area analysis plotted for 9 studied river reaches in
southern Ontario……………………………………………………………………. 58
5.4 - High-energy, upper-watershed meandering river reaches ………………………… 60
5.5 - Big Creek site 101 Sedlog………………………………………………………….. 61
5.6 - Kettle Creek site 401 Sedlog ………………………………………………………. 62
5.7 - Catfish Creek site 301, photographic evidence of silt hardpan and gravel………… 63
5.8 - Map of surveys conducted at Kettle Creek site 401 ……………………………….. 64
5.9 - GPR reflection survey collected at Kettle Creek site 401………………………….. 66
5.10 - GPR reflection survey collected at Kettle Creek site 401………………………… 67
5.11 - Medium energy, middle-watershed meandering river reaches…………………… 70
5.12 - Big Otter Creek site 202 Sedlog, Step 1 of 4……………………………………... 71
5.13 - Big Otter Creek site 202 Sedlog, Step 2 of 4……………………………………... 72
5.14 - Big Otter Creek site 202 Sedlog, Step 3 of 4……………………………………... 73
5.15 - Big Otter Creek site 202 Sedlog, Step 4 of 4……………………………………... 74
5.16 - Ausable River site 504 Sedlog……………………………………………………. 76
5. 17 - Map of the surveys conducted at Big Otter Creek site 202……………………… 77
5.18 - GPR reflection survey collected at Big Otter Creek site 202…………………….. 78
5.19 - GPR reflection survey collected at Big Otter Creek site 202…………………….. 79
5.20 - Medium energy, lower watershed reaches………………………………………... 81
5.21 - Catfish Creek site 302 Cut-bank Sedlog………………………………………….. 84
5.22 - Catfish Creek site 202 Soil Core Sedlog………………………………………….. 85
5.23 - Map of the surveys conducted at Big Otter Creek site 203 and Catfish Creek site
302………………………………………………………………………………… 86
5.24 - GPR reflection survey collected from Big Otter Creek site 203, apex…………… 88
5.25 - GPR reflection survey collected from Big Otter Creek site 202, downstream…… 89
5.26 - GPR reflection survey collected from Catfish Creek site 302, upstream………… 90
5.27 - GPR reflection survey collected from Catfish Creek site 302, apex……………... 91
5.28 - Slope area analysis for 9 river reaches in southern Ontario………………………. 94
5.29 - Big Creek longitudinal profile …………………………………………………… 95
vi
5.30 - Big Otter Creek longitudinal profile……………………………………………… 96
5.31 - Catfish Creek longitudinal profile………………………………………………… 96
5.32 - Kettle Creek longitudinal profile ………………………………………………… 97
5.33 - Ausable River longitudinal profile ……………………………………………….. 97
5.34 - Lateral migration of Big Otter Creek 1909-present………………………………. 98
5.35 - Lateral migration rates observed on Big Otter Creek ……………………………. 99
List of Tables
2.1 - Lithofacies common to alluvial depositional environment………………………… 18
2.2 - Within-channel architectural elements……………………………………………... 20
2.3 - Architectural elements of the overbank environment……………………………… 20
3.1 - Drainage area and bankfull discharges for each respective study reach and gauge
station………………………………………………………………………………. 34
5.1 - Bankfull channel and floodplain characteristics…………………………………… 51
5.2 - Description of meandering channel floodplain types for sand-bedded rivers in
southern Ontario……………………………………………………………………. 52
5.3 - Common of lithofacies observed in studied river reaches of southern Ontario……. 53
5.4 - Description and interpretation of radar facies common to sand-bedded meandering
rivers in southern Ontario ………………………………………………………….. 55
List of Equations
2.1 - Lane’s relation…………………………………………………………………….... 6
2.2 - Leopold and Wolman meandering-braiding threshold slope……………………..... 7
2.3 - Stream power……………………………………………………………………..... 8
2.4 - Specific stream power…………………………………………………………….... 8
2.5 - Discharge power-law relationship……………………………………..…………... 10
2.6 - Bankfull width power law relationship…………………………………………….. 12
2.7 - Slope-area space and specific stream power.……………………………………..... 12
2.8 - Reflector depth, estimated using dielectric permittivity………………………........ 28
2.9 - Signal velocity, measured using dielectric permittivity……………………………. 28
2.10 - Signal velocity, measured using wavelength and frequency……………………... 29
4.1 - Reach specific bankfull discharge, this study…………………………………..….. 44
4.2 - Reach specific bankfull discharge, Phillips and Desloges (2014)……………..…... 44
4.3 - Reach specific bankfull discharge, Annable (1996)………………………..……… 44
List of Appendices
A. Facies, Lithofacies and Hierarchy of Facies………………………………………… 117
B. Study Reach Characterization……………………………………………………….. 120
C. Grain-Size Analysis………………………………………………………………….. 124
1
Chapter 1: Introduction
1.1 Definition of the Problem
The processes and mechanisms responsible for floodplain development in meandering
river floodplains are well understood. Moreover, the subsurface sedimentary architecture has
also been linked to patterns of sediment erosion and deposition. Many methods have been used
to describe, classify, and interpret fluvial deposits in terms of boundary surfaces, lithofacies,
lithofacies associations (architectural elements), and geometry of sedimentary units (Bridge,
1993). Given that floodplain morphology is very dynamic, there have been several attempts
made to standardize the description, classification, and interpretation of fluvial deposits. One of
the first facies models for sand-bedded rivers was proposed by Miall (1985), and has since then
been revised by Holbrook et al. (2006), Bridge (2009), and Miall (2010).
In the model Miall (2010) defines seven discontinuities that make up the depositional
elements of floodplains. These units are defined by their geometry and their fill and include:
channel fills, lateral accretion elements, downstream macroforms, overbank fines, gravity flows,
sandy bedforms, and laminated sand sheets. Holbrook et al. (2006) modified Miall’s original
model to emphasize the ridge and swale topography, natural levees, and the tendency for
channels to cut or avulse to a more favourable course. Accretionary style of point-bar
development is also defined by Miall (1992, 2010). The model demonstrates laterally accreting
deposits dipping toward the apex of the meander bend, with sediments sorted under conditions of
decreasing depth and velocity accounting for the decrease in grain size and scale of
hydrodynamic structures.
2
Coarse grained meandering rivers (sand and/or gravel) are characterized by point-bar
deposits, which typically have a lag deposit at their base and are capped by fine grained
floodplain deposits accumulated through vertical accretion. This model is the basis for the classic
fining upward sequence in meandering sand-bedded rivers (Marriott et al., 2005). However, in
low-relief glacially conditioned catchments of southern Ontario the assemblage of architectural
elements and accretionary style are not well known. Sand-bedded meandering rivers of southern
Ontario require a comparison to the “standard” model to demonstrate the spatial relationships
between channel morphologies in the context of glacial legacy effects.
Phillips and Desloges (2014) model of glacially conditioned specific stream power in
Southern Ontario demonstrates that river reaches can be classified by glacial landform type. It
was shown that over-steepened and under-steepened slopes were strongly associated with the
position of glacial landforms, including sand and clay plains, till plains, and glacial moraines.
Downstream specific stream powers were dictated by the relative location of glacial landforms
throughout the reach. Moreover, Thayer (2012) points to longitudinal profiles composed of both
convexities and concavities linked to slopes controlled by glacial features. In his research
(Thayer, 2012) the channel slope and downstream specific stream powers were strongly affected
by the presence of the Oak Ridges Moraine.
In this study, the 5 studied watersheds are composed of a complex assemblage of glacial
landforms specifically the Mount Elgin Ridges, Ekfrid Clay Plains and the Norfolk Sandplains.
Several till plains are also observed as outcrops in the studied watersheds (Barnett, 1982). These
non-alluvial boundaries may significantly affect channel slope in addition to erosional and
depositional processes making up the floodplain. The key differences between these floodplains
is their transition from locations in the steep morainic ridges of the watershed headwaters, to
3
much lower stream powers of the outlet glaciolacustrine plains. Most of the models discussed in
the literature are from environments whereby Pleistocene sediments have been eroded and
redeposited into the modern floodplains. However, floodplain development in areas where
Holocene fluvial sediments are bound by Pleistocene deposits is less well understood. The effect
these boundary materials have on channel morphology and adjacent floodplain is largely absent
from discussions in the literature.
1.2 Research Objectives
The research presented here aims to fulfill the following research objectives:
(1) Characterize the mechanisms that control channel and floodplain developments in
sand-bedded rivers of southern Ontario;
(2) Consider the role of glacial conditioning;
(3) Determine rates of vertical and lateral accretion; and
(4) Compare the results against the “standard” facies model of sand-bedded meandering
rivers.
4
Chapter 2: Literature Review
2.1 Floodplain Classification of Alluvial Rivers
For the purpose of this study, floodplains are categorized genetically because of the
strong connection between river processes and the floodplains they develop. Alluvial floodplains
are defined as the horizontally-bedded alluvial landform adjacent to the active channel, built up
by sediments transported by the current flow regime (Nanson and Croke, 1992). The three classic
channel river planforms that lead to the establishment of floodplains are straight, meandering,
and braided (Schumm, 1981). These planforms are also recognized as end members in a
continuum of planform change in alluvial rivers (van den Berg, 1995). The discrimination
between channel planforms begins with sediment transport regimes and the competence and
capacity of a river to transport sediment of a given grain-size (Church, 2006).
The relationship between flow strength and particle entrainment of a given grain-size can
most easily be described using the Hjülstrom curve (Figure 2.1), which demonstrates the velocity
required to entrain and transport sediment. The upper curve shows the velocity required to
entrain a particle from a resting position, while the lower curve demonstrates the relationship
between flow velocity and grains already in motion. These two lines are parallel to one another
for particle sizes above 1 mm – the upper grain-size limit for sandy materials. Particle sizes finer
than coarse silt however, require greater velocities to initiate motion. This is mainly due to the
cohesive clay-rich minerals that bind together once deposited, making them behave as if they
were sand-sized particles (Nichols, 2009).
It is important to discuss the relationship between flow strength and particle entrainment
because the classification of rivers is based on the capacity to move sediment of a specific caliber
5
given the right conditions of slope and discharge. In glacially conditioned catchments,
measurements of slope and discharge alone may not be adequate, as slopes may be controlled by
glacial legacy effects. By reviewing the energy required to move sediment of a specific size one
can determine whether or not a river reach is capable of entraining and transporting sediment
derived from glacial deposits that form some channel boundaries.
Figure 2.1 - The Hjülstrom diagram demonstrating the threshold velocities of flow required to
entrain, move and deposit sediment of any given size. Reprinted with permission
from Nichols, G. 2009. Sedimentology and Stratigraphy, 2nd Edition. John Wiley and
Sons Ltd., West Sussex, UK, p. 48.
6
The balance between a stream`s power and sediment transport/yield goes back to the
origin of Lane’s (1955) relation with the following expression (equation 2.1) relating discharge
(Qw) and channel slope (S) to sediment discharge or load (Qs), and a representative bed material
size (Dx) for a given river under equilibrium conditions:
QwS QsDx (2.1)
An imbalance between these conditions governs the propensity for aggradation or degradation
and the style and rate of lateral river channel movement (Church, 2006). Consequently, the
mechanisms by which rivers respond to environmental changes and maintain equilibrium have
been adopted to address complex river responses and adjustments to channel planform (Dust and
Wohl, 2012). It has been suggested by several authors (Brunsden and Thornes, 1979; Schumm,
1981; van den Berg, 1995) that thresholds exist between the three classic channel patterns and it
is understood that if a threshold should be crossed, a river would potentially respond rapidly and
adjust to a new equilibrium and channel pattern (van den Berg, 1995). In some cases, crossing a
threshold may be perpetuated by channel/floodplain confinement, bank stabilization, and
redistribution of flow. For example, the targeted channel pattern for specific reaches within
Highland Creek, ON, shifted during an extreme flood event in 2005. Due to increasing urban
pressures in the Highland Creek watershed, maximum stream powers exceeded the capacity of
the river to maintain a meandering planform, consequently reaches that were unable to cope with
the increased magnitude of discharge and newly created sediment size, adopted a more braided
planform by widening and straightening their boundaries (Ferencevic and Ashmore, 2005).
Changes in the trajectory of channel planform may occur in the natural environment as
well, irrespective of anthropogenic influence. However, the thresholds between alternate
planform types may not be as discrete as once understood, and channel change may be more
7
gradual rather than rapid (van den Berg, 1995). For example: gradual transitions between
planform types may be explained using channel migration rates. Since migration rates are
expected to increase with increasing stream power (Hickin and Nanson, 1988), the accelerated
migration promoted by a series of moderate flood events (e.g. 2-10 year recurrence interval) may
act as a catalyst for avulsion and scour of a secondary channel during a high magnitude flood. As
a result, highly sinuous meandering channels may form meander cut-offs during high stage flow
events and adopt a planform with a lower sinuosity and a higher gradient in natural environments
(Wallick et al., 2007).
The discrimination between the three classic end members planforms - straight from
meandering and meandering from braided - is often described using a set of different functions
involving slope and discharge. One of the most widely used discriminating functions was
proposed by Leopold and Wolman (1957) as:
S* = 0.0125Q-0.44 (2.2)
where Q is the bankfull discharge and S* is the meandering-braiding threshold slope (Phillips and
Desloges, 2014). Today the Leopold and Wolman (1957) function is used as a line of
discrimination between braided and meandering planforms. However, because this
discrimination line does not have predictive value, due to the fact that channel slope is a function
of channel sinuosity (van den Berg, 1995) and that the transition criterion for braiding is also a
function of grain-size, the function may alternatively be better used to discriminate between
laterally stable (single-thread) and laterally unstable (multi-channel) planforms.
As discharge and slope are components of stream power, the evaluation of stream power
is also a useful predictor of boundary erosion and channel migration, sediment transport,
sediment deposition and bedform type (Nanson and Croke, 1992). Using the reasoning that
8
stream power is diagnostic of flow and sediment properties, an energy based floodplain
classification scheme was developed by Nanson and Croke (1992) to employ an erosive
power/resistance concept. This concept is most easily defined using total stream power (Eq. 2.3),
where river planforms fall along a total stream power (𝛺) energy continuum, where total stream
power is:
𝛺 = 𝛾𝑄𝑆 (2.3)
and γ is the specific weight of water, Q is the discharge and S is the slope. Power per unit area of
the bed is diagnostic of the potential energy available to erode and construct individual
landforms (Knighton, 1999; Walker et al., 1997). The rate at which this energy is supplied to the
bed is expressed by specific stream power and is summarized as:
𝜔 =𝛺
𝑊 (2.4)
where w is average bankfull width.
Specific stream power provides an opportunity to compare rivers of different sizes, and
their associated floodplains by evaluating the potential energy available to do work in each
system (Nanson and Croke, 1992). The energy-based floodplain classification scheme recognizes
three energy zones, whereby lower streams power are associated with floodplains that have fine-
grained channel boundaries, and higher stream powers are associated with floodplains with
coarse-grained channel boundaries. The caliber of the sediment load, thus determines the
sediment composition of the floodplain, which in turn strongly influences the resistance of the
stream banks to erosion.
The energy zones and the character of the sediment load carried within the flow were
integrated by Nanson and Croke (1992) to define three primary floodplain classification groups.
The first two groups are largely comprised of non-cohesive alluvium (gravel to fine sand) and
9
those of cohesive alluvium (silt and clay). The non-cohesive floodplains have two energy
environments, high and medium, which are based on sediment size and a characteristic
entrainment threshold. High-energy non-cohesive floodplains are recognized to be in a state of
disequilibrium. Bankfull specific stream powers greater than 300 W m-2 are expected due to their
location within steep upland areas, where channel bed macroforms (e.g. bars) erode completely
or partially due to infrequent extreme events or a series of moderate events. Vertical accretion
deposits on the channel banks and floodplains dominate in these high-energy floodplains as
lateral migration is prevented due to very resistant coarse alluvium or bedrock boundaries
(Nanson and Croke, 1992). Medium-energy non-cohesive floodplains have bankfull specific
stream powers between 10 and 300 W m-2. These floodplains are considered to be in a state of
dynamic equilibrium within an annual to decadal flow regime and are rarely affected by extreme
events. Specific stream powers are kept low because energy is dispersed across the floodplain
when discharges overtop the bank. Lateral point-bar accretion or braid-channel accretion are the
dominant mechanism of floodplain construction in these medium energy non-cohesive
floodplains (Nanson and Croke, 1992).
Low-energy, cohesive, floodplains are dominated by silt and clay banks, with bankfull
specific stream powers < 10 W m-2. They are usually associated with laterally stable, single-
thread, or anastomosing channels. Low stream power is primarily a function of wider channels
and low gradients, allowing for water to easily spill onto the floodplain, dissipating erosional
energy. Rapid lateral migration is inhibited due to the high bank resistance imposed by fine-
grained cohesive materials. As a result, low-energy floodplains are formed predominantly by
vertical accretion and infrequent channel avulsion (Nanson and Croke, 1992).
10
Nanson and Knighton (1996) expanded upon the energy-based floodplain classification
and defined four primary channel types and subtypes based on their singular or multiple channel
planforms, lateral activity, and rate of energy expenditure per unit area of the channel bed. This
updated classification scheme, reproduced in Figure 2.2, discriminates between single-thread and
anabranching channels, which are defined as systems with multiple vegetated islands divided by
stable channels at bankfull flow. Using Nanson and Knighton’s (1996) classification scheme, end
members from high to low energy expenditure are defined, with lateral activity increasing with
energy expenditure. This presents a very interesting comparison between the two classification
schemes by Nanson and Croke (1992) and Nanson and Knighton (1996). Each is influenced by
energy expenditure, but grain-size has been excluded in the latter; replaced by lateral activity,
suggesting that lateral activity increases with increasing grain size, or more specifically less
cohesion in the banks.
2.2 Downstream Channel Characterization
Discharge and bankfull width regime models are used in conjunction with specific stream
power to help explain variability in the downstream hydraulic geometry. Establishing a
hydrologic geometry for a class of river types, such as meandering sand-bedded rivers, can be
very useful in determining how width, depth, and velocity of flow are most likely to vary in
successive downstream cross-sections (Ferguson, 1986; Dingman 2007). In watersheds where
there are infrequent or no gauging stations, downstream discharge can be estimated using well
behaved, regionally-derived power-law relationships between drainage area and bankfull
discharge, defined as:
𝑄 = 𝛼𝐴𝑑𝛽
(2.5)
11
where Ad is the drainage area (km2) at any given point in the downstream direction and the
coefficient α and exponent β are estimated using statistical regression of empirical data.
Figure 2.2 - Classification of river planform for single and anabranching channels, using the rate
of energy expenditure and lateral mobility as discriminating terms. Reprinted with
permission from Nanson, G.C., and Knighton, A.D. 1996. Anabranching rivers:
theirs cause, character, and classification. Earth Surface Processes and Landforms,
21(3), p. 236.
12
Since Q is the product of w x d x v, downstream bankfull channel widths (w) may also be
estimated using a power-law relationship with drainage area (Ad):
𝑤 = 𝑎𝐴𝑑𝑏 (2.6)
where the coefficient 𝑎 and exponent b are also estimated by empirical regression (Phillips and
Desloges, 2014). For the mapping of specific stream power is southern Ontario, Phillips and
Desloges (2014) used these statistically calibrated regime models to establish fluvial process
domains under slope-area analysis. By combining the equation for specific stream power (Eq.
2.4), with Eq. 2.5 and Eq. 2.6 above, a suit of curves were developed within the slope-area space
for the region of southern Ontario (Figure 2.3).
The concept suggests that specific channel forms may be divided regionally and reflect
different channel responses (Montgomery, 1999). In southern Ontario, a stream power threshold
of the type in the following equation can be used to frame the dominant river and floodplain
types into slope-area space:
𝑆 = 𝜔
2100𝐴𝑑
−0.4 (2.7)
where specific stream powers (ω) define the relevant ranges for each river type within a specific
type of boundary condition (also known as process domains; Brardinoni and Hassan 2006).
Different glacial landforms/materials include till and kame moraines, outwash plains, till plains,
glaciolacustrine sand plains, and glaciolacustrine clay plains (Phillips and Desloges, 2014).
13
Figure 2.3 – Slope-area plots and stream power curves based on Eq. 2.7 for 246 river reaches in
southern Ontario. This plot provides a comparison of reaches classified by glacial
landform type. Reprinted with permission from Phillips, R.T.J. and Desloges, J.R.
2014. Glacially conditioned specific stream powers in low-relief catchments of the
southern Laurentian Great Lakes. Geomorphology, 206, p. 284.
The result of the slope-area analysis for southern Ontario is the recognition of the glacial
conditioning of rivers greater than 100 km2. It was found that reaches flowing through moraines,
many of them confined, consistently plot above ~30 W m-2 with many river reaches ranging
between 60 and 100 W m-2. Entrenched rivers caused by lake level adjustments or tributary
incision also plot above 30 W m-2, with averages greater than 60 W m-2; whereas till and
glaciolacustrine plains tend to plot below 30 W m-2, with many also plotting below 10 W m-2
(Phillips and Desloges, 2014).
14
2.3 Longitudinal Profiles
An elevation (longitudinal) profile is a particularly useful approach for providing insight
to channel pattern responses governed by climatic, geologic and glacial controls on channel slope
(Brunsden and Thorne, 1979; Addy et al., 2014). Together, these controls define the driving
mechanisms of fluvial geomorphic activity, including progradation of the longitudinal profile,
abrasion of the bed, aggradation/degradation of the longitudinal profile balancing subsidence,
and tributary contributions to total discharge and sediment load (Sinha and Parker, 1996). More
importantly, the profiles represent spatial variations in channel slope and thus the propensity of a
channel to be stable (lower gradient) or potentially unstable (higher gradient).
Longitudinal profiles formed under conditions of dynamic equilibrium are theoretically
expected to reflect a smooth concave-up profile throughout its entire length, with the assumption
that it can be represented mathematically as an exponential curve (Phillips and Desloges, 2014).
This geometric manifestation is commonly known as the graded river profile (Mackin 1948), and
is used as a benchmark from which subtle anomalies may be observed in natural fluvial systems
(Phillips and Desloges, 2014). Parts of the longitudinal profiles may be altered through
aggradation and degradation following changes in sediment supply and size, rapid changes in
discharge and tributary junctions (Henshaw, 2013), sediment transport rate, and degree of
sediment sorting (Sinha and Parker, 1996; Phillips and Desloges, 2014). Due to the exponential
form of the graded profile, stream power is expected to decrease in response to the systematic
downstream increase in discharge and decrease in channel slope (and sediment size).
Consequently, changes to a longitudinal profile’s degree of concavity will have an influence on
the position of maximum stream power throughout the system and thus the character of the
channel and floodplain development (Knighton, 1999).
15
Based on the graded river profile as interpreted by Schumm (1977) and reproduced by
Robert (2003), variation in the longitudinal profile can be divided into three predominant zones:
the source/protection zone, the transport zone, and the deposition zone. Typically hillslope-
channel coupling is extensive in the steeper headwater reaches or production zone of a river
basin, characterized by coarse grain-sizes and channel anabranching in regions of high sediment
supply (Thayer, 2012). In piedmont and non-glaciated mountainous environments, step-pool and
cascade morphologies dominated by log and debris jams are also characteristic of the production
zone (Thayer, 2012). With decreasing slope and decreasing capacity to transport sediment, bed
material begins to fine downstream in the deposition zone, which is a significant geomorphic
characteristic of sinuous fluvial systems (Labrecque et al., 2011). Channel width-depth ratios
also decline and the relative volume of stored alluvium increases. This often results in sand-
bedded, sinuous, narrow, and deep channels in the lower reaches of a river longitudinal profile
(Fola and Rennie, 2010).
Where persistent passive disequilibrium prevails, antecedent hydrological and
sedimentological regimes may continue to control floodplain formation processes (Nanson and
Croke, 1992). In southern Ontario, profile irregularities such as knickpoints, knickzones, or other
convex features have been observed by Thayer (2012), Addy et al. (2014) and Phillips and
Desloges (2014). These catchments comprise a complex assemblage of glacial and paraglacial
materials delivered by mass wasting or exposed by fluvial incision (Addy et al., 2014). The
magnitude and position of coarse lag deposits or locally high sediment inputs from paraglacial
stores (e.g. alluvial fans and valley fills) and glaciogenic landforms (e.g. moraines and valley
fills), can influence where certain channel types occur in relation to slope (Addy et al., 2014).
16
Therefore, in addition to the slope-area analysis discussed in Section 2.2, the longitudinal profile
is another way to determine downstream glacial conditioning of channel morphology.
2.4 Description and Interpretation of Alluvial Deposits
As mentioned by Dunne and Aalto (2013) and Miall (1992; 2010) not all planform river
classifications are mutually exclusive to all channel types. The subdivision of river types by
major sedimentary units and landform elements has therefore been quite successful at focusing
research and defining dominant processes of floodplain development. Seminal research into the
characteristic fluvial sedimentology of different river types was undertaken by Allen (1963;
1965), Bridge (1985; 1993; 2009), Bridge et al. (1995), Brierley and Hickin (1992), Hickin
(1974; 1993), Leeder (1993), Miall (1985; 1992), Nanson (1980; 1981; 1986), and Smith (1987).
Both Leeder (1993) and Miall (1992; 2010) were the first to describe the relative scales of
depositional units and provide a classification scheme to clarify and universalize the language of
fluvial deposits observed in the field.
For the analysis of floodplain development in modern rivers, alluvial deposits are divided
into four superimposed scales of strata and sets of strata (stratasets). The stratasets include (1) the
complete channel belt; (2) the formation of channel bars and channel fills, (3) large-scale
inclined strata, formally known as storeys; and deposition of (4) cross-stata or planar-strata
associated with the migration and passage of ripples and dunes (Bridge, 1993; 2009).
Today a standard method to describe and interpret fluvial deposits is facies-analysis,
which involves the observation and classification of lithofacies. Lithofacies is a term used
interchangeably with facies, and is used to discriminate between different sedimentary layers of
primary depositional units (Bridge, 1993). Bedding, grain size, texture, and sedimentary structure
17
are all comparative components within each lithofacies unit (Bridge, 2009; Miall, 2010). The
classified units are illustrated in stratigraphic or sedimentary logs collected from outcrops, cores
and cut-bank field profiles. Table 2.1 below provides a basic summary of common lithofacies
observed in sand-bed meandering rivers. A full set of possible lithofacies defined by Miall
(2010) is also provided in Appendix A.
The development of lithofacies is controlled by depositional processes such as bedload
transport, suspended sediment settling, traction currents and debris flows. Therefore, fluid
turbulence can have a noticeable effect on beds of clastic grains producing similar suites of
lithofacies common to all rivers (Miall, 1992; 2010). As a result, lithofacies can unearth
information about past flow regimes, specifically mean flow velocity, using the size, shape and
grain size of bedforms such as ripples and dunes. The migration of bedforms produces the
sedimentary structures observed in the field. The smallest grains remain in suspension unless the
flow of water comes to a complete stop, as would be the case in a floodplain pond or abandoned
channel (Maill, 1992). The style by which these fine grains accumulate is the basis for observing
sedimentary structures in alluvial deposits and the definition of facies or lithofacies (Miall,
1992).
18
Facies
Code
Facies Sedimentary
Structures
Interpretation
Gcm clast supported massive
gravel
Gravel lag deposit
Gh clast supported, crudely
bedded gravel
horizontal bedding,
imbrication
longitudinal bedforms, lag
deposits, sieve deposits
Gt gravel, stratified trough cross beds minor channel fills
St sand, fine to v. coarse,
may be pebbly
solitary or grouped
trough cross beds
sinuous crested and linguoid
(3-D) (lower flow regime)
Sp sand, fine to v. coarse,
may be pebbly
solitary or grouped
planar cross beds
linguoid, transverse bars,
sand waves (2-D dunes)
(lower flow regime)
Sr sand, v. fine to coarse ripple cross-lamination ripples (lower flower
regime)
Sl sand, v. fine to v.
coarse, may be pebbly
low angle (<15°)
crossbeds
scour fills, humpback or
washed-out dunes,
antidunes
Fl sand, silt, mud massive, of faint
lamination
overbank, abandoned
channel, or waning flood
deposit
Fsm silt, mud massive back-swamp or abandoned
channel deposits
Fm mud, silt massive, desiccation
cracks
overbank, abandoned
channel, drape deposits
Fr mud, silt massive, roots,
bioturbation
root bed, incipient soil
P paleosol carbonate
(calcite, siderite)
pedogenic features;
nodules, filaments
soil with chemical
precipitation
Table 2.1 – Lithofacies common to alluvial depositional environments, summarized from: Miall,
A.D. 2010. Alluvial Deposits. In J.P. Noel and R.W. Dalrymple (Eds.) Facies Models
4. Geological Association of Canada, St. John’s, NL, p. 113.
Preserved sedimentary structures observed in the sediment profile, defined by shape, size
and texture, are assembled to form fluvial architectural elements. Architectural elements are
defined as the components of a complete depositional environment, equivalent in size to a
channel fill, but larger than an individual lithofacies unit (Miall, 2010). Architectural elements
are characterized by distinct facies assemblages, internal geometry, external form, and vertical
profile (Miall, 1992; 2010). Architectural elements are used in the genetic floodplain
19
classification scheme and constitute the foundation of river facies models. The descriptive
classification of architectural elements is described by Miall (2010) to have six primary
components: (1) the lower and upper boundary units - erosional or gradational; planar, irregular,
curved (concave-up or convex-up); (2) external geometry - sheet, lens, wedge, scoop, U-shaped
fill; (3) Scale - thickness, lateral extent, parallel and perpendicular to flow; (4) Lithology -
lithofacies assemblage and vertical succession; (5) Internal geometry - nature and disposition of
internal boundary surfaces; relationship of bedding to external boundary surfaces (parallel,
truncated, onlap, downlap); and (6) Paleocurrent patterns - orientation of flow indicators relative
to internal bounding surfaces and the external form element.
Architectural elements are divided into two main groups: in-channel and overbank. In-
channel depositional elements (summarized in Table 2.2) are defined as depositional units
formed under bankfull flow conditions; whereas overbank depositional elements (summarized in
Table 2.3), are formed when the discharge overtops the main channel under rare or catastrophic
flow conditions. Each element, overbank and in-channel, are defined by their principal facies
assemblage; therefore fine resolution lithofacies classifications are preferred for architectural
element analysis. Moreover, the interpretation of the alluvial deposit is strongly dependent on the
shape, size, and angle of accretionary surfaces.
20
Element Symbol Principal facies
assemblage
Geometry and relationships
Channels CH any combination Concave-up erosional base
Sandy bedforms SB St, Sp, Sh, Sl, Sr,
Se, Ss
Lens, sheet, blanket, wedge, occurs as
channel-fills, crevasse splays, minor
bars
Upstream-accretion
macroform
UA St, Sp, Sh, Sl, Sr,
Se,Ss
Lens, resting on bar remnant or LA/DA
deposit. Accretion surfaces dipping
gently upstream
Lateral-accretion
macroform
LA St, Sp, Sh, Sl, Se,
Ss, less
commonly Gm,
Gt, Gp
Wedge, sheet, lobe; characterized by
internal lateral-accretion 3rd order
surfaces. Accretion surfaces oriented
across channel. Typically downlaps
onto flat basal erosion surfaces
Laminated sand sheet LS Sh, Sl, minor Sp,
Sr
Sheet blanket
Table 2.2 – Within-channel architectural elements, summarized from: Miall, A.D. 2010. Alluvial
Deposits. In J.P. Noel and R.W. Dalrymple (Eds.) Facies Models 4. Geological
Association of Canada, St. John’s, NL, p. 118.
Element Symbol Lithology Geometry Interpretation
Levee LV Fl Wedge up to 10 m thick,
3 km wide
Overbank flooding
Crevasse channel CR St, Sr, Ss Ribbon up to a few
hundred m wide, 5 m
deep, 10 km long
Break in main channel
margin
Crevasse splay CS St, Sr, Fl Lens up to 10 by 10 km
across, 0.1-0.6 m thick
Delta-like progradation
from crevasse channel
into floodplain
Floodplain fines FF Fsm, Fl,
Fm, Fr
Sheet, may be many km
in lateral dimensions, up
to 10s of m thick
Deposits of overbank
sheet flow, floodplain
ponds and swamps
Abandoned
channel
CH(FF) Fsm, Fl,
Fm, Fr
Ribbon comparable in
scale to active channel
Product of chute or neck
cutoff
Table 2.3 – Architectural elements of the overbank environment, summarized from: Miall, A.D.
2010. Alluvial Deposits. In J.P. Noel and R.W. Dalrymple (Eds.) Facies Models 4.
Geological Association of Canada, St. John’s, NL, p. 118.
21
2.5 Controls on Floodplain Formation and Alluvial Deposition
In most sandy fluvial systems, the evolution of in-channel bars are a useful example of
how lithofacies assemblages and sedimentary structures, texture, size and orientation are used to
define architectural elements. Well-developed bars may intensify flow along the margins of the
bend and accelerate bank erosion and bend growth (Dunne and Aalto, 2013). The principal
sedimentation process responsible for bend growth is lateral accretion (Dunne and Aalto, 2013).
Lateral accretion, also known as lateral point-bar accretion (Nanson and Croke (1992) or epsilon
cross-stratification (Allen, 1965; Nichols, 2009), is the deposition of clastic material on the
convex bank of a meander bend. The primary process controlling lateral deposition is secondary
circulation, which is made up of centrifugal forces and pressure gradient forces. Centrifugal
forces derive from water flowing around the bend forcing it into a super-elevated position along
the outer bank, tilting the water surface and directing it laterally across the channel (Robert,
2003). The force acting against the centrifugal force, balancing the lateral flow by driving it
inward over the bed surface, is the pressure gradient force. The intermediate position of these
forces resides in the river thalweg, producing a spiraling motion, or cell of secondary flow
(Robert, 2003).
Sediment removed from the cut-bank is incorporated into the overall sediment load of the
river, large blocks slumped into the river may accumulate in the thalweg to form a lag deposit
(Miall, 1992; Labrecque et al., 2011). Sediment accumulates on the point-bar surface at a rate
comparable to how much erosion takes place on the upstream meander bend (Dunne and Aalto,
2013) and in vertically stacked fining-upward packages (Labrecque et al., 2011). Coarse grained
meandering rivers (sand and/or gravel) are characterized by point-bar deposits that typically have
a lag deposit of pebbles and cobbles at their base. As the energy of the flow decreases on the
22
point-bar surface, material of smaller size falls out of suspension, contributing to the fining-
upward sequence (Robert, 2003; Labrecque et al., 2011). Figure 2.4 is the common facies model
for many meandering sand-bedded rivers. The fining-upward sequence is bracketed to the right
of Figure 2.4
Figure 2.4 also demonstrates the pattern of water flow over the point-bar surface, where
flow is more or less parallel to the strike of the accretionary units (Miall, 1992). Each lateral
accretion surface represents a new period of growth that may occur during peak seasonal runoff
or a flash flood. Periods of low flow are represented by mud drapes, whereas periods of erosion
are represented by low-angle disconformity surfaces, truncating the underlying bed. Cross-
cutting erosional surfaces occur in individual cross-beds, and reflect reactivation surfaces (Miall,
1992). Lateral accretion elements range in thickness from 2 m to 25 m in the thick Athabasca Oil
Sands deposits, AB, Canada (Miall, 2010). Typically, these deposits dip between 3 and 25°
according to Miall (1992), and less than 15° according to Nichols (2009). The dip angle is in the
direction of accretion, perpendicular to the flow direction (Miall, 1992; Woolridge and Hickin,
2005; Nichols 2009).
23
Figure 2.4: Point-bar depositional model. The key characteristics of this model are the laterally
accreting surfaces dipping down toward the apex of the meander bend. Retrieved
from Miall, A.D. 2010. Alluvial Deposits. In J.P. Noel and R.W. Dalrymple (Eds.)
Facies Models 4. Geological Association of Canada, St. John’s, NL, p. 117.
Downstream accretion deposits are another commonly observed alluvial deposit, more
typically observed in anabranched channels and characteristic of mid-channel bars. These bars
are commonly referred to as medial, central or longitudinal bars, and given the right conditions
of flow and sediment size, these bars can be observed in wandering channels and some
meandering rivers, in addition to braided channels. The mid-channel or cross-channel position of
these downstream-accretion surfaces are quite variable, but, bar growth near the center leads to
concentration of flow to the narrower flanking channels (Robert, 2003), accreting sediment on
the upstream face, flank and downstream face (Miall, 1992). Rapid erosion may occur with
rising water levels, creating a chaotic depositional pattern from the filling of chute channels
(Miall, 1992). In shallow coarse grained systems, a slight change in flow depth and loss of
competence to move the coarsest fractions would result in local deposition and the initiation of a
central, longitudinal bar (Robert, 2003). Lithologically, the essential characteristics of a
24
downstream accretion deposit are the several coset beds deposited by bedform migration. These
cosets are oblique to flow, and observed to have dip angles between 20-30° (Halfar, 1998), and
less than 10° (Miall, 1992; Woolridge and Hickin, 2005). A coset is defined as a composite set of
lamina or beds. Lamina are layers of sediment less than 10 mm thick and beds are greater than
10 mm. (Bridge, 1993).
As the channel migrates laterally and downstream within the valley, the top of the point-
bar becomes the edge of the floodplain, therefore the fining-upward sequence expected in
meandering channels is often seen to be capped by over bank fines (Nichols, 2009). Overbank
vertical accretion results from flows that exceed bankfull – typically greater than Q2 floods. It is
the process responsible for the development, deposition, and filling of several architectural
elements, including levees (LV), crevasse channels (CR), and crevasse splays (CS), floodplain
fines (FF) and abandoned channels CH (FF) (Halfar et al. 1998). Overbank vertical accretion has
been shown to be the dominant process along low-gradient single thread channels and
anastomosing channels; this is expected in systems where the stream power is not effective at
eroding the channel bank (Nanson and Croke, 1992). However, vertical accretion also dominates
high-energy channels with sandy floodplains, this is because the floodplain is easily destroyed
and subsequently reconstructed by overbank deposition (Nanson, 1986).
Overbank deposits are composed of fine-grained material deposited onto the land surface
during floods. When flooding occurs, sediment-laden water leaves the channel and is deposited
onto the floodplain via the process of sediment diffusion (Pizzuto, 1987; Gouw, 2007).
Relatively coarse grain-sizes are deposited first near the channel margin, due to increased drag
and gravitational force. Finer material is subsequently deposited as water depth and velocity
decrease with distance from the channel edge (Pizzuto, 1987). Moreover, areas with more dense
25
vegetation may increase the accumulation rate by lowering velocity and trapping material
(Dunne and Aalto, 2013). Typically due to the changes in velocity, depth, and vegetation across
the floodplain, vertically accreted overbank deposits decrease in thickness with distance from the
bank. The greatest accumulation will be at the bank itself, forming a naturally elevated surface
commonly known as a levee (Pizzuto 1987; Nichols, 2009).
2.6 Early Models of Meandering River Floodplains and Channel Change
River planform facies models synthesize complex facies assemblages or architectural
elements into norms and provide an excellent basis for comparison. The foundations for the
meandering river facies model can be found from research written by Allen (1963; 1965), Hickin
(1974), Jackson (1978); Nanson (1980, 1981, 1986), Nanson and Page (1983), Miall (1985,
1992) and Smith (1987). Geophysical techniques including ground penetrating radar and wire-
line logs are commonly applied. Although the field has moved away from the generalized facies
model concept, it remains a principal component of current research strategies, especially those
that would like to determine similarities and differences in floodplain formation processes
(Holbrook et al., 2006; Gouw, 2007; Gouw and Berendsen, 2007).
Holbrook et al. (2006) used the architectural element model to compare depositional units
and their boundary surfaces for the Missouri River Valley. This model defines seven
architectural elements within the sand-bedded meandering floodplain defined by their geometry
and their fill. These units are identified in Figure 2.5 and include: channel fills, lateral accretion
elements, downstream macroforms, overbank fines, gravity flows, sandy bedforms, and
laminated sand sheets. An eighth architectural element is also recognized if you subdivide
26
channel fills into (a) channels measuring 10-100 m wide, and (b) palaeo-channels > 100 m wide
(Miall, 1985; Halfar, 1998).
The ridge and swale topography of this model is indicative of a series of lateral
migration stages and result from a combination of processes including the combined process of
lateral migration and flow separation during a flood, increased deposition in vegetated areas, and
erosion in chute or overflow channels (Holbrook et al., 2006). In this model, sandy components
are accompanied by silt-rich natural levees (Holbrook et al., 2006); while point-bars
demonstrates the classic vertical fining-up trend, a product of lateral accretion and decreasing
shear stress (Allen, 1965), capped by clay-rich overbank fines (Miall, 1992, 2010). Internally,
point-bars normally end on their outer bend against a channel-fill element.
Figure 2.5: Block diagram of a meandering sand-bedded river. Adapted from Holbrook J.,
Kliem, G., Nzewunwah, C., Jobe, Z., and Goble, R. 2006. Surficial Alluvium and
Topography of the Overton Bottoms North Unit, Big Muddy National Fish and
Wildlife Refuge in the Missouri River Valley and its Potential Influence on
Environmental Management. In Jacobson, R,B. (Ed.), Science to Support Adaptive
Habitat Management: Overton Bottoms North Unit, Big Muddy National Fish and
Wild Life Refuge. Scientific Investigations Report 2006-50, U.S. Geological Survey,
Washington, DC, p. 22.
27
The advantage of present-day facies models is that researchers can gain a greater
understanding of how fluvial systems evolve and respond to complex sets of internal (allogenic)
and external (autogenic) controls on the composition, geometry, and arrangement of alluvial
architectural elements (Gouw, 2007). Channel change can occur in response to a range of natural
and anthropogenic events, including floods, base-level, climate, tectonics (Gouw, 2007), logging,
agricultural development, erosion control and other engineering works that modify sediment and
flow regimes (Wallick et al., 2007). The geomorphic response to changes in flow regime, bank
erodibility, or sediment supply is manifested in changes to the river channel’s geometry and
planform. Due to the multiplicity of factors contributing to channel change, disentangling the
cause-effect relationships between geomorphic and anthropogenic drivers can be problematic
(Wallick et al., 2007). It is also important to consider that predicted channel responses are not
unique to specific drivers, instead they display equifinality, suggesting that the same response
can have multiple causes (Wallick et al., 2007).
2.7 Ground Penetrating Radar: Use in Sedimentology
Ground penetrating radar (GPR) is used as a geophysical tool to determine stratigraphic
architecture (Bridge et al., 1995; Bristow and Jol, 2003), sand-body geometry, and correlation
and quantification of sedimentary structures (Bristow and Jol, 2003). In this study, GPR is used
to observe the alluvial architecture and evolution of eight large point-bars in the meandering
rivers of Big Creek, Big Otter Creek, Catfish Creek, Kettle Creek and the Ausable River in
southwestern Ontario. Integrating GPR with bathymetry, sedimentology, and aerial photographs
enables the internal architecture to be linked to the evolution of the meandering point-bar and
28
reveal the sedimentary mechanisms that formed the various architectural elements (Bristow and
Jol, 2003; Woolridge and Hickin, 2005).
GPR is a high resolution sub-surface mapping method that utilizes propagating
electromagnetic (EM) waves that respond to changes in the EM properties of subsurface material
(Annan and Davis, 1997). The velocity of propagating EM waves controls the generation of
radar reflections which are determined by the difference in relative permittivity between
background material and the target (Baker et al., 2007). Relative permittivity, commonly known
as a material’s dielectric constant, is a ratio between a material’s dielectric permittivity and the
permittivity vacuum of free space (Beres and Haeni, 1991). It also defines a material’s ability to
store and permit the passage of EM radiation when an electrical field is imposed (Baker et al.,
2007). Pure water and sea water have the greatest dielectric permittivity, followed by saturated
sand, silt, and clay, and dry sand.
The relative permittivity is the primary factor controlling the speed for which EM
radiation travels through the subsurface. The EM-wave velocity is commonly referred to as
propagation velocity due to its relationship to reflector depth. The depth of a reflector involves
using time, velocity, and dielectric permittivity in the following equations:
d = tV/2 (2.8)
and
V = c/ϵ0.5 (2.9)
where d = reflector depth (m); t = two-way travel time (ns); c = velocity of light in free space
(0.3 m/ns); ϵ = relative dielectric permittivity, dimensionless; and V = EM-wave velocity (m/ns)
(Beres and Haeni, 1991). Also, because the propagation velocity is a function of distance and
29
time, it can be measured using the wavelength (λ, in m) and the frequency (f, in cycles per
second) of the radar-antenna frequency chosen where:
V = λf (2.10)
GPR surveys often employ frequencies between 100 and 1000 MHz, with higher frequencies
providing the greatest resolution, but limited in depth (Beres and Haeni, 1991). The antenna
chosen for this study (100 MHz) is a compromise between resolution and depth.
Although the propagation velocity of an EM wave is dependent on the relative
permittivity of a material, the amplitude and attenuation of a propagating wave is dependent on
the magnetic permeability and the electrical conductivity of the material. Magnetic permeability
is the ability of the material to become magnetized when an EM field is imposed on the material.
In SI units, permeability is measured in newtons per ampere squared (N/A2). As magnetic
permeability increases, attenuation of the signal increases; therefore, increased magnetic
permeability results in poorer data quality and or penetration depth (Baker et al., 2007).
Electrical conductivity also affects the propagation of EM waves because it measures how
capable a material is at conducting an electrical current. In SI units, conductivity is measured in
Siemens per meter (S/m). Materials with high electrical conductivity tend to attenuate EM
signals; therefore, highly conductive materials, such as clays, will produce poor GPR data and/or
reduce the penetration depth (Baker et al., 2007). In a fluvial environment, it is important to
consider the conductivity of dry sand and saturated sand, silt and clay. Dry sand having the
lowest conductivity and clay the highest. Values of dielectric permittivity and conductivity of
common materials can be found in Beres and Haeni (1991).
Resistivity is the reciprocal of conductivity and quantifies how a material opposes an
electrical current measured in ohm per m (Ω/m). Coarse grained sand and gravel are suitable for
30
GPR studies because they have high resistivity (Bristow and Jol, 2003) and are virtually
transparent to radio wave signals (Annan, 2005). The use of GPR is limited in fine-grained
sediments such as clays and silts, or areas with saline ground water, because these materials
attenuate radar signals (Bristow and Jol, 2003). Although the evaluation of sedimentary
structures is limited in clays and silts because the radio waves are often attenuated, this
attenuation can be an effective tool for delineating zones that impede water movement (Annan,
2005). The low hydraulic conductivity exhibited by these fine-grained materials often form a
barrier to groundwater flow and GPR’s sensitivity to water content can be used to map the water
table and perched water tables (Annan, 2005).
2.8 Meandering River Floodplains in Canada
As a general rule, floodplains form in response to a balance between vertical and lateral
accretion (Nanson, 1986). However, in most environments one process is expected to dominate
(Nanson, 1986). In a review of the primary floodplain formation processes, it has been stressed
by Leopold and Wolman (1957) and Miall (1996) that point bar deposits are dominated by lateral
migration (Thornbush 2001). This suggests that in-channel sedimentation processes, by way of
cut-bank erosion and point bar accretion, are more important to floodplain development than
overbank flow (Thornbush, 2001). In Canada, the dominant style of floodplain formation process
is strongly related to Quaternary sediments and landforms. For the Thames River in southern
Ontario (Stewart and Desloges, 2013), and select unconfined river reaches of the Nottawasga
(Thornbush, 2001), lateral accretion is confined to reaches bound by glaciolacustrine sand plains.
For the Beaton River in British Columbia, which is a tributary to the Peace River, glaciolacutrine
31
sands are also responsible for lateral migration in the otherwise bedrock confined valley
(Hartman and Clague, 2008).
However, in regions where till or glaciolacustine clay plains are seen outcropping
throughout a river reach, vertical accretion is expected to dominate. This is often related to the
increased bank strength of the glacial material and local to regional incision limiting lateral
migration. This style of floodplain development is characteristic of the semi-alluvial nature of
several southern Ontario rivers, including the Grand (Stewart and Desloges, 2013), the
Nottawasaga (Thornbush and Desloges, 2011), Saugeen (Garaci, 1998), and Humber rivers
(Weninger and McAndrews, 1989). Vertical accretion is also seen to dominate in the lower
reaches of the Red River, Manitoba (Brooks, 2002) where the riverbanks are predominantly
composed of silt-alluvium, characteristic to the glaciolacustine clay plain into which the river has
incised (Brooks, 2003).
It is important to know the dominant style of floodplain development because it helps
define how quickly a point bar is expected to migrate within a given period of time. For river
reaches confined by glaciolacustrine sands, the lateral migration is expected to be much higher
compared to river reached bound by till or clay plains. For example, the average lateral channel
migration rates for the sand-dominated Beatton River (British Columbia) is 0.475 m a-1 (Hickin
and Nanson, 1975). Conversely, the average lateral channel migration rate for the mud-
dominated Red River (Manitoba) is 0.04 m a-1 (Brooks, 2003), an order of magnitude slower
than sand-dominated river reaches. For southern Ontario, a river may flow through several
different quaternary sediments and/or landforms over a very short distance. Therefore, each river
reach could potentially behave much differently depending on its location within the basin.
32
In southern Ontario, the estimated average migration rate is expected to be 0.25 m a-1 (R.
Phillips, personal communication, October 2015). This migration rate conforms to observations
made on Nottawasaga’s sandy river reaches (Thornbush, 2001), the Humber River (Geomorphic
Solutions, 2011), but not the Thames River (Stewart and Desloges, 2013). On the Thames River,
the studied point bar lateral migration rate was measured to be 0.04 m a-1 to about 0.01 m a-1.
The rate of erosion and migration is expected to slow down as a river bend approaches resistant
valley walls (Geomorphic Solutions, 2011). Although the Thames River valley flows through a
belt of glaciolacustrine sand plains running north east to south west along the Mount Elgin
Ridges, it is also confined by glaciolacustrine clays on either side. It is therefore hypothesized
that the partial confinement of the Thames River valley by these clay plains may be responsible
for the slow migration of the studied point bar. It is, therefore, very important to consider the role
of Quaternary sediments and landforms on river morphology, in glaciated watersheds in Canada.
2.8 Research Questions
The prevailing research questions this study aims to address include:
1. What accretionary styles dominate point-bar formations in sand-bedded rivers of
glaciated southern Ontario, and do these point-bars conform to the classic fining-upward
depositional model?
2. What are the primary erosional and depositional elements found in the floodplains of
sand-bedded meandering rivers of southern Ontario, and do these elements correspond to
the accepted meandering facies model proposed by Miall (2010)?
3. To what extent does glacial inheritance influence channel morphology and channel
migration patterns/rates with respect to the imposed hydrological and sediment regimes?
33
Chapter 3: Study Area
3.1 Hydrology
In this study, five watersheds in southwestern Ontario were chosen to test the sand-
bedded meandering river facies model provided by Miall (1992, 2010) including the Ausable
River, Kettle Creek, Catfish Creek, Big Otter Creek, and Big Creek. Nine reaches amongst the
five watersheds were selected based on their accessibility, representative point-bar morphologies,
sandy boundary conditions and open topography for GPR. Figure 3.1 shows the five watersheds
and locations of each study reach along with respective gauge stations. The drainage area
upstream from each cross-section ranges between 350 and 863 km2, with study reaches on the
Ausable River having the greatest drainage areas, and Kettle and Catfish creeks having the
smallest. Drainage areas for each study reach were calculated using ArcGIS, flow accumulation,
and watershed polygon tools. These areas and their respective coordinates are listed in Table 3.1
below.
Climate in southern Ontario is temperate with warm summers and cold winters. For this
study region, the St. Thomas WPCP climate station data are available from Environment Canada
(2015) and is thought to be the most representative of climate for all the study watersheds. The
average annual temperature in this region, using a historical record between 1981 and 2010, is
8.7°C. The maximum recorded mean daily temperature reached is 38°C on June 25, 1988 and the
lowest minimum temperature of -31°C was recorded on Jan 16, 1984. Average annual
precipitation recorded between 1981 and 2010 is 993 mm. This average includes both rainfall
and snowfall throughout this period, totalling 874.4 mm and 118.6 cm, respectively.
34
Precipitation is quite consistent across all months of the year, with peak rainfalls occurring in the
month of September and peak snowfalls occurring in January.
Watershed Study
Reach Latitude Longitude
Average
Drainage Area
(km2)
Discharge (Qbf)
Big Creek 101 42°45'36.16"N 80°30'17.64"W 480 68.8
Big Otter
Creek
202 42°41'56.10"N 80°49'59.6"W 659 91.9
203 42°40'11.8"N 80°48'18.8"W 701 97.2
Catfish
Creek
301 42°42'18.85"N 81°02'46.91"W 350 51.6
302 42°40'33.40"N 81°02'25.20"W 376 55.1
Kettle
Creek 401 42°44'26.5"N 81°12'42.4"W 357 52.6
Ausable
River
503 43°04'42.8"N 81°36'42.1"W 826 112.8
504 43°04'7.93"N 81°38'19.78"W 854 116.3
505 43°03'56.2"N 81°41'12.1"W 863 117.4
Gauge
Station
Ausable
River 43°04'18'' N 81°39'35'' W 857 116.7
Big Creek 42°41'08'' N 80°32'18'' W 568 80.2
Big Otter
Creek 42°42'38'' N 80°50'26'' W 657 91.6
Catfish
Creek 42°44'45'' N 81°03'25'' W 294 44.0
Kettle
Creek 42°46'39'' N 81°12'50'' W 328 48.7
Weather
Station 42° 77’ N 81° 12’ W St. Thomas ON ID: 6137362
Table 3.1 - Drainage areas and bankfull discharge (Qbf) for each respective study reach and
gauge station. Qbf was calculated using discharge-area analysis discussed in Chapter
4.
35
Figure 3.1 – Five study watersheds chosen to test the sand-bedded meandering river facies
model.
Unlike precipitation, the magnitude of monthly discharge across the respective
watersheds is not uniform. Figure 3.2 illustrates the frequency of mean daily maximum flows for
each month across all watersheds for a maximum duration of 68 years between 1942 and 2013
and a minimum duration of 37 years between 1977 and 2013. For this region, it is clear that the
nival snow melt has a significant impact on daily maximum flows and frequency of events. The
months of January, February, March and April demonstrate the highest frequencies for daily
maximum flow, with the month of March contributing the most to total discharge.
36
Figure 3.2 - Flood frequencies, by month, of Maximum Mean Daily Flows across the five
studied watersheds in southern Ontario. Data Source: Water Survey of Canada
(2012).
3.2 Geology
The bedrock within the study area originated as sediments in the seas which covered this
area during the Devonian and Silurian Periods, approximately 400 million years ago (Sibul,
1969). The local geology for each watershed was determined using the Sanford (1969) Geology
Map, Toronto – Windsor Area. Each watershed is dominated by clastic sedimentary rock,
specifically the Middle Devonian Dundee Formation. Sanford (1969) divided this formation into
0
20
40
60
80
100
120
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Freq
uen
cy o
f Ev
ents
Month of Year
Flood Frequency Histogram - Mean Daily Maximum Flow
Ausable @ Springbank Big Creek @ Delhi Big Creek @ Walsingham
Big Otter Creek @ Calton Catfish Creek @ Sparta Kettle Creek @ St. Thomas
37
two members, the upper member of this group is composed of medium-brown microcrystalline
limestone, while the lower member is characterized as light-brown and tan crinoidal limestone,
containing quartz sand and chert. Flanking the western portion of the Ausable River, the Middle
Devonian Arkona Formation is composed of soft grey shales and mudstone. The lower reaches
of Kettle, Catfish and Big Otter creeks transition from the Dundee Formation to the Marcellus
Formation, which is described as black bitumous shale and minor limestone. The upper reaches
for each of Big Otter and Big creeks age from Devonian to Silurian passing north-east to south-
west through the Lucas Formation - Anderdon Member - a brown and tan microcrystalline and
sublithographic limestone; the Amherstberg Formation, a grey to dark-brown crinoidal limestone
and dolomite, locally cherty, bitumous and bistromal; the Bois Blanc Formation, a grey and
greyish brown dolomite, limestone, and nodular chert; the Bass Islands Formation, a cream and
tan oolitic microsucrosic dolomite; and the Salina Formation F Member, a grey and red shale
with lenses of anhydrite or gypsum. Bedrock outcrops in this region are however quite rare. The
present landscape is mainly the result of late Pleistocene glacial stages leaving a thick
overburden of glacial drift approximately 90 meters thick along parts of the Lake Erie shoreline
(Sibul, 1969).
The composition of these sedimentary rocks is important for the analysis of alluvial
sediment grain-size. When using laser diffraction to determine grain-size, the mineralogy is
important for the setting of optical parameters. Optical parameters for this study were based on
the composition of sedimentary rock observed in the area. The formations listed above,
demonstrate that the mineralogy of the study area is dominated by carbonate minerals, including
dolomite, calcite as well as bitumen enriched shales.
38
3.3 Physiography
There are several processes contributing to the physiography of southern Ontario
including plutonism, faulting of the sub-basement shield rock, epirogenesis of the Paleozoic
rocks, glaciation, isostatic adjustment, erosion, and weathering. However, the process having the
most profound impact on reshaping the surface geology of southern Ontario was the last glacial
maximum during the late Quaternary Period (Singer, 2003). Relief in southern Ontario is
diversified by the formation of glacial landforms, including drumlins, eskers, Kames, and
moraines. Within southern Ontario, 52 minor physiographic regions were delineated by
Chapman and Putnam (1984). These are illustrated in figure 3.3 and 3.4. The physiographic
features emphasized on this map include sand plains, clay plains, un-drumlinized till plains and
till moraines.
Sand plains in the study area are largest physiographic feature in the region, the largest of
which is the Norfolk Sand Plain. The Norfolk Sand Plain is a thick wedge with a curved base
along the Lake Erie shoreline, tapering northward to a point at Brantford on the Grand River,
covering 120 km2 (Lake Erie Region Source Protection Committee (LERSPC), 2014; 2008). The
Norfolk Sand Plains consist of lacustrine silts and sands deposited as a delta in glacial Lake
Whittlesey and Warren (Barnes, 1967; Sibul 1969) roughly 13,000 years ago (LERSPC, 2008).
Fine to medium-size sand grains are observed with sand-outwash bed thickness ranging between
27 m in the Tillsonburg area (Barnett, 1982) and 23 m at the bluffs of Lake Erie, with silt or clay
strata or beds of boulder clay seen nine m below the surface (Barnes, 1967; LERSPC, 2014). The
maximum thickness of sand-beds of the Norfolk Sand Plains is however difficult to accurately
determine, due to the formation of sand dunes throughout the area (Barnett, 1982).
39
Figure 3.3 - Physiography of southern Ontario, emphasizing the sand plains, clay plains, till
plains and till moraines relevant to the study area. River sampling points are in black
triangles and gauge locations are red squares. Data source: Chapman and Putnam
(2007, digital release date).
40
Figure 3.4 - Physiographic regions of southern Ontario, in the area of the five study watersheds.
Numbered sample sites are black triangles and red squares are the locations of
drainage gauges.
Clay plains are deposited in association with sand plains and they represent deeper water
offshore depositional environments (Dillon and Golder, 2004). These clay plains, also known as
the Ekfrid Clay Plains, are characterized by low relief and underlain by stratified clay and silt,
supporting pasture land rather than field crops due to poor drainage (LERSPC, 2008). The Ekfrid
Clay Plains were deposited before the Norfolk Sand Plains (dated at ~13,000 years ago), and
were left by glacial lake Maumee, roughly 14,000 years ago (LERSPC, 2008).
In addition to the extensive sand and clay plains, overburden is also composed of several
glacial till deposits. These deposits may be observed as till plains or as other glacial features,
specifically moraines within the study watershed, formed during the Late Wisconsinan
(LERSPC, 2014). In the Lake Erie Basin, the till plains are common to four of the five studied
41
watersheds and include the Catfish Creek Till, Port Stanley Till, and Wentworth Till. For the
Ausable River, the most prominent till plains in the region include Elma Till, Rannoch Till, and
the St. Joseph Till. Till plains observed in the Lake Erie basin are important for this study
because of their natural exposure in river banks along several of the study reaches.
Catfish Creek Till is the oldest and most extensive till in the study area, characterized as a
stony sandy silt hardpan (Barnett, 1982; LERSPC, 2014). Previously known as the “lower till”,
Catfish Creek Till get its name from its exposure along Catfish Creek (Barnett, 1982), however,
exposures are also reported in Kettle Creek and Big Otter Creek. This deposit represents a major
glacial advance that occurred during the Nissouri Stadial, 23,000 – 16,000 years B.P (Barnett,
1982; LERSPC, 2014). Deposition of Catfish Creek Till may be the result of several processes
including melt-out, debris flow, and lodgement. The complexity of the till’s formation results in
a fabric that is poorly developed, often demonstrating bimodal or multimodal grain-size
distributions (May et al., 1980). The silt-clay fraction of this till has a 40% carbonate content,
while the pebble lithology averages 80% carbonate. Munsell soil colours range from a greyish
brown (10 YR 5/2), brown (10 YR 5/3), dark brown (10YY 4/3), yellowish brown (10 YR 5/4),
and dark yellowish brown (10 YR 4/4) (Barnett, 1982).Whether sample colours were wet or dry
was not reported by Barnett (1982).
Port Stanley Till is the second oldest till in the region deposited during the Port Bruce
Stade (LERSPC, 2014). This till has a low clast content and grain-size is silt to silt-clay, ranging
in colour from brown to dark brown (10YR 5/3, 10YR 4/3), and yellowish brown (10YR 5/4) to
dark yellowish brown (10YR 4/4, 10YR 4/3) when oxidized. When sediment is not oxidized, the
colours range from grey (10 YR 5/1) to dark grey (10YR 4/1) and greyish brown (10YR 5/2) to
dark greyish brown (10YR 4/2) (Barnett, 1982). Carbonate content in the Port Stanley Till is
42
similar to the Catfish Creek Till (Barnett, 1982) at ~40%. Lacustrine sediments from Lake
Maumee are found separating Catfish Creek Till and the overlying Port Stanley Till layers
(Barnett, 1982; LERSPC, 2014). The Port Stanley Till itself is found with at least three different
layers, separated by similar lacustrine sediments (Sibul, 1969; Barnett, 1982).
The Wentworth Till is the youngest till found in the Lake Erie basin study area, confined
to the eastern corner of the study area near Delhi, ON. It mainly affects the Big Creek watershed.
There are few natural exposures of this till because it is buried below the Norfolk Sand Plains
(Barnett, 1982). The Wentworth Till has been described to have been deposited during the later
part of the Port Bruce Stadial (Barnett, 1982) around 1 x ka BP, refuting an earlier estimation for
deposition during the Port Huron Stadial (Barnett, 1982; LERSPC, 2014). No colours have been
recorded for the Wentworth Till in this area, which may have been used for comparison;
nevertheless, a carbonate content of 38% has been measured (Barnett, 1982).
Located between the Thames River Valley and the sand plains of Norfolk and Elgin
counties, the Mount Elgin Ridges stretch across the upper reaches of each Kettle, Catfish, Big
Otter and Big Creek. These ridges also separate the four Lake Erie watersheds from the Ausable
River, and control the surface water drainage pattern for each respective watershed. The Mount
Elgin Ridges are made up of several prominent moraines accounting for its name (Dillon and
Golder, 2004). These include the Ingersoll, Westminster, St. Thomas, Sparta, and Tillsonburg
moraines. These ridges are primarily made up of several Port Stanley Till layers, reaching a
maximum elevation of 298 m at the crest near Mount Elgin, ON (Barnett, 1982). The Mount
Elgin Ridges are known for their sandy nature (Dillon and Golder, 2004), whole valley bottoms
are characterized by glaciolacustrine silts and sands (LERSPC, 2014).
43
Chapter 4: Methods
4.1 Slope, Cross-Sectional Geometry, Drainage Area and Discharge
Stability and channel reach characterizations are dependent on the evaluation of hydraulic
geometry, slope, drainage area and discharge. Channel reach slope and hydraulic geometry for
each site was determined using a Sokkia CX-103 total station and Mesa data unit (Magnet
Software). Visibility limited the position of cross-sectional profiles and the length chosen for
channel slope determination; nevertheless, a total of 15 surveys were performed across the 5
watersheds. Cross-sections were matched to available cut-bank sediment profiles in as many
survey locations as possible. This was not always possible so a few cut-bank profiles were
logged off-section. The profiles were used to provide geomorphic determination of channel
width and depth at bankfull conditions. Steep breaks in bank slope, bank sedimentology and the
position of perennial vegetation were most useful in setting the bankfull position. Slope was
measured at water level (Sw) and is used to calculate total steam power (Ω) and specific stream
sower (ω) at channel reach scale.
Flood frequency analysis on each of the studied watersheds was performed using the
general extreme value distribution of the maximum daily flow for the annual maximum series
(AMS). The 2-year recurrence interval was calculated for each gauge station and plotted against
study reach and gauge station drainage areas. Discharge-area analysis was then used to calculate
reach specific discharges at bankfull flow. A power-law relation returned from this study’s river
reaches, matches the relationship determined by Phillips and Desloges (2014) for 146 study
reaches across southern Ontario. The power-law relationships determined by this study, Phillips
and Desloges (2014) and Annable (1996) include:
44
Qbf=0.25Ad0.91, this study (4.1)
Qbf=0.25Ad0.91, Phillips and Desloges (2014) (4.1)
Qbf=0.52Ad0.74, Annable (1996) (4.2)
Where Qbf id the bankfull flow, Ad is drainage area, and the coefficients and exponents are
empirically derived constants. To ensure the reproducibility of bankfull discharges in this study,
Phillips and Desloges (2014) power-law relation was ultimately used to calculate bankfull
discharges.
4.2 Longitudinal Profiles
Longitudinal profiles were extracted using data acquired from Phillips and Desloges
(2014) specific stream power mapping dataset. This dataset was constructed using elevation data
provided by Ontario’s provincial hydrologically enforced DEM, which has a 10 m x 10 m
resolution. Profile slopes were generalized using a 2.5 m vertical slice method and smoothed
using a 2 km moving window. Larger windows may be applied depending on each stream’s
characteristic profile; nevertheless, the 2 km moving window provided the best results for this
study.
4.3 Sedimentary Structures and Grain Size Analysis
To evaluate vertical trends of floodplain development in southern Ontario, 12 cut-bank
profiles and 3 soil cores were collected from 9 point-bar formations using a shovel and a 5 m
Environmental Soil Probe (ESP). From these, detailed grain-size distributions were measured for
5 cut-bank profiles and 1 soil core. Not all profiles or cores were measured due the time
commitment needed for pre-treatment and processing, but the analyses completed were
45
representative of the sedimentological characteristics of each survey section. Grain-size
distributions were measured using a Mastersizer 3000 and Hydro MV attachment (Malvern Ltd.,
UK). Sample preparation and methodology for determining grain-size are based on Murray
(2002), Sperazza et al. (2004), Ryzak and Bieganowski (2011), and van Hengstum et al. (2007).
Each of these stress the importance of organic material removal and the selection of appropriate
material property type (e.g. dolomite, calcite, carbonate, etc.) for setting of optical parameters.
However, first organic matter content was measured on an aliquot of each sample using loss-on-
ignition protocol provided by Heiri et al. (2001).
Preliminary grain-size tests were conducted using 11 sediment samples collected from a
single vertical cut-bank profile and 17 basal sediments collected from 12 cut-bank profiles, each
representative of all five river systems. These were done to establish an appropriate sample
preparation protocol. To remove organic material, a representative 1 ml aliquot was collected
from the field sample and placed in a 50 ml centrifuge tube. Drops of 35% Hydrogen Peroxide
(H2O2) were added to each sample until the vigorous reaction ceased. To speed up the reaction,
the centrifuge tubes were placed in a boiling water bath several times, adding peroxide when
required. After the reaction was complete and the removal of organic material was verified under
a microscope, the centrifuge tubes were filled with deionized water to 40 ml, centrifuged at 3000
RPM for 5 minutes each, and decanted using an aspirator. The decant process was repeated until
the solution stabilized at pH 7. Commonly, the removal of carbonates using hydrochloric acid
follows the peroxide pre-treatment for organics (Murray 2002); however, because the
composition of most sediment sources is composed of carbonate material (Sanford, 1969), this
step was not performed to avoid a misrepresentation of the clastic material deposited throughout
the river channel.
46
After organic material was removed, a few drops of 3% Calgon (sodium
hexametaphosphate) were added to the sample and set aside overnight. After a few preliminary
tests for stirrer speed, measurement duration, and material type, the Mastersizer 3000 and Hydro
MV attachment were set to analyze each sample for 3 consecutive measurements, 10 seconds in
duration, at a speed of 2500 RPM and 30% ultrasonication. The material property type chosen
was carbonate, with a refractive index of 1.69, absorption index of 0.1, and a density of 1 g cm-3.
Carbonate was chosen from three other tested material types (Silica, Calcite, and Dolomite)
common to the regional area. Carbonate performed the best in the preliminary analysis,
providing the lowest weighted residuals compared to the other three and demonstrated unimodal
distributions with the use of Calgon as a dispersant. The weighted residual is an effective
statistical tool because it is recognized as a measure of goodness of fit of a distribution model to
the observed data (Sperazza et al., 2004). For this study the model chosen is based on Mie theory
rather than Fraunhofer, which is why the optical properties of carbonate are required for the
analysis (Sperazza et al., 2004).
The average mean grain-size (D50) was used to aid in the classification of each
sedimentary unit within each cut-bank profile and soil core analysis. Percent clay, silt, sand, and
gravel based on the Wentworth classification scheme were used to aid in the classification of
lithofacies and facies units. Since gravel cannot be measured using the Malvern, a sample was
collected and sieved using 4mm, 2 mm, and 1mm mesh sizes representing the cobble, pebble,
and granule grain-size classes. These samples were weighed and a percent mass for each was
calculated. Grain-sizes less than 1 mm were analyzed using the Malvern and stitched to the final
result in excel. It is important to note that grain-sizes are determined by percent volume when
using the Malvern. When % mass and % vol measurements are combined, a user must consider
47
that there will be some error when interpreting the results. A full report of grain-size analysis
results, including sorting index, skew, and kurtosis is available in Appendix C.
LOI results were obtained using representative 1 ml aliquots collected from each field
sample, dried overnight at 105 °C and burned at 550 °C for 1 hour (Heiri et al., 2001). Samples
were stored in a desiccator for transport and cooling between measurements to prevent samples
from taking on moisture and to maintain the integrity of the result. Loss-on-ignition results are
useful for the environmental interpretation of sedimentary units because high organic matter
content may represent plant colonization and soil development during periods of surface
stabilization. A lack of vegetation may thus represent periods of active bar development.
In conjunction with photographs taken in the field, Nichols (2009) methodology was used
as a guide to interpret sedimentary structures and depositional processes observed in each cut-
bank profile. Primary structures associated with point-bar deposits include erosional and
reactivation surfaces following major flooding or storm events and channel rotation (Labrecque
et al., 2011). In sandy channels, the surface of a point-bar may be covered with migrating
subaqueous ripples and dune bedforms, resulting in the formation of cross-laminated or cross-
bedded sand units, respectively. These features are sorted under decreasing depth and velocities
and may be planar, tabular or trough shaped depending on the presence of an erosional surface
(Nichols, 2009).
4.3 GPR Analysis Methods
Ground Penetrating Radar (GPR) was used to profile the depositional environment of
eight point-bars across the five sand-bedded rivers in this study. Single straight-line GPR
reflection surveys were conducted perpendicular and parallel (some) to flow for a generalized
evaluation of depositional patterns. Radar reflections were obtained using a pulseEKKOTM IV
48
GPR unit with 100 MHz center-frequency antennas and the common-offset, single fold
reflection, profiling mode. Antennas were placed in a perpendicular broadside position with an
antenna separation of 1 m. Reflections were collected with 64 stacks per trace in step-mode, at a
0.25 m sampling interval. For quality control, a rugged data display recording DVL was used to
monitor the real-time profile for structures, anomalies, and field error.
A 15 m common midpoint (CMP) survey was conducted in the field to determine local
propagation velocities. This survey was conducted at all GPR sites and applied to each
corresponding reflection survey for an accurate representation of floodplain thickness for each
point-bar surface.
GPR data are presented as a series of amplitude wiggle traces, whereby each wiggle
represents an average of the 64 individually stacked traces. CMP surveys to determine velocities
were processed using EKKO_Project advanced GPR software (Sensors and Software Inc., 2014)
CMP surveys were collected and an average velocity of 0.067 m ns-1 was determined. This
velocity is consistent with the expected velocity of saturated sands (0.06 m ns-1; Leucci, 2012)
and offers confidence to calibrated true depth measurements.
Spreading and exponential compensation (SEC2) gain was also used to amplify the
strength of the signal with depth. Due to the nature of GPR signals through geologic material, it
is common for the strength of the signal to become exponentially weaker with depth; this results
in a profile with masked or concealed reflectors. Weak reflectors are recovered using gains, such
as SEC2 and Automatic Gain Control (AGC), after a graphic comparison between the two, the
SEC2 was chosen based on better performance for the given study material. Topographic
correction was not performed for these profiles because the floodplain surface is relatively flat. A
correction to the topography would have minimal impact on the final interpretation.
49
Chapter 5: Results
5.1 Introduction
To characterize the mechanisms that control channel and floodplain development in sand-
bedded rivers of southern Ontario, studied reaches were divided into three primary floodplain
subtypes as defined by the theories of channel pattern discrimination, erosional and depositional
processes, landforms, and sinuosity. Using data acquired from cross-sectional surveys, floodplain
sampling, stratigraphic profiles and GPR, these sand-bedded rivers are evaluated to define
primary processes of floodplain development, specifically accretionary style and assemblage of
architectural elements.
Bankfull morphology, hydrology, and floodplain sedimentology of each site surveyed is
presented in Table 5.1. Table 5.2 stratifies these river reaches by their position upstream and
potential specific stream power. There is also a considerable difference in channel slope,
sinuosity, and assemblage of architectural elements between these floodplain subtypes. These
floodplain subtypes are reviewed in detail to validate the main processes and mechanism
responsible for floodplain development and are compared to the standard classic fining-upward
point-bar depositional model and the meandering sand-bedded river facies model. Table 5.3
represents the primary lithofacies observed in cut-bank sediment profiles in this study.
Moreover, Figure 5.1 reviews common GPR reflection configurations. These reflection
configurations are used to interpret the primary depositional and erosional processes common to
meandering sand-bedded rivers.
Primary depositional and erosional processes identified in point-bar formations of
southern Ontario are summarized by five radar facies as listed in Table 5.4 This table provides a
50
thorough evaluation of architectural elements identified, principal facies assemblages, and
description of corresponding reflection configurations and interpretation of depositional
environment.
To evaluate the effect glaciation has had on river channel morphology and lateral
migration, slope-area analysis and constant stream power curves (with a power-law exponent of -
0.4) are used to discriminate between glacially conditioned river reaches and expected planform
morphologies. Longitudinal profiles are plotted against specific stream power to assess the
influence glacial landforms have on slope and migration rates are calculated to accesses the
effect changing boundary materials have on vertical and lateral accretion.
51
Site Characteristics Big Creek Big Otter Creek Catfish Creek Kettle Creek Ausable River
101 202 203 301 302 401 503 504 505
Drainage Area (km2) 480 659 701 350 376 357 826 854 863
% Total Drainage Area 83.8 93.2 99.2 88.4 94.9 83.8 69.9 72.3 73
Distance from outlet (km) 43.0 12.9 3.8 14.3 5.55 17.1 69.5 63.1 52.4
Channel Slope 0.00078 0.00053 0.00011 0.00169 0.000095 0.00223 0.00086 0.00081 0.000096
Channel Morphology
Width (m) 17.2 26.4 32.9 30.2 24.8 31.3 37.6 41.9 24.1
Depth (m) 3.35 3.40 3.62 3.09 3.50 1.95 2.81 2.96 2.78
Width:Depth 5.12 7.77 9.10 9.75 7.08 16.1 13.4 14.2 8.70
Cross-Sectional Area (m2) 57.5 89.9 119.07 93.3 86.8 60.9 13.4 124 26.9
Sinuosity 1.4 1.9 2.1 1.5 2.0 1.2 1.6 1.9 2.1
Channel Hydrology
Discharge (m3s-1) 68.8 91.9 97.2 51.6 55.1 52.6 113 116 117
Total Stream Power (W m-2) 527 473 108.4 853 51.0 1147 953 927 110
Specific Stream Power (W m-2) 30.7 17.9 3.29 28.3 2.06 36.6 25.3 22.1 4.58
Floodplain sedimentology
Overbank thickness (m) 2.20 4.28 3.89 1.65 4.28
Clay Content (%) 1.93 1.20 1.45 1.92 2.60
Silt Content (%) 28.9 18.3 15.2 19.4 17.8
Sand Content (%) 69.2 80.5 83.3 61.3 79.6
Organic Content (%) 2.29 1.12 1.14 1.57 3.16
Table 5.1 - Bankfull channel and floodplain characteristics derived from 2-year recurrence interval for Maximum Daily Discharge
plotted against Drainage Area
52
Type Stability
and
Boundary
Material
Erosional and
Depositional Processes
Landforms Specific
Stream
Power
(W m-2)
Sinuosity Representative
Study Reaches
High Energy,
Upper-
Watershed
Reaches
Moderate
instability,
sand-
gravel bed
Abandoned channel
accretion; overbank
vertical accretion; minor
lateral accretion; and
minor downstream
accretion.
Undulating floodplains of
abandoned channels,
longitudinal bars, and
backswamps.
28-37 ≤ 1.5 101, 301 and 401
Medium
Energy,
Middle-
Watershed
Reaches
Stable,
sand-bed
Cut-bank erosion; lateral
point-bar accretion; and
overbank vertical
accretion
Flat to undulating
floodplain surface, oxbow
lakes, and backswamps.
No evidence of mid-
channel bar development.
18-25 1.6-1.9 202, 503 and 504
Low Energy,
Lower-
Watershed
Reaches
Stable,
sand-bed
Cut-bank erosion; lateral
point-bar accretion;
overbank vertical
accretion; and minor
oblique accretion
Flat to undulating
floodplain surface, oxbow
lakes, and backswamps.
No evidence of mid-
channel bar development.
< 5 ≥ 2.0 203, 302 and 505
Table 5.2 - Description of meandering channel floodplain types for sand-bedded rivers in southern Ontario.
53
Facies Code Description Interpretation
Gcm Massive clast-supported gravel/cobble; not imbricated; structureless Lag deposits
St Sand, fine to very coarse, may be pebbly; solitary or grouped trough
cross-beds
Sinuous crested and linguoid 3-D
dunes
Sp Fine to very coarse, may be pebbly; low angle ( < 15°) planar cross-
beds, solitary or grouped Transverse and linguoid 2-D dunes
Sr Sand, very fine to coarse; ripple cross laminations Ripples
Sm Sand, fine to coarse, massive with possible faint laminations Flood deposits
Fl Sand, silt and mud; fine laminations and possible fine ripples Overbank flow, abandoned channel, or
waning flood deposit
Fsm Silt and mud, some sand; massive and structureless Back-swamp or abandoned channel
deposit
Fm Mud and silt, massive, some faint desiccation cracks Overbank, abandoned channel, or
drape deposits
Fr Composed of mud and silt; massive, roots and bioturbation; elevated
%OM when compared to other sedimentary units
Incipient or antecedent soil layer or
root bed.
S Massive structureless sand, medium to fine texture Possible Pleistocene Norfolk Sand
Plains, or reworked Sand Plain deposit
F Massive silty sand deposit, some fine gravel; hardpan difficult to
excavate. Possible glaciofluvial origin
P Antecedent soil layer or paleosol, commonly capped by thick post-
settlement alluvium (PSA). Soil with chemical precipitation
Table 5.3 – Common lithofacies observed in studied river reaches of southern Ontario, adapted from Miall (2010) and results from this
study
54
Figure 5.1 - Common seismic reflection patterns observed from GPR reflection surveys,
modified from Beres and Haeni (1991) and Mumpy et al. (2007).
55
Radar
Facies
Architectural
Element Symbol
Principal
Lithofacies
Assemblage
Description
1 Lateral accretion LA St, Sp, Sm Low to high-angle (12-21°), cross-stream dipping, sigmoid-
subparallel reflection configuration interlayered with silt and sand
associated to point-bar sediments.
2 Vertically
accreted
floodplain fines
FF Fsm, Fl, Fm,
Fr
Subhorizontal, continuous, subparallel reflections. May be referred
to as overbank fines (OF) and observed as thick or thin sand sheets
in channel-fill deposits or floodplain environments, paleosols, and
crevasse splays.
3 Abandoned
channel accretion
CH(FF) Fsm, Fl, Fm,
Fr
2-D erosive basal contact surface, concave-up to the sky commonly
filled with vertically accreted floodplain fines
4 Abandoned
channel accretion/
meander-loop
lateral accretion
CH(LA) S, Sp Low angle (4-12°), sigmoid-subparallel reflections dipping away
from channel into the floodplain. Lower element boundary
represents concave-up channel
5
Underlying
glacial deposit
F
S – Norfolk
Sand Plain
F –
Glaciofluvial
sediments
Gcm – Till
S – glacial deposits composed of sand may be observed as reflection
free deposits with depths greater than the modern channel;
F – attenuation into deposits of possible glaciofluvial origin is high,
with increased loss of signal with depth;
Gcm – these deposits are accompanied by high amplitude
discontinuous reflectors and hyperbolic diffractions (associated to
logs or boulders)
Table 5. 4 – Description and interpretation of radar facies common to sand-bedded meandering rivers in southern Ontario, adapted
from Halfar et al. (1998), Miall (2010), Woolridge and Hickin (2005) and results from this study.
56
5.2 High Energy, Upper-Watershed Reaches
Big Creek site 101, Catfish Creek site 301, and Kettle Creek site 401 are examples of
high energy upper-watershed sand-bedded meandering river reaches in southern Ontario. Site
101 resides in the heart of the Norfolk Sand Plains as indicated by the physiographic maps in
Figures 3.3 and 3.4. Site 301 and site 401 also reside within the Norfolk Sand Plains, just south
of the St. Thomas Moraine. Channel slopes for these reaches are 0.00078, 0.00169, and 0.00223
m m-1; site 101 having the lowest slope, followed by 301 and 401, respectively. Sinuosities for
each reach are ≤ 1.5 and specific stream powers range between 28 and 37 W m-2.
Given that sinuosities for meandering river reaches are typically greater than 1.5 (Dey,
2014), these planforms may be defined as meandering-straight, high energy, headwater reaches.
Theories of channel pattern discrimination illustrated in Figure 5.2, further classifies these rivers
based on Leopold and Wolman’s (1957) meandering-braiding threshold slope and Kleinhans and
van den Berg’s (2011) discrimination between sand- and gravel-bed rivers. The results
demonstrate that these upper reaches are, for the most part, stable sand-bedded meandering
rivers. However, the intermediate position of reaches 301 and 401 suggest that there is potential
for moderate instability and gravel at each. Specific stream power-area substantiates the Leopold
and Wolman (1957) meandering planform discrimination, as stream energy for each studied
reach falls within the theoretical stream power domain for meandering river planforms (10-60 W
m-2). This theoretical domain is shaded in grey on the graph in Figure 5.3.
57
Figure 5.2 - Discrimination between laterally stable sand-bedded river reaches to laterally
unstable gravel-bed rivers, adapted from Leopold and Wolman (1957) and Kleinhans
and van den Berg (2011).
0.00001
0.0001
0.001
0.01
0.1
1 10 100 1000 10000 100000
Slo
pe
, S
(m m
-1)
Discharge, Qbf (m3 s-1)
LATERALLY STABLE
LATERALLYUNSTABLE
58
Figure 5.3 - Specific stream power-drainage area analysis plotted for 9 studied river reaches in
southern Ontario. The shaded area represents the theoretical domain for meandering
river floodplains (10 – 60 W m-2) as defined by Nanson and Croke (1992). Mean
specific stream power (�̅� = 19 W m-2) for this study is represented by the solid black
line.
Field reconnaissance and photographs provided in Figure 5.4 confirm the presence of
gravel at sites 301 and 401, but not 101; as predicted by Kleinhans and van den Berg (2011;
Figure 5.2). Additionally, these photos provide evidence of mid-channel gravel-bar development
in each of 301 and 401, suggesting coarser bedload transport for reaches located closer to
moraines.
59
Accretionary style for high energy, upper-watershed reaches was evaluated using
sedimentary profiles for sites 101 and 401. The location where these sediments were collected
within the reach may be reviewed in Figure 5.4. Also provided in Figure 5.4 is a photograph and
hill-shaded map of the surveyed reaches. Hachures on the hill-shaded map indicates the location
of Pleistocene alluvial terraces.
As predicted, Big Creek site 101 is sand-bed with no gravel. Despite the headwater
position of this reach, site 101 is unaffected by the coarse sediment supply offered by the
morainic ridges in the region. The sand plains in this region are reported to be 25 m thick west of
the Galt Moraine (LERSPC, 2008), within the Big Creek watershed. The sedimentary log for site
101, illustrated in Figure 5.5, demonstrates a coarsening-up vertical profile, characterized by a
fine-grained Fsm lithofacies at the base followed by a succession of Sm and Fm lithofacies units.
The Fsm lithofacies is characterized by gleyed and mottled sandy silt deposit. This deposit is
massive, structureless, and possibly related to a backswamp or abandoned channel depositional
environment. The Sm lithofacies represent sediment deposited by a flood, mainly composed of
sand, while the Fm lithofacies are composed of fine silts. They are massive and are often
characterized by desiccation cracks. Fm lithofacies are also indicators of floodplains primarily
formed by vertical accretion.
Capping this profile is an Fr lithofacies, representing the root bed and incipient soil. This
layer is followed by a thin modern flood deposit (Sm lithofacies) with a percent organic material
(% OM) of less than 3%. OM greater than 3% is concentrated to the Fr/Fm lithofacies illustrated
in Figure 5.5, below this lithofacies OM declines substantially. More information on % OM is
presented in Appendix C.
60
Figure 5.4 – High energy, upper-watershed meandering river reaches - Big Creek Site 101, near
Langton, ON; Catfish Creek Site 301, near Sparta, ON; and Kettle Creek Site 401,
near St. Thomas, ON. The green dots the respective locations of cut-bank sediment
profiles.
101
42°45’51” N
42°42’42” N
42°44’44” N
81
°29
’47
W8
1°0
2’1
1”
W8
1°1
1’5
9”
W
61
Figure 5.5 - Big Creek Site 101 Sedlog, near Langton, ON; sediment collected upstream from the
point-bar meander apex, as illustrated by the green dots in Figure 5.4.
Similar to site 101, overbank vertical accretion dominates the accretionary style for site
401 at Kettle Creek. The floodplain surface 0.07-0.57 m below the surface, is composed of mud
and silt, with roots, bioturbation, and an elevated % OM. Like site 101, this layer is classified as
Fr lithofacies and defined as the incipient soil layer and root bed. Below the Fr lithofacies, Fm
lithofacies are observed composed of mud and silt, and characterized by faint desiccation cracks.
Next, Fl lithofacies are observed and defined by faint sand laminations, separated by Sm
lithofacies flood deposits. Below the FI/Sm lithofacies, transverse and linguoid dune structures
are observed are classified here as Sp lithofacies.
62
Figure 5.6 – Kettle Creek Site 401 Sedlog, near St. Thomas, ON; sediment collected upstream
from the point-bar meander apex, as illustrated by the green dots in Figure 5.4. The
D50 markers indicated in red are samples that required stitching of %vol and %mass
grain-size measurements. Bone material is marked in red.
Buried in the Sp lithofacies the first right rib of an adult Artiodactyla (Elk), from the
family Cervidae was extracted and radiocarbon dated. The bone was identified using the Howard
Savage Faunal Archaeo-Osteology Lab Collection at the University of Toronto. The size and
63
shape of the bone suggest that it is most likely an elk bone (wapiti in Iroquois language). The
wapiti were extirpated by 1850 in southern Ontario, due to excessive hunting since 1750.
(Peterson, 1966; Rogers and Smith, 1994). The bone was located 1.20 m below the floodplain
surface and 0.12 m above the Gcm lithofacies. The date returned was modern, 200 ± 30 years,
suggesting an average accumulation of 0.6 cm of sand since the animals death and burial.
Preceding the Sp lithofaces, a Gcm gravel lag deposit is logged. This unit is structureless,
non-imbricated, massive and clast-supported. The gravel extends down to the surface of the
water, after which hardpan silt is observed lining the bottom of the channel. This pattern is also
observed at site 301 on Catfish Creek, as shown in Figure 5.7 below. With gravel at the base and
silty sand on the surface, the sediment profile logged at site 401 on Kettle Creek conforms to the
traditionally accepted fining-upward point-bar deposition model.
Figure 5.7 – Catfish Creek Site 301, photographic evidence of silt hardpan and gravel.
Photograph (A) silt bed, resembles sandy silt hardpan of possible glaciofluvial origin.
(B) Exposure of gravel lag deposit.
(A) (B)
64
Architectural elements for high energy, upper-watershed reaches of southern Ontario are
defined by ground-penetrating radar at Kettle Creek site 401. Two 100 m reflection surveys were
collected, processed, and interpreted in Figures 5.9 and 5.10 below. These reflections were
surveyed parallel and perpendicular to channel flow, as illustrated in Figure 5.8. Using the GPR
reflection surveys, reflection configurations were mapped and radar facies identified. The radar
facies (architectural elements) characterizing depositional and erosional floodplain formative
processes in high energy, upper-watershed reaches include: (1) lateral accretion (LA), (2)
vertically accreted floodplain fines (FF), (3) abandoned channel accretion (CH(FF), and (5)
underlying glacial deposits (F).
Figure 5.8 – GE image of the surveys conducted at Kettle Creek Site 401, near St. Thomas, ON;
complete with the respective locations of cross-section surveys, GPR surveys, and
cut-bank sediment profiles.
42°44’26” N
81
°12
’42
” W
65
The architectural element dominating this floodplain’s formation is abandoned channel
accretion (CH(FF)). This architectural element is defined by a 2-D basal erosion surface,
concave up to the sky. These features have complex fills and oblique subparallel reflections. The
principal lithofacies assemblage for CH(FF) surfaces include Fsm, Fl, Fm, and Fr, which are
very fine sediments deposited in suspension. Normally the base of abandoned channels is coarse,
which is confirmed by the hyperbolic features indicated in red along the lower boundary surface
and the cut-bank sediment profile evaluated in Figure 5.6 above.
The widths and depths of these abandoned channels are quite similar to the current
channel width and depth of 31 m and 1.95 m, respectively. Three abandoned channels are
observed at site 401 suggesting moderate instability in the floodplain, validating the prediction
for moderate instability of this reach (see in Figure 5.2).
The second most dominant architectural element observed in the floodplain, is radar facies
(2), vertically accreted floodplain fines (FF). The principal facies assemblage for vertically
accreted sediments include fine-grained Fsm, Fl, Fm and Fr. The reflections are subhorizontal,
continuous and subparallel, extending across the floodplain and are followed by minor laterally
accreted floodplain sediments, recognized as radar facies (1).
Radar reflections in Figure 5.9 reach 5 m into the floodplain subsurface before radar
signals are attenuated abruptly into radar facies (5). Radar facies (5) represents underlying glacial
deposits. A reflection free configuration with diffractions is indicative of massive sediments with
boulders or large cobbles (Beres and Haeni, 1991). These diffractions are illustrated as red
hyperbolas in Figure 5.9 and 5.10. Diffractions eventually subside, leaving a reflection free
configuration from ~4 m below the floodplain surface.
66
Figure 5.9 – Upstream raw and interpreted GPR reflection survey collected at Kettle Creek Site
401, near St. Thomas, ON. This profile was conducted parallel to flow at the apex of
the meander bend. Radar facies are indicated numerically and may be reviewed in
Table 5.4.
67
Figure 5.10 – Raw and interpreted GPR reflection survey collected at Kettle Creek Site 401, near
St. Thomas, ON. This profile was conducted perpendicular to flow at the apex of the
meander bend. Radar facies are indicated numerically and are defined in Table 5.4
68
Given the position of Kettle Creek site 401 cutting through the Mount Elgin Ridges radar
facies (5) may represent Catfish Creek Till, which has been observed frequently throughout the
Kettle Creek watershed (LERSPC, 2014). Moreover, the Catfish Creek Till is composed of
stony, sandy silts (Barnett, 1982) fitting the configuration of radar facies (5) as being reflection
free with diffractions as illustrated in Figure 5.6.
5.3 Medium Energy, Middle-Watershed Reaches
River reaches residing in medium energy, mid-watershed positions include Big Otter
Creek site 202 and Ausable River sites 503 and 504. Like Big Creek, Big Otter Creek is situated
in the heart of the Norfolk Sand Plains. However, sites on the Ausable River are bound by shore-
parallel horseshoe moraines, contributing to the river’s curved trajectory into Lake Huron.
Pleistocene sediments, characteristic of the Ausable River include clay and till plains, as
illustrated in Figures 3.3 and 3.4. Channel slopes for these reaches are 0.00053, 0.00086, and
0.00081 measured at water level for each of reaches 202, 503, and 504 respectively. Sinuosities
for rivers in the medium energy group vary between 1.6 and 1.9, with specific stream powers
ranging between 18 and 25 W m-2.
Sinuosities of these rivers conform nicely to the expected sinuosities of meandering river
reaches (> 1.5) (Dey, 2014). Moreover, specific stream powers fit well within the theoretical
domain for meandering river reaches (10-60 W m-2). Leopold and Wolman’s (1957) meandering-
braiding threshold slope and Kleinhans and van den Berg (2011) stream power thresholds for
sand and gravel beds, define these rivers as stable meandering river reaches (Figure 5.2).
69
Like Kettle, Catfish, and Big creeks, Big Otter Creek and the Ausable River are
significantly entrenched, illustrated by hachures along alluvial terraces in Figure 5.11, and bank
heights exceeding 4 m, as defined by the sedimentary log graphed in Figure 5.12. For Big Otter
Creek, where the sampled bank height very much exceeded 4 m, the very sandy nature of the
bank, this profile was divided into 4 sampling steps in order to clearly illustrate the diversity of
sedimentary units.
The position of each bank sampling step at site 202, relative to the water level, was tied
to the same datum using the total station. Sedlogs were drawn to account for overlap between
sedimentary units between sampling steps. In Step 1 of the vertical profile, it is clear that vertical
accretion dominates, extending ~1.25 m below the floodplain surface. This accretion style is
marked by fine grained sedimentary units, namely Fr, Fl, and Fm lithofacies, deposited during
overbank flow. Some of these deposits are separated by coarser modern Sm flood deposits,
illustrated by their lighter colour and elevated % sand. From 1.5 m below the floodplain surface
to ~ 3.25 m, laterally accreting sediments are logged. The vertically and laterally accreted sand
units are separated by an upstream dipping transverse sigmoid 2-D dunes, commonly found
toping point-bar surfaces (Woolridge and Hickin, 2005).
Laterally accreted sedimentary units are identified by Sp, Sm, and Fm lithofacies. Sp and
Sm lithofacies are characteristically very sandy and contain structures with varying degrees of
compaction representing transverse and linguoid 2-D dunes. Overbank deposits separating some
of the laterally accreted sedimentary units are characterized by finer grained material dropped in
suspension. These layers are darker in colour (e.g. very dark greyish brown, 10YR 3/2),
displaying a modest increase in % OM, and possibly marks a short period of bank stabilization.
70
Figure 5.11 – Medium energy, middle-watershed meandering river reaches: Big Otter Creek Site
202, near Calton, ON and Ausable River Site 503, near Springbank, ON. Hill-shaded
site maps (right) illustrate the location of alluvial terraces and the green dots indicate
the location of the cut-bank sediment profiles analyzed in this study.
42°42’40” N
80
°48
’55
” W
81
°40
’36
” W
43°04’12” N
43°05’0.6” N
81
°36
’12
” W
71
Despite the elevated % OM in these overbank deposits, % OM rarely exceeds 2% throughout the
profile, suggesting that bank site 202 on Big Otter Creek may be rapidly migrating.
Figure 5.12 - Big Otter Creek Site 202 Sedlog, Step 1 of 4 from 0 to 1.9 m. Sediment was
collected at the apex of the meander bend, in line with the GPR reflection profile
(See Figure 5.18).
72
Figure 5.13 - Big Otter Creek Site 202 Sedlog, Step 2 of 4 from 1.8 m to 2.6 m. Sediment was
collected at the apex of the meander bend, in line with the GPR reflection profile
(See Figure 5.18).
Nearing water level, 3.8 m below the floodplain surface, there is a thick structureless
sand unit divided into three sedimentary units (Step 4, Figure 5.15). The first and second units
3.4-3.88 m from the surface are characterized as an S lithofacies, composed of fine-medium
sands, dark brown (10YR 3/3) to dark yellowish-brown (10YR 3/4) in colour. Below this unit
from 3.88-4.06 m below the floodplain surface is a thick Fsm deposit, composed of silt-sand and
mud, and dark olive-brown (2.5YR 3/3) colour. The lowest sedimentary unit begins at 4.06 m
and its total thickness is unknown. This deposit is characterized as olive-brown (2.5YR 4/3) in
colour and fine to coarse sand in texture. Based on texture and colour alone, it is hypothesized
that a transition exists within these basal layers from the Pleistocene Norfolk Sand Plains to an
overlying Holocene point-bar macroform. Nevertheless, the exact position where the Norfolk
73
Sand Plain deposits end and the point-bar macroform begins, is difficult to interpret without
detailed chronological control.
Figure 5.14 - Big Otter Creek Site 202 Sedlog, Step 3 of 4 from 2.3 m to 3.5 m. Sediment was
collected at the apex of the meander bend, in line with the GPR reflection profile (see
Figure 5.18).
.
74
Figure 5.15 - Big Otter Creek Site 202 Sedlog, Step 4 of 4 from 3.25-4.25. Sediment was
collected at the apex of the meander bend, in line with the GPR reflection profile (see
Figure 5.18).
A radiocarbon date was derived from a large piece of wood extracted at the base of Step
4, Big Otter Creek site 202. The wood has an age of 8670 ± 30 years BP. This wood sample is
likely spruce or pine, each native to the Norfolk Sand Plains (Niewójt, 2007). One possibility is
that this wood is very old, re-worked, material that has been deposited by recent fluvial
processes. However, a second possibility is that this wood is remnant of the open spruce
parkland paleovegetational zone, which is said to have persisted from at least 12,950 ± 220 years
until approximately 9840 ± 140 years BP (Barnett, 1982), or the boreal forest zone which also
persisted ~10,000 years BP (Barnett, 1982). Since glacial lake stages terminated ~12,000 years
75
BP in this region, this sedimentation zone may represent in situ deposition of the wood during
post glacial Lake Erie stages 12,000 to 7500 years BP when the early river was formed in an
emerging landscape (Herdendorf, 2013).
Despite challenges interpreting the depositional environment of the basal sediments in the
cut-bank profile at Big Otter Creek, site 202, the coarser underlying sand unit at 4.25 m,
transitioning to laterally accreted surfaces and vertically accreted fine grained sand cap, fits the
vertical fining-upward point-bar depositional model provided by Miall (1992, 2010).
The dominant accretionary style at Ausable River, site 504, is vertical accretion with no
laterally accreting sediments or associated structures observed. Vertically accreted sediments are
recognized as Fm and Fr lithofacies. Fm lithofacies are composed of more sand rather than the
silt (60%) and mud (10%) observed in the Fr lithofacies. Also, Fm lithofacies are characterized
by faint desiccation cracks, while Fr lithofacies are bioturbated. The classic fining-upward
deposition is observed in this bank, beginning at 2.10 m below the floodplain surface; below this
a few Fsm lithofacies were logged. These Fsm lithofacies are characterized as very silty deposits,
but there is also some sand, fine to medium in texture. This deposit is interpreted as backswamp
or abandoned channel deposit with a %OM value > 5%, the highest value reported throughout
the profile at site 504 on the Ausable River. When compared to Big Otter Creek, the Ausable
River, site 504, demonstrates a similar depositional model (fining-upward), however sediments
are much finer grained; owing to its position in the siltier clay and till plains, located in the
valleys of the Horseshoe Moraines (Luinstra et al., 2008).
76
Figure 5.16 - Ausable River Site 504 Sedlogs, sediment collected upstream from meander apex,
as illustrated by the green dot in Figure 5.11.
Architectural elements for medium energy mid-watershed reaches of southern Ontario are
defined by ground-penetrating radar at Big Otter Creek site 202. Three reflection surveys were
conducted on this site, two of them are shown here. Each survey was conducted perpendicular to
the channel bank as illustrated in Figure 5.17. Radar facies identified in Figures 5.18 and 5.19
include (1) lateral accretion macroforms (LA), (2) vertically accreted floodplain fines (FF) and
(3) abandoned channel accretion (CH(FF), Laterally accreteing elements are characterized by
steeply sloping, cross stream subparallel relfection configurations common to point-bar
depositional environments; while vertically accreted elements are represented by subhorizontal,
77
continuous, subparallel reflections. Abandoned channel architectural elements in this floodplain
are quite large, with an erosive concave-up boundary surface width reaching 26 m. These widths
are consistent with the modern channel width.
Reflections in each survey reach depths of ~4.0 m before the signal is attenuated and
basal sand units have a reflectionless radar configuration. A reflectionless radar configuration
may represent attenuated energy, silty lacustrine sediments, massive thick-bedded sand or till
(Beres and Haeni, 1991). At Big Otter Creek site 202, the reflection free configuration of basal
sand units, points to massive or thick sand given that a thick structureless sand-bed observed in
the cut-bank sediment log (see Figure 5.15). In this log the basal units are interpreted as a change
in depostional environment 4 m below the floodplain surface. If the depositional environment
has changed from either Pleistocene Norfolk Sand Plains or post glacial lake stages, radar facies
(5) which represent deposits with glacial origin (see Table 5.3) may also be appropriate for GPR
surveys conducted at Big Otter Creek site 202.
Figure 5.17 - GE image of the surveys conducted at Big Otter Creek Site 202, near Calton, ON;
complete with the locations of each cross-section survey, GPR survey, and cut-bank
sediment profiles.
42°42’07” N
80
°49
’43
” W
78
Figure 5.18 - Upstream raw and interpreted GPR reflection survey collected at Big Otter Creek
Site 202, near Calton, ON. This profile was conducted perpendicular to flow on the
upstream corner of the meander bend. Radar facies are indicated numerically and
may be reviewed in Table 5.4
79
Figure 5.19 - Raw and interpreted GPR reflection surveys collected at Big Otter Creek Site 202,
near Calton, ON. This profile was conducted perpendicular to flow at the apex of the
meander bend. Radar facies are indicated numerically and are taken from Table 5.4
80
5.4 Low Energy, Lower-Watershed Reaches
River reaches occupying the lower parts of watersheds include Big Otter Creek site 203,
Catfish Creek site 302, and the Ausable River site 505. Site 203 and 302 are situated in the heart
of the Norfolk Sand Plains, as illustrated in Figure 3.3 and 3.4; while the Ausable River site 505,
resides in close proximity to 504 and 503, sitting in the clay and till plain valleys of the Lake
Huron horseshoe moraines. Channel slopes for these river reaches are 0.00011, 0.000095, and
0.000096 m m-1 respectively, for 203, 302 and 505. Sinuosities for each river are ≥ 2.0, with
specific stream powers < 5 W m-2.
Sinuosities of these rivers are above the middle range “normally” meandering river (1.5
t0 2.0) (Dey, 2014). Specific stream powers fall well below the upper threshold for meandering
river reaches (10-60 W m-2) as illustrated in Figure 5.3. With such low specific stream powers it
is not unexpected to see that these river reaches plot as laterally, almost tortuously, meandering
(see Leopold and Wolman’s (1957) meandering-braiding threshold slope illustrated in Figure
5.2). As expected these rivers are characterized by fine grained sediments, plotting below the
threshold for sand-bed rivers as proposed by Kleinhans and van den Berg (2011). The sandy
nature of these floodplains is confirmed in each river reach, shown in the sediment logs in Figure
5.21. The hill-shaded map in Figure 5.20 provides evidence for the more tortuous sinuosity of
these low energy rivers and demonstrates fluvial incision indicated by steep terraces confining
each of the floodplains.
According to Nanson and Croke (1992), reaches with stream powers ˂ 10 W m-2 are
laterally stable single-channel straight/meandering floodplains, abundant in silt and clay with the
primary depositional process being overbank vertical accretion. Moreover, architectural elements
are expected to include low levees and backswamps, which are characteristic to some
81
Figure 5.20 – Low energy, lower-watershed reaches: Big Otter Creek Site 203, near Vienna, ON;
Catfish Creek Site 302, near Sparta, ON; and Ausable River Site 505, near
Springbank, ON. The hill-shaded site maps (right) illustrate the location of alluvial
terraces (hachures) and the green dots indicate the location of the cut-bank sediment
profiles and cores collected.
203
302
42°40’24” N
” N
42°42’07” N
81
°47
’12
” W
42°41’16” N
” N
42°42’07” N
81
°01
’09
” W
505
81
°38
’58
” W
43°04’32” N
” N
42°42’07” N
82
anastomosing floodplains. To confirm this accretionary style and architectural element
assemblage, a cut-bank and soil core was analyzed from site 302 and GPR was interpreted from
site 203 and 302.
For Catfish Creek site 302, the bank height exceeds 4 m from water level to the
floodplain surface in some locations, specifically the location where the cut-bank sediment
profile was collected. Further downstream where the cross-sectional survey was conducted, a
total depth from the river thalweg to the top of the floodplain surface was 3.5 m. A detailed river
cross-section was not surveyed at this location of the cut-bank due to restricted field access.
Seasonal vegetation, specifically raspberries line the perimeter of some banks ~ 1.5 m below the
floodplain surface, after which vegetation is sparse. Channels are incised by at least 1.5 m,
possibly more, at these locations.
As illustrated in Figure 5.21, the dominant accretionary style for Catfish Creek site 302 is
lateral accretion, capped by overbank fines (vertical accretion). This conforms to the expected
fining-up point-bar depositional model proposed by Miall (1992, 2010). Lateral accretion in this
bank is characterized by Sr, Sp, St and Sm lithofacies. As defined above, Sp and Sm lithofacies
are defined as linguoid and transverse dunes and flood deposits, respectively. The Sr lithofacies
for this profile are interpreted as ripples composed of sand, fine to coarse with faint laminations;
while the St lithofacies are indicative of solitary or grouped trough cross-beds, or erosional river
dunes. These lithofacies are commonly observed as downstream dipping, slightly linguoid
vertical facets. They are often composed of fine to coarse sand with some pebbles (Miall, 2010),
and this is what is observed just above the basal contact. St lithofacies are interpreted as sinuous
and linguoid 3-D dunes.
83
Vertical accretion in this bank is characterized by Fl, Fr, and P (paleosol) lithofacies. As
you can see from the profile, a stabilized surface is observed ~2.5 m below the surface. This is
characterized by an Fr lithofacies and elevated %OM. Although there is a modest increase in OM
content in this layer, %OM is generally low exceeding 3% only in the modern floodplain surface
and the P lithofacies. The P lithofacies represents a possible buried soil, which is very dark
greyish-brown (2.5YR 3/2) in colour. In other Ontario floodplain studies (Walker et al., 1997;
Stewart and Desloges, 2014) these upper most buried soils are often related to sediment inputs to
the floodplain during land clearance in the 1800’s. Cutting of softwood became an important
economic activity by late 1820 (Niewójt, 2007). Although there are no dates on the paleosol, if it
is post-settlement alluvium which suggests that alluvium above which started accumulating after
1820, then the average vertical accretion rate would be approximately 0.43 cm per year.
Basal sediments at Catfish Creek site 302 are siltier compared to the Big Otter Creek site
202 and Kettle Creek site 401. The Catfish Creek silts are very difficult to excavate, and may
represent the glacial deposit hardpans discussed in geological surveys conducted by Barnett
(1982). The basal lithofacies has been assigned the letter F, is made up of 6% clay, 50% silt, and
44% sand (very fine to very coarse); possibly representing sediments with a glaciofluvial or
glaciolacustrine origin. The Ekfid Clay Plains are present in this region (LERSPC, 2008) and
were deposited earlier than the Norfolk Sand Plains. Catfish Creek Till is also present in the
watershed and is also composed of silt and sand, however, pebbles and cobbles are also present.
The floodplain core collected 39 m from the channel bank at Catfish Creek site 202, is
illustrated in Figure 5.22. This core was extracted along the upstream end of the GPR survey line
(see Figures 5.23 and 5.27), and is representative of laterally accreted sediments accumulated on
the inner bank of an abandoned channel margin. The laterally accreted deposits are most likely
84
related to Sm, Sp, and St deposits, however, these interpretations are based on their texture only,
which is mainly fine to coarse sand. A brief pause in the floodplain development is possible
~2 m below the floodplain surface correlated with the nearby cut-bank profile. Additionally, a
very dark (7.5YR 2.5/1) thin paleosol is observed at ~1 m below the surface.
Figure 5.21 - Catfish Creek Site 302 Cut-bank Sedlog, located near Sparta, ON. Sediment was
collected just upstream on the neighbouring meander apex as illustrate by the green
dot in Figure 5.20.
85
Figure 5.22 - Catfish Creek Site 302 Sedlog, located near Sparta, ON. This profile was
constructed from sediment collected using a 5 m Environmental Soil Probe (ESP).
Compaction of sediments ranges between 0 and 13%.
86
Compaction of the soil core makes it difficult to confidently define rates of vertical
accretion from the paleosol layer. Compaction ranged from 0 – 13% across the five 1 m
floodplain cores recovered, with an average compaction value of 7%. Assuming the lithofacies at
0-0.96 m is the post-settlement alluvial surface, then a vertical accretion rate of 0.5 cm per year
would apply which is quite similar to the 0.43 cm accretion rate recorded from the cut-bank
profile upstream.
It is suspected that the basal sediments within this core reflects the bottom of an
abandoned channel located 4.5-5 m below the floodplain surface and is composed of 10% clay,
83% silt, and 2.2% OM. The silt bed is defined as an F lithofacies given the assumption that
these sediments represent Pleistocene glaciolacustrine or glaciofluvial sediments. Following the
F lithofacies are channel fill deposits (Fm and Fsm lithofacies) 3.2 to 4.1 m below the floodplain
surface and laterally accreted sands (Sp, St, and Sm lithofacies) 1.7 to 3.2 m below the floodplain
surface; capped by vertically accreted floodplain fines (Fr lithofacies) and modern flood deposits
(Sm lithofacies).
Figure 5.23 – GE image of the survey sites at Big Otter Creek Site 203, near Vienna, ON and
Catfish Creek Site 302, near Sparta, ON. The locations of each cross-section survey,
GPR survey, floodplain core, and cut-bank sediment profile are marked on each map.
81
°01
’57
” W
42°40’36” N
42°40’12” N
81
°47
’48
” W
87
Low energy, lower-watershed architectural elements are interpreted from ground-
penetrating radar collected at Big Otter Creek site 203 and Catfish Creek site 302. Two reflection
surveys were conducted at each site perpendicular to channel flow and these are illustrated in
Figures 5.24 to 5.27. Radar facies identified for these low energy floodplains include (1) lateral
accretion macroforms (LA), (2) vertically accreted floodplain fines (FF), (3) abandoned channel
floodplain fines (CH(FF), (4) a meander loop unit (CH(LA)), and (5) underlying glacial deposits
(F).
At site 203, vertical accretion is the primary architectural element of floodplain
development, illustrated by continuous, subparallel, subhorizontal reflections. These reflections
fill an abandoned channel (radar facies 3) and are linked to steep laterally accreting surfaces
(radar facies 1) approaching the channel bank. At site 302 lateral accretion and abandoned
channel accretion are the primary processes responsible for floodplain development. Figures 5.26
and 5.27 show at least two abandoned channels, illustrating a complex fill at their base and
laterally accreting sigmoid, subparallel reflections near the floodplain surface.
At each site, signal attenuation increases to 3 m below the floodplain surface for site 203
and 4.5 m for site 302. For Catfish Creek the attenuation is likely caused by the underlying silt
recovered from each of the cut-bank and core sediment profiles. At Big Otter Creek, the
attenuation may be caused by the thick sand beds observed upstream at Big Otter Creek site 202.
Unique to Catfish Creek site 302 is radar facies (4). This facies is characterized by low
angle (4-12°), modestly sigmoid-subparallel reflections dipping away from the current channel
into the floodplain. The lower boundary of this element is concave-up representing the basal
erosion surface of an abandoned channel. It is hypothesized that this opposing reflection
configuration represents the position of an older point bar formation, accreting east rather than
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west, a response to downstream river bend migration in addition to lateral migration across the
floodplain.
Figure 5.24 - GPR reflection survey collected on the apex of the meander bend at Big Otter
Creek site 203, near Vienna, ON. This profile was conducted perpendicular to flow at
the apex of the meander bend. Radar facies are indicated numerically (see Table 5.4
for codes)
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Figure 5.25 - Raw and interpreted reflection survey for ground-penetrating radar conducted
perpendicular to flow at the downstream corner of the meander bend, Big Otter
Creek site 203, near Vienna, ON. Radar facies are indicated numerically (see Table
5.4 for codes).
90
Figure 5.26 - Raw and interpreted reflection survey of ground-penetrating radar conducted
perpendicular to flow at the upstream corner of the meander bend at Catfish Creek
site 302, near Sparta, ON. Radar facies are indicated numerically (see Table 5.4 for
codes) Red line represents the location and depth of ESP core.
91
Figure 5.27 - Raw and interpreted reflection survey of ground-penetrating radar conducted
perpendicular to flow at the apex of the meander bend at Catfish Creek site 302, near
Sparta, ON. Radar facies are indicated numerically (see Table 5.4 for codes).
92
5.5 The Role of Glacial Conditioning
The characterization and classification of meandering sand-bedded rivers in southern
Ontario into three primary energy groups has provided lithological and morphological evidence
suggesting that glacial signatures may control channel morphology and processes of erosion and
deposition. The headwater reaches of Kettle and Catfish Creek are the most affected, given their
proximity to the Mount Elgin Ridges. These channels are characterized by higher stream powers,
coarser sediment and evidence of abandoned channel accretion as the dominant erosional and
depositional process responsible for floodplain development. Moreover, these reaches contain
modern mid-channel bars and back channels, characteristic of higher energy, less laterally stable
floodplains (Nanson and Croke, 1992).
The tendency to split (anabranch) is restricted to river reaches that have inherited glacial
material but lack the competence to move the excess sediment (Phillips and Desloges, 2014). To
evaluate glacial signatures in these river reaches, a suite of specific stream power energy curves
(with a power-law exponent of approximately -0.4) derived by Phillips and Desloges (2014) was
plotted on the slope-area graph (Figure 5.28). These curves represent fluvial process domains
and the potential for river reaches to develop multiple channels. The process domain concept was
proposed by Montgomery (1999) to define channel networks that are locally characterized by a
set of common geomorphic processes. As such, regions with similar geology and topography can
be mapped to summarize expected channel network responses to a disturbance.
In this study, fluvial process domains relevant to the study include moraines, outwash
sands, till plains, glaciolacutrine sand plains and glaciolacustrine clay plains. It is observed that
high and medium energy meandering river floodplains, occupying the upper and middle
watershed positions, consistently plot within the meandering river specific stream power domain
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(10-60 W m-2) and that neither of these groups of river reach types demonstrate the competence
to form multiple-channels. Nevertheless, given their respective specific stream powers, they do
show some correspondence to glacial conditioning presented by Phillips and Desloges (2014).
For the high energy reaches, specific stream powers range between 28 and 37 W m-2.
Kettle Creek site 401 and Catfish Creek site 301 are located just south of the Mount Elgin Ridges
and are characterized by sandy banks underlain by dense Catfish Creek Till. Their specific
stream powers are consistent with the values reported by Phillips and Desloges (2014) for
reaches conditioned by glacial moraines (> 30 W m-2). Medium energy river reaches reside in the
heart of the Norfolk Sand Plains and specific stream powers are between 18 and 25 W m-2. These
stream power values reflect the fluvial processes conditioned by outwash (20-60 W m-2) as
reported by Phillips and Desloges (2014). Reaches that are affected by low gradient till plains
and glaciolacustrine clay plains tend to plot well below 30 W m-2, with many under 10 W m-2
(Phillips and Desloges, 2014). These stream power values are consistent with observed specific
stream powers in the lower river reaches of the watersheds studied here (Ausable River 505,
Catfish Creek 302, and Big Otter Creek 203), which consistently plot below 5 W m-2.
To further evaluate the glacial conditioning of stream power, longitudinal profiles were
plotted against downstream changes in specific stream power for each watershed and then
compared to changing glacial landforms/deposits using published surficial geology maps.
Inherited glacial legacy effects on river slope can lead to under-steepened or over-steepened
irregularities in the long profile. These profile irregularities, in the context of the normal
concave-up, equilibrium river profile, are useful indicators of landscape diversity in southern
Ontario watersheds.
94
Figure 5.28 - Slope-area analysis for 9 river reaches surveyed in southern Ontario. Specific
stream power curves (with a power - law exponent of -0.4) were also plotted to
determine glacial legacy effects. The shaded region is representative of the
meandering river theoretical stream power domain (10-60 W m-2), based on Nanson
and Croke (1992). The boundary bolded from 60-90 W m-2 is the theoretical stream
power range for multiple channel formation.
Figures 5.29 through 5.33 show clear evidence of over-steepened and under-steepened
reaches draining into Lake Erie with associated elevated and depressed stream power values.
Elevated stream powers are observed to have a direct relationship to glacial moraines and glacial
lake strands associated with the Mount Elgin Ridges and the Horseshoe Moraines of Lake
95
Huron, while lower than expected stream powers are commonly found in the sand (outwash)
plains or glaciolacustrine clay plains.
With consideration to the graded river concept, none of these five rivers demonstrate the
ideal concave-up longitudinal profile. Instead, channel slope irregularities are visible when the
river crosses a glacial feature directly affecting fluvial processes in the reach. Moreover, the
position of more erosion resistant glacial material may lead to channel confinement, resulting in
limited lateral activity. This is evident in the head water reaches of each of Big Creek, Catfish
Creek, and Kettle Creek as they all demonstrate sinuosities of ˂ 1.5. However, where river banks
are less resistant, such as the heart of the Norfolk Sand Plains, lateral migration may be more
dynamic.
Distance from source (km)
Figure 5.29 – Big Creek longitudinal profile (black) with corresponding downstream specific
stream power curves (grey).
96
Distance from source (km)
Figure 5.30– Big Otter Creek longitudinal profile (black) with corresponding downstream
specific stream power curves (grey).
Distance from source (km)
Figure 5.31 – Catfish Creek longitudinal profile (black) with corresponding downstream specific
stream power curves (grey).
97
Distance from source (km)
Figure 5.32– Kettle Creek longitudinal profile (black) with corresponding downstream specific
stream power curves (grey).
Distance from source (km)
Figure 5.33 – Ausable River longitudinal profile (black) with corresponding downstream specific
stream power curves (grey).
98
5.6 Rates of Lateral and Vertical Accretion in the Norfolk Sand Plains
There was a remarkable absence of datable material in the sandy floodplain deposits of
this study. Another approach to understanding rates of lateral and vertical accretion is to
characterize the patterns of recent channel migration. This was done for Big Otter Creek by
mapping the historical channel positions using a sequence of georeferenced aerial photographs
and NTS maps between the period of 1909 and 1990 (Figure 5.34). The position of the channel
in 1909 is seen in blue, and 1990 is in red. There is an average channel migration rate of
approximately 0.85 meters per year over the 81 years of record (Figure 5.35). Some reaches have
very high migration rates, which are attributed to scaling error. It is interesting to observe that
selected headwater areas show little or no migration since 1909. These positions correspond to
the Mount Elgin Ridges or strands which more heavily confine the channel thereby restricting
lateral migration.
Figure 5.34 - Lateral migration of Big Otter Creek 1909-present, modified from Bijeikaite (2015)
99
Figure 5.35 – Lateral migration rate observed Big Otter Creek, ON; modified from Bijeikaite
(2015)
From the very limited radiocarbon date and thickness of post-settlement alluvium,
vertical accretion rates can also be estimated. Vertical accretion here is described as the
accumulated sand sitting on top of a datable intervals in the sediment profile. For Kettle Creek
site 401, an elk bone was extracted 1.20 m below the floodplain surface and 0.12 m above the
basal gravel lag deposit (Figure 5.6). The bone was dated to 200 ± 30 years BP. This suggests an
average accumulation of 6 mm of sand per year. At Catfish Creek paleosol layers were observed
at 0.83 m and 1.0 m below the floodplain surface for each of the cut-bank and floodplain core
profiles. Since this watershed was heavily deforested by 1820 (Niewójt, 2007), the accretion rate
for post-settlement alluvium in this reach is 4.3 mm a-1 at the cut-bank and 5 mm a-1 measured
from the core. Rates collected from the core must be taken as approximations due to challenges
with compaction.
0
100
200
300
400
500
600To
tal m
igra
tio
n (
m)
Distance from outlet (km)
Moraine
Confinement
Avg. Migration Rate = 0.85 m/yr
100
For Big Otter Creek site 202, the wood sample collected at water level, 4. 25 m below the
floodplain surface, returned a radiocarbon date of 8670 ± 30 years BP. This suggests an average
accretion of 5 mm a-1. This value is considerably lower than the accretion rates calculated above.
Moreover, this rate contradicts the rapid lateral migration rate calculated by Bijeikaite (2015) of
0.85 m per year. Thus, it is suggested here that the wood sample collected at site 202 on Big
Otter Creek may be either old material reworked into the modern floodplain, or uncovered by the
river itself as it cut into lake glacial deposits along the shore of Lake Erie.
In comparison to Walker et al. (2007) the accumulation rates reported here are quite high.
Using sediment profiles collected on the Grand River in southern Ontario, Walker et al. (2007)
determined that the average rate of vertical accretion was 0.05 – 0.07 m/century. This is
remarkably lower than the rates observed at each Catfish and Kettle Creek, which are three
orders of magnitude higher. These accumulation rates are important to this study because they
provide insight into how much sediment is being eroded and how long it is stored for (Walker et
al., 2007).
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Chapter 6: Discussion and Conclusion
6.1 Introduction
The propensity for river aggradation or degradation, and the style and rate of lateral river
channel movement, is governed by Lane’s (1955) relation of discharge and channel slope versus
sediment load and a representative material size. Rivers ideally respond to an imbalance between
these conditions by adjusting their channel platform in order to maintain equilibrium. In this
study, 9 sand-bedded river reaches (amongst five watersheds) have been divided by their slope,
sinuosity, specific stream power, and position upstream in an effort to define the primary
controls on channel morphology. The results of this study are important to current research in
southern Ontario because they provide an explanation for remarkably high sediment yields
observed in the Lake Erie basin for Big Otter Creek. Moreover, they illustrate the need for a
more thorough analysis of glacial controls on river planform morphology and rate and style of
planform development. The average annual specific sediment yield measured for 13 rivers
draining into the Lake Erie basin, between 1972 and 2005, is 62 t km-2a-1. The specific sediment
yield measured for Big Otter Creek averages 198 t km-2a-1 (Clubine et al., 2010) reflecting the
abundance of easily transported sand derived from the heart of the Norfolk Sand Plains. This
results in rapid channel migration, lateral accretion, and point bar development in middle- and
lower-reaches throughout the four sand-bedded watersheds studied here. The reaches are also
characterized by low organic matter content and anomalously tall channel banks compared to
other rivers in southern Ontario.
A detailed summary of controls on sand-bed meandering river floodplain types in the
study area is provided below. This summary is followed by a synthesis of primary processes and
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mechanisms responsible for downstream floodplain formation processes and the role of glacial
conditioning.
6.2 Summary
(1) An analysis of specific stream power versus drainage area demonstrates that 6 of the 9
studied reaches fit within the theoretical domain for meandering river floodplains (10-60
W m-2). These reaches are spilt into two primary floodplain types high energy, upper-
watershed, river reaches and medium energy, middle-watersheds, river reaches; plotting
between 28 - 37 W m-2 and 18 - 25 W m-2, respectively. The remaining 3 river low-
gradient reaches are classified as low energy, lower-watershed river reaches, plotting well
below 5 W m-2.
(2) For the most part, meandering sand-bed rivers in southern Ontario reflect laterally stable
river planforms as predicted by Leopold and Wolman (1957). Lateral instability is
confined to upper-watershed, higher energy meandering river reaches (28 - 37 W m-2),
and relate to the semi-alluvial character of their channel boundaries.
(3) Upper-watershed river reaches are characterized by slopes of 0.00078 to 0.00223 m m-1,
sinuosities ≤ 1.5, intermittent gravel on the bed, and exposures of Catfish Creek Till.
These floodplains are dominated by abandoned channel accretion (CH)FF) and vertical
accretion (FF) radar facies; which has been confirmed using GPR on the point bar surface
at Kettle Creek, site 401. CH (FF) and FF radar facies are composed of an assemblage of
Fsm, Fl, Fm or Fr lithofacies. Unique to this floodplain type, in the upper-watershed, are
hyperbolic diffractions underlying each CH(FF) and FF radar facies. An attenuated signal
is indicative of the underlying fine-grained silt material characteristic of the Catfish
103
Creek Till. The hyperbolic diffractions reflect the presence of cobble-boulders.
Therefore, at Kettle Creek site 401, a third radar facies may also define the upper-
watershed river reaches, and is described as the underlying glacial deposit (F). In this
case, the principal lithofacies assemblage for the F radar facies is Gcm/F (till and
glaciofluvial sediments).
(4) Further evidence of underlying glacial material at Kettle Creek is defined in the sediment
profile collected from the point bar. This profile illustrates a hardpan silt-clay underlying
1.3 m of gravel and vertically accreted alluvial sands. This sand cap is estimated to have
accreted at a rate of 6 mm a-1. The elevation difference between the alluvial
sedimentation zone and the water level (1.3 m) suggest that the river has incised into a
material of glaciofluvial origin. The exposure of glacial material in the lower bank and
channel bed lead to a dominance of vertical accretion which is typical of most semi-
alluvial rivers in southern Ontario (Stewart and Desloges, 2013).
(5) Middle-watershed, river reaches are characterized by slopes of 0.00053 to 0.00086 m m-1,
sinuosities between 1.6 and 1.9, and occasional outcrops of glaciolacustrine clay. These
floodplains are characterized by steeply inclined sigmoid reflections at the channel’s
edge, representing proximal lateral accretion surfaces principally composed of a St, Sp,
Sm lithofacies assemblage. Distal floodplain deposits are characterized by vertical
accretion composed of an Fsm, Fi, Fm, Fr lithofacies assemblage.
(6) Sediment profiles in middle-watershed river reaches are represented by Big Otter Creek,
site 202. This channel bank exceeds 4 meters and reflects a typical fining-upward point
bar depositional sequence. Coarse sands of possible glaciolacutirine origin are measured
at the base, followed by 1.75 m of laterally accreted sands and 1.5 m of vertically
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accreted sands. Organic material in this profile was less than 5 %, nevertheless a large
piece of wood was retrieved at water level.
(7) The age of this wood was estimated to be 8670 ± 30 years BP with two possible
explanations for its deposition. The first is that the wood is very old reworked material
inset in more modern alluvium, and the second is the sedimentation zone represents in
situ deposition of wood in an emerging landscape during the post glacial Lake Erie stages
12,000 to 7500 years BP.
(8) Lower-watershed river reaches are characterized by slopes of 0.000096 to 0.00011 m m-1,
sinuosities ≥ 2.0, and glaciolacustrine sediment lining the channel bed. These floodplains
are characterized by lateral accretion, vertical accretion, and abandoned channel accretion
floodplain formation processes. At Catfish Creek, site 302, oblique reflectors on the most
distal portion of the GPR transect, pointing away from the channel bank, are indicative to
the rapid migration of the main channel across the floodplain. Alternatively, these oblique
reflectors may represent a chute channel.
(9) The rapid migration of the main channel across the floodplain at Catfish Creek, site 302,
is also interpreted from the cut-bank sediment profile. The stacked fining-upward cycle
may suggest that the channels became superimposed on one another in an aggrading
floodplain (Stewart and Desloges, 2013).
(10) Accumulation rates for the lower-watershed Catfish Creek, site 302, were determined
using a paleosol recorded ~1.0 m below the surface and dated to ~1820 AD based on a
historical assessment of land clearance in the region. This paleosol layer suggests that the
accretion rate for the post settlement alluvium sand cap is 4.3 to 5 mm y-1.
105
(11) Lateral accretion rates for Big Otter Creek were measured using aerial photographs and
digitally corrected topographic maps. The analysis was conducted over 81 years of record
and determined that the average channel migration was 0.85 m y-1 (Biejeikaite, 2015).
This is a remarkable rate of erosion and accumulation of sand over just 81 years. Further
analysis of Beijeikaite’s (2015) dataset suggests that migration rate can be mapped
downstream and correlated to the position of glacial landforms. It is suggested that
migration rates decline in response to the position of glacial moraines, leading to channel
confinement and limited lateral activity.
(12) Longitudinal profiles of each of the studied watersheds confirm that the position of
glacial landforms has an effect on the downstream channel morphology. These
longitudinal profiles do not illustrate the classic concave-up graded river concept, instead
they show channel slope irregularities indicated by over- and under-steepened river
reaches. Over-steepened river reaches reflect stream powers indicative of the presence of
glacial moraines, whereas under steepened river reaches reflect stream powers indicative
to glaciolacustine sand or clay plains (Phillips and Desloges, 2014).
In this study, sand-bed rivers are evaluated to determine whether or not they conform to
the accepted sand-bed meandering river facies model defined by Miall (2010). It has been
determined that, for the most part, sand-bed rivers in southern Ontario do conform to the
accepted meandering river facies model proposed by Miall (2010). This is supported by an
upward-fining point bar deposition sequence, chute channels, channel fill deposits, lateral
accretion surfaces, overbank deposits, and terracing. The ridge and swale topography of most of
these floodplains is difficult to determine using satellite images, nevertheless, abandoned channel
106
accretion using the GPR conforms to the prediction of lateral channel migration and channel
reoccupation as predicted by the model. However, because the facies model is only used as a tool
for understanding how fluvial systems evolve and respond to a determined set of internal and
external controls, it is not surprising that the model does not address glacial conditioning as one
of those controls. The idealized meandering river model (e.g. Mississippi River Valley) only
accounts for fully alluvial conditions.
Quaternary sediments and landforms can have a complex effect on river channel
morphology in southern Ontario. It is observed here that the physiographic regions defined by
Chapman and Putnam (2007) have a profound effect on river channel slope and specific stream
power, sediment supply, and style and rate of vertical and lateral accretion. Moreover, it has been
observed that a single river, no matter how small, may pass through several physiographic
regions affecting the processes and mechanisms of floodplain development at the reach scale. It
has, therefore, been proposed that several fluvial process domains exist in peninsular southern
Ontario, that may help explain why some river reaches conform to the expected meandering river
facies model proposed by Miall (2010) and why others do not.
Process domains relevant to the studied river reaches include boundary materials that
consist of moraines, outwash sands, till plains, glaciolacustine sand plains and glaciolacustrine
clay plains. It has been observed that the upper-watershed river reaches of Kettle and Catfish
creeks, occupy the moraine and till plain fluvial process domains (> 30 W m-2), while middle-
watershed river reaches occupy the domain dominated by glacial outwash (20 - 60 W m-2), and
the lower-watershed river reaches occupy the domain characterized by low gradient
glaciolacutrine clay plains (< 10 W m-2).
107
To develop a more robust model of how semi-alluvial meandering rivers behave,
additional study sites are required along with a detailed accounting of vertical stability including
Holocene lake level history. Lake level history would be used to assess potential sedimentation
zone representing post glacial Lake Erie stages from 12,000 to 7500 years BP in the Norfolk
Sand Plains. The history of these lake levels would also be useful for evaluating sequential
changes to the longitudinal profiles and help to determine whether or not over- or under-
steepening regions within the glaciolacustrine sand plains conform to past Lake Erie lake levels.
The lack of organic material attests to rapid process rates in the more easily transported sand
environments, but also inhibits the establishment of strong dating control.
6.3 Future Research Considerations
Observations from this study demonstrate that there is room for further investigation of
floodplain evolution at the reach scale due to complex surface geologies. Effects of glacial
conditioning on floodplain and channel morphology are observed through anomalously tall (4
m+), irregular longitudinal profiles, and sediment profiles characterized by channel-bed hardpan
clays, occasionally overlain by coarse gravel lag desposits. Low relief glacially conditioned
catchments in southern Ontario require a revised model to incorporate the influence of
Pleistocene landforms and materials.
A future research objective is to construct a generalized facies model for meandering
river reaches in glaciated southern Ontario and classify meandering river morphologies by their
controlling glacial landform type. The proposed research questions are (i) what are the effects of
glacially conditioned stream energy and channel boundary materials to channel morphology and
floodplain development? (ii) Do reaches grouped within lithotopo units of southern Ontario
108
demonstrate distinct fluvial process domains and channel morphologies? (iii) What is the spatial
arrangement and linkage between these morphological groups? The result will be used to classify
river and floodplain morphologies by their lithotopo unit. A lithotopo unit is a conceptual
approach defined by Montgomery (1999) as regions with comparable topology and geology
where similar geomorphic processes are expected to occur. These units will help explain spatial
and temporal links between fluvial domain processes within and across watersheds.
The role of past glacial events on current channel and floodplain morphologies is central
to our understanding of channel behaviour in glaciated landscapes. By providing a tool for which
managers can use to better predict channel behaviour, modifications to the environment can be
maximized to preserve the ecological integrity of rivers.
109
References
Addy, S., Soulsby, C., and Hartley, A.J. 2014. Controls on the distribution of channel
reach morphology in selectively glaciated catchments. Geomorphology, 211, 121-133.
Allen, J.R.L. 1963. The classification of cross-stratified units, with notes on their origin.
Sedimentology, 2, 93-114.
Allen, J.R.L. 1965. A review of the origin and characteristics of recent alluvial deposits.
Sedimentology, 5, 89-191.
Annable, W. K. 1996. Database of Morphologic Characteristics of Watercourses in
Southern Ontario. Ontario Ministry of Natural Resources, Peterborough, Ontario.
Annan A.P., and Davis, J.L. 1997. Ground penetrating radar—coming of age at last. In
A.G. Gubins (Eds.), Proceedings of Exploration 97: Fourth Decennial International Conference
on Mineral Exploration. Sensors and Software, Mississauga, ON, pp. 515-522.
Annan, A.P. 2005. GPR methods for hydrogeological studies. In Y. Rubin and S.S.
Hubbard (eds.), Hydrogeophysics. Springer, Netherlands, UK, pp. 185-213.
Baker, G.S., Jordan, T.E., and Pardy, J. 2007. An introduction to ground penetrating radar
(GPR). In G.S., Baker and H.M. Jol, (Eds.), Stratigraphic Analyses Using GPR. Geological
Society of America Special Paper, 432, pp. 1-18.
Brardinoni, F., and Hassan, M.A. 2006. Glacial erosion, evolution of river long profiles
and the organization of process domains in mountain drainage basins of coastal British
Columbia. Journal of Geophysical Research, 111, F01013.
Barnett, P.J. 1982. Quaternary geology of the Tillsonburg area, southern Ontario. Report
220, Ontario Geological Survey, Sudbury, ON (87 pp.)
Barnes, A.S.L. 1967. Kettle Creek Conservation Report 1967. Department of Energy
Resources Management, Conservation Authorities Branch. Toronto, ON.
Beres, M., and Haeni, F.P. 1991. Application of Ground-Penetrating-Radar Methods in
Hydrogeological Studies. Ground Water, 29(3), 375-386.
Bijeikaite, K. 2015. What has influenced the lateral migration at Big Otter Creek,
Southern Ontario? Unpublished Honours Thesis, Department of Geography, University of
Toronto. Toronto, ON.
Blott, S.J. and Pye, K. 2001. Gradistat: a grain size distribution and statistics package for
the analysis of unconsolidated sediments. Earth Surface Process and Landforms, 26, 1237-1248.
Bridge, J.S. 1985. Paleochannel pattern inferred from alluvial deposits: a critical
evaluation. Journal of Sedimentology Petrology, 4, 579-589.
110
Bridge, J.S. 1993. Description and interpretation of fluvial deposits: a critical perspective.
Sedimentology, 40, 801-810.
Bridge, J.S., Alexander, J., Collier, R. E., Gawthorpes, R. L., and Jarvis, J. 1995. Ground
penetrating radar and coring used to study the large-scale structure of point-bar deposits in three
dimension. Sedimentology, 42, 839-852.
Bridge, J.S. 2009. Rivers and Floodplains: Forms, Processes, and Sedimentary Record.
John Wiley and Sons, New York, NY.
Brierley, G.J., and Hickin, E.J. 1992. Floodplain development based on selective
preservation of sediments, Squamish River, British Columbia. Geomorphology, 4, 381-391.
Bristow, C.S., and Jol, H.M. 2003. An introduction to ground penetrating radar (GPR) in
sediments. In C.S. Bristow and H.M. Jol (Eds.), Ground Penetrating Radar in Sediments.
Geological Society of London, Special Publications, 211, 1-7.
Brooks, G.R. 2002. Floodplain chronology and vertical sedimentation rates along the Red
River, southern Manitoba. Geographie physique et Quaternaire, 56(2-3), 171-180.
Brooks, G.R. 2003. Holocene lateral channel migration and incision of the Red River,
Manitoba, Canada. Geomorphology, 54, 197-215.
Brunsden, D., and Thornes, J.B. 1979. Landscape sensitivity and change. Transactions of
the Institute of British Geographers, New Series, 4(4), 463-484.
Chapman, L.J. and Putnam, D.F. 2007. Physiography of Southern Ontario [computer
file]. Miscellaneous Release-Data, 228, Ontario Geological Survey, Sudbury, ON.
Church, M. 2006. Bed material transport and the morphology of alluvial river channels.
Annual Review of Earth and Planetary Science, 34, 325-354.
Clubine, N.G., Desloges, J.R., and Ashmore, P. 2010. A quarter century of seasonal and
annual sediment yield variations into Lake Huron from Ausable River, Ontario [Abstract].
International Association for Great Lakes Research 53rd Annual Conference on Great Lakes
Research, May 15-19, Toronto, ON.
Dey, S. 2014. Fluvial Hydrodynamics, Geoplanet: Earth and Planetary Sciences Book
Series. Springer, New York, NY.
Dillon Consulting Ltd., and Golder Associates Ltd. 2004. Middlesex-Elgin Groundwater
Study Final Report, Project No. 02-0394, London, ON.
Dingman, S.L. 2007. Analytical derivation of at-a-station hydraulic-geometry relations.
Journal of Hydrology, 334(1-2), 17-27.
Dunne, T., and Aalto, R.E. 2013. Large River Floodplains. In Shroder, J. and Wohl, E.
(Eds.). Treaties on Geomorphology. Academic Press, San Diego, CA, 9, pp. 645-678.
111
Dust, D., and Wohl, E. 2012. Conceptual model for complex river response using an
expanded Lane`s relation. Geomorphology, 139-140, 109-121.
Environment Canada. 2015. Canadian Climate Normals 1981-2010 Station Data: St.
Thomas WPCP, Climate ID: 6137362. Meteorological Service of Canada, Downsview, ON.
Ferencevic, M.V., and Ashmore, P. 2012. Creating and evaluating digital elevation
model-based stream-power map as a stream assessment tool. River Research and Applications,
28, 1394-1416.
Ferguson, R.I. 1986. Hydraulics and hydraulic geometry. Processes in Physical
Geography, 10, 1-31.
Fola, M.E. and Rennie, C.D. 2010. Downstream hydraulic geometry of clay-dominated
cohesive bed rivers. Journal of Hydraulic Engineering, 136, 524-527.
Folk, R.I, and Ward, W.C. 1957. Brazos River bar: a study in the significance of grain
size parameters. Journal of Sedimentary Petrology, 27, 3-32.
Garaci, M.C. 1998. River terrace development of the lower Saugeen River valley,
southern Ontario. Unpublished Masters of Science dissertation, Department of Geography,
University of Toronto. Toronto, ON.
Geomorphic Solutions. 2011. East Humber River at Langstaff Road – Geomorphic
Assessment and Erosion Risk Analysis (Appendix D). In East Humber River and Langstaff Road
Rehabilitation Project. Toronto and Region Conservation Authority, Toronto, ON.
Gouw, M.J.P. 2007. Alluvial architecture of fluvial-deltaic successions: a review with
special reference to Holocene settings. Netherlands Journal of Geosciences, 86(3), 211-227.
Gouw, M.J.P., and Berendsen, H.J.A. 2007. Variability of channel-belt dimensions and
the consequences of alluvial architecture: observations from the Holocene Rhine-Meuse delta
(the Netherlands) and Lower Mississippi Valley (USA). Journal of Sedimentary Research, 77,
124-138.
Halfar, J., Riegel, W., and Walther, H. 1998. Facies architecture and sedimentology of a
meandering fluvial system: a Palaeogene example from the Weisselster Basin, Germany.
Sedimentology, 45, 1-17.
Hartman, G.M.D. and Clague, J.J. 2008. Quaternary stratigraphy and glacial history of
the Peace River valley, northeast British Columbia. Canadian Journal of Earth Science, 45, 549-
564.
Heiri, O., Lotter, A.F., and Lemcke, G. 2001. Loss on ignition as a method for estimating
organic and carbonate content in sediments: reproducibility and comparability of results. Journal
of Paleolimnology, 25, 101-110.
Henshaw, J.T. 2013. Influences of Confluences on Reach Scale Morphology of Southern
Ontario Stream Channels. Unpublished Master of Science dissertation, Department of
Geography, University of Toronto. Toronto, ON.
112
Herdendorf, C.E. 2013. Research overview: Holocene development of Lake Erie. Ohio
Journal of Science 112(2), 24-36.
Hickin, E.J. 1974. The development of meanders in natural river-channels. American
Journal of Science, 274, 414-442.
Hickin, E.J., and Nanson, G.C. 1975. The character of channel migration on the Beaton
River, northeast British Columbia, Canada. Geological Society of America Bulletin, 86, 487-
494.
Hickin, E.J., and Nanson, G.C. 1988. Lateral migration rates of river bends. Journal of
Hydraulic Engineering, ASCE, 110(11), 1557-1567.
Hickin, E.J. 1993. Fluvial facies models, a review of Canadian Research. Progress in
Physical Geography, 17(2), 205-222.
Holbrook J., Kliem, G., Nzewunwah, C., Jobe, Z., and Goble, R. 2006. Surficial
Alluvium and Topography of the Overton Bottoms North Unit, Big Muddy National Fish and
Wildlife Refuge in the Missouri River Valley and its Potential Influence on Environmental
Management. In Jacobson, R,B. (Ed.), Science to Support Adaptive Habitat Management:
Overton Bottoms North Unit, Big Muddy National Fish and Wild Life Refuge. Scientific
Investigations Report 2006-50, U.S. Geological Survey, Washington, DC, pp. 17-31.
Jackson, R.G. 1978. Preliminary evaluation of lithofacies models for meandering alluvial
streams. In Miall, A.D. (Ed.), Fluvial Sedimentology. Canadian Society of Petroleum Geologists,
Memoir 5, Calgary, AB, pp. 543-576.
Kleinhans, M.G., and van den Berg, J.H. 2011. River channel and bar patterns explained
and predicted by an empirical based method. Earth Surface Processes and Landforms, 36, 721-
738.
Knighton, A.D. 1999. Downstream variation in stream power. Geomorphology, 29, 293-
306.
Labrecque, P.A., Jensen, J.L., Hubbard, S.M., and Nielsen, H. 2011. Sedimentology and
stratigraphic architecture of a point bar deposit, Lower Cretaceous McMurray Formation
Alberta, Canada. Bulletin of Canadian Petroleum Geology, 59(2), 147-171.
Lake Erie Region Source Protection Committee 2008. Catfish Creek Characterization –
Executive Summary. Catfish Creek Conservation Authority, Aylmer, ON.
Lake Erie Region Source Protection Committee. 2014. Kettle Creek Source Protection
Area: Approved Updated Assessment Report. Kettle Creek Conservation Authority, St. Thomas,
ON.
Lane E.W. 1955. The importance of fluvial morphology in river hydraulic engineering.
American Society of Civil Engineers, Proceedings 81, 1-17.
113
Leeder, M.R. 1993. Tectonic controls upon drainage basin development, river channel
migration and alluvial architecture: implications for hydrocarbon reservoir development and
characterization. In North, C.P. and Prosser, D.J. (Eds.), Characterization of Fluvial and Aeolian
Reservoirs. Geological Society Special Publication, 73, pp. 7-22.
Leopold, L.B., and Wolman M.G. 1957. River channel patterns: braided, meandering,
straight. Geological Survey Professional Paper, 282(B), 283-300.
Leucci, G. 2012. Ground Penetrating Radar: A Useful Tool for Shallow Subsurface
Stratigraphy Characterization, Stratigraphic Analysis of Layered Deposits. In Elitok, O. (Ed.),
Stratigraphic Analysis of Layered Deposits, Intech, pp. 62-86.
Luinstra, B., Snell, L., Steele, R., Walker, M., and Veliz, M. 2008. Watershed
Characterization Ausable Bayfield Maitland Valley Source Protection Module 1(1.1). Ausable
Bayfield and Maitland Valley Conservation Authorities, Exeter, ON.
Mackin, J.H. 1948. Concept of the graded river. The Geological Society of America, 59,
463-512.
Marriott, S.B., Wright, V.P., and Williams, B.P.J. A new evaluation of fining-upward
sequences in mud-rock dominated successions of the Lower Old Red Sandstone of South Wales,
UK. In M.D. Blum, S.B. Marriott, and S. Leclair (Eds.), Fluvial Sedimentology VII.
International Association of Sedimentology Special Publications, 35, pp. 517-529.
May, R.W., Dreimans, A., and Stankowski, W. 1980. Quantitative evaluation of clast
fabrics within the Catfish Creek Till, Bradtville, Ontario. Canadian Journal of Earth Science, 17,
1064-1074.
Miall, A.D. 1985. Architectural-element analysis: a new method of facies analysis
applied to fluvial deposits. Earth Science Reviews, 22, 261-308.
Miall, A.D. 1992. Alluvial Deposits. In R.G. Walker and N.P. James (Eds.) Facies
Models: Response to Sea Level Changes. Geological Association of Canada, St. John’s, NL, pp.
47-72.
Miall, A.D. 1996. The geology of fluvial deposits: Sedimentary facies, basin analysis,
and petroleum geology. Springer-Verlag, New York, NY.
Miall, A.D. 2010. Alluvial Deposits. In J.P. Noel and R.W. Dalrymple (Eds.) Facies
Models 4. Geological Association of Canada, St. John’s, NL, pp. 105-138.
Montgomery, D.R. 1999. Process domains and the river continuum. Journal of the
American Water Resources Association, 35(2), 397-410.
Murray, M.R. 2002. Is laser particle size determination possible for carbonate-rich lake
sediments? Journal of Paleolimnology, 27, 173-183.
Nanson, G.C. 1980. Point bar and floodplain formation of the meandering Beaton River,
northeastern British Columbia, Canada. Sedimentology, 27, 3-29.
114
Nanson, G.C. 1981. New evidence of scroll-bar formation on the Beaton River.
Sedimentology, 28, 889-891.
Nanson, G.C. 1986. Episodes of vertical accretion and catastrophic stripping: a mode of
disequilibrium floodplain development. Bulletin Geological Society of America, 97, 1467-1475.
Nanson, G.C., and Croke, J.C. 1992. A genetic classification of floodplains.
Geomorphology, 4, 459-486.
Nanson, G.C., and Knigton, A.D. 1996. Anabranching rivers: their cause, character, and
classification. Earth Surface Processes and Landforms 21(3), 217-239.
Nanson, G.C., and Page, K. 1983. Lateral accretion of fine grained concave benches on
meandering rivers. Modern and Ancient Fluvial Systems, 133-143.
Nichols, G. 2009. Sedimentology and Stratigraphy, 2nd Edition. Wiley-Blackwell
Publishing, West Sussex, UK.
Niewójt, L. 2007. From waste land to Canada’s tobacco production heartland: landscape
change in Norfolk County, Ontario. Landscape Research, 32(3), 355-377.
Peterson, R.L. 1966. The mammals of eastern Canada. Oxford University Press, Toronto,
ON.
Pizzuto, J.E. 1987. Sediment diffusion during overbank flows. Sedimentology, 34, 301-
317.
Phillips, R.T.J. and Desloges, J.R. 2014. Glacially conditioned specific stream powers in
low-relief catchments of the southern Laurentian Great Lakes. Geomorphology, 206, 271-287.
Robert, A. 2003. River Processes: An introduction to fluvial dynamics. Hodder
Education, London, UK.
Rogers, E.S. and Smith, D.B. 1994. Aboriginal Ontario: Historical Perspectives on the
First Nations. Dundurn Press Ltd., Toronto, ON.
Ryzak, M. and Bieganowski, A. 2011. Methodological aspects of determining soil
particle-size distribution using the laser diffraction method. Journal of Plant Nutrition Soil
Science, 174, 624-633.
Sanford, B.V. 1969. Geology: Toronto – Windsor Area, Ontario. Geological Survey of
Canada, Department of Energy, Mines and Resources, Map 1263A.
Scumm, S.A. 1977. The Fluvial System. Wiley-Interscience, New York, NY.
Schumm, S.A. 1981. Evolution and response of the fluvial system, sedimentological
implications. The Society of Economic Paleontologists and Mineralogists, Special Publication,
31, 19-29.
115
Schumm, S.A. 1985. Patterns of alluvial rivers. Annual Review of Earth and Planetary
Sciences, 13, 5-27
Sensors and Software Inc. 2014. EKKO_Project with Processing, Bridge Deck Condition
and Pavement Structure Modules: User Guide. Mississauga, ON.
Sibul, U. 1969. Water Resources of the Big Otter Creek Drainage Basin. Ontario water
Resources Commission, Division of Water Resources, Toronto, ON.
Sinha, S.K., and Parker, G. 1996. Causes of concavity in longitudinal profiles of rivers.
Water Resources Research, 32(5), 1417-1428.
Singer, S.N., Cheng, C.K., and Scafe, M.G. 2003. The hydrogeology of southern Ontario,
2nd Edition. Environmental Monitoring and Reporting Branch, Ministry of the Environment,
Toronto, Ontario.
Smith, D.G. 1987. Meandering river point bar lithofacies models: modern and ancient
examples compares. In Ethridge, F.G., Flores, R.M. and Harvey, M.D. (Eds.), Recent
Developments in Fluvial Sedimentology. Society of Economic Paleontologists and
Mineralogists, Special Publication, 39, 83-91.
Sperazza, M., Moore, J.N., and Hendrix, M.S. 2004. High-resolution particle size
analysis of naturally occurring very fine-grained sediment through laser diffractometry. Journal
of Sedimentary Research, 74(5), 736-743.
Stewart, A.M., and Desloges, J.R. 2013. A 9000-year record of vertical and lateral
accretion on the floodplain of the lower Thames River, southwestern Ontario, Canada, and
Implications for archeological research. Quaternary International, xxx, 1-12.
Thayer, J. B. 2012. Downstream Variability of Fluvial Form, Process, and Character in a
Small Deglaciated Watershed, Southern Ontario. Unpublished Master of Science dissertation,
Department of Geography, University of Toronto. Toronto, ON.
Thornbush, M.J. 2001. Holocene floodplain development and prehistoric human
occupation: lower Nottawasaga River, southern Ontario, Canada. Unpublished Master of Science
dissertation, Department of Geography, University of Toronto. Toronto, ON.
Thornbush, M.J. and Desloges, J.R. 2011. Environmental change and evidence for
Archaic and Woodland floodplain occupation along the lower Nottawasaga River, southern
Ontario, Canada. Special Paper of the Geological Society of America, 176, 105-116.
van den Berg, J.H. 1995. Prediction of alluvial channel pattern of perennial rivers.
Geomorphology, 12, 259-279.
van Hengstum, P.J., Reinhardt, E.G., Boyce, J.I., and Clark, C. 2007. Changing
sedimentation patterns due to historical land-use change in Frenchman’s Bay, Pickering, Canada:
evidence from high-resolution textural analysis. Journal of Paleolimnology, 37, 603-618.
116
Walker, I.J., Desloges, J.R., Crawford, G.W., and Smith, D.G. 1997. Floodplain
formation processes and archeological implications at the Grand Banks site, Lower Grand River,
Southern Ontario. Geoarcheology: An International Journal, 12(8), 865-887.
Wallick, J,R., Grant, G., Lancaster, S., Bolt, J.P., Denlinger, R. 2007. Patterns and
controls on historical change in the Willamete River, Oregon USA. In A. Gupta (Ed.), Large
Rivers: Geomorphology and Management. John Wiley and Sons Ltd., pp. 491-561.
Water Survey of Canada. 2012. Historical Hydrometric Data Search. Retrieved Jan 26,
2015, from the HYDAT database. Available from: http//:www.ec.gc.ca/rhc/wsc.
Weninger, J.M. and McAndrewa, J.H. 1989. Late Holocene aggradation in the lower
Humber River valley, Toronto, Ontario. Canadian Journal of Earth Sciences, 26, 1842-1849.
Woolridge, C.L., and Hickin, E.J. 2005. Radar architecture and evolution of channel bars
in wandering gravel-bed rivers: Fraser and Squamish Rivers, British Columbia, Canada. Journal
of Sedimentary Research, 75, 844-860.
117
Appendix A: Facies, Lithofacies and Hierarchy of Facies
Table A.1 - Lithofacies common to fluvial deposits (Miall, 2010)
Facies Code Facies Sedimentary Structures Interpretation
Gmm matrix supported, massive
gravel
weak grading plastic debris flow (high-strength,
viscous)
Gms matrix supported gravel inverse to normal grading pseudoplastic debris flow (low
strength, viscous)
Gci clast-supported gravel inverse grading clast-rich debris flow (high
strength), or pseudo plastic debris
flow (low strength)
Gcm clast supported massive
gravel
pseudoplastic debris flow (inertial
bedload, turbulent flow)
Gh clast supported, crudely
bedded gravel
horizontal bedding,
imbrication
longitudinal bedforms, lag
deposits, sieve deposits
Gt gravel, stratified trough cross beds minor channel fills
Gp gravel, stratified planar cross beds transverse bedforms, deltaic
growths from older bar remnants
St sand, fine to v. coarse, may
be pebbly
solitary or grouped trough
cross beds
sinuous crested and linguoid (3-
D) (lower flow regime)
Sp sand, fine to v. coarse, may
be pebbly
solitary or grouped planar
cross beds
linguoid, transverse bars, sand
waves (2-D dunes) (lower flow
regime)
Sr sand, v. fine to coarse ripple cross-lamination ripples (lower flower regime)
Sh sand, v. fine to v. coarse,
may be pebbly
horizontal lamination parting
or streaming lineation
plane-bed flow (super-critical
flow)
Sl sand, v. fine to v. coarse,
may be pebbly
low angle (<15°) crossbeds scour fills, humpback or washed-
out dunes, antidunes
Ss sand, fine to v. coarse, may
be pebbly
broad, shallow scours scour fills
Fl sand, silt, mud massive, of faint lamination overbank, abandoned channel, or
waning flood deposit
Fsm silt, mud massive back-swamp or abandoned
channel deposits
Fm mud, silt massive, desiccation cracks overbank, abandoned channel,
drape deposits
Fr mud, silt massive, roots, bioturbation root bed, incipient soil
C coal, carbonaceous mud plant, mud films vegetated swamp deposits
P paleosol carbonate (calcite,
siderite)
pedogenic features; nodules,
filaments
soil with chemical precipitation
118
Table A.2 - Within-channel architectural elements in fluvial deposits (Miall, 2010)
Element Symbol
Principal facies
assemblage Geometry and relationships
Channels CH any combination Finger, lens or sheet; concave-up erosional
base; scale and shape highly variable; internal
concave-up 3rd order erosion surfaces common
Gravel bars and bedforms GB Gm, Gp, Gt Lens, blanket; usually tabular bodies;
commonly interbedded with SB
Sandy bedforms SB St, Sp, Sh, Sl, Sr, Se,
Ss
Lens, sheet, blanket, wedge, occurs as channel-
fills, crevasse splays, minor bars
Upstream-accretion
macroform
UA St, Sp, Sh, Sl, Sr,
Se,Ss
Lens, resting on bar remnant or LA/DA
deposit. Accretion surfaces dipping gently
upstream
Downstream-accretion
macroform
DA St, Sp,Sh, Sl, Sr, Se,
Ss
Lens resting on flat or channeled base, with
convex-up 3rd order internal erosion surfaces
and upper 4th order bounding surfaces.
Accretion surfaces oriented downstream.
Lateral-accretion
macroform
LA St, Sp, Sh, Sl, Se, Ss,
less commonly Gm,
Gt, Gp
Wedge, sheet, lobe; characterized by internal
lateral-accretion 3rd order surfaces. Accretion
surfaces oriented across channel. Typically
downlaps onto flat basal erosion surfaces
Scour hollows HO Gh, t, St, Sl Scoop-shaped hollow with asymmetric fill.
Sediment gravity flows SG Gmm. Gmg, Gci,
Gcm
Lobe, sheet, typically interbedded with GB
Laminated sand sheet LS Sh, Sl, minor Sp, Sr Sheet blanket
Table A.3 - Architectural elements of the overbank environment (Miall, 2010)
Element Symbol Lithology Geometry Interpretation
Levee LV Fl Wedge up to 10 m thick, 3
km wide
Overbank flooding
Crevasse channel CR St, Sr, Ss Ribbon up to a few hundred
m wide, 5 m deep, 10 km
long
Break in main channel
margin
Crevasse splay CS St, Sr, Fl Lens up to 10 by 10 km
across, 0.1-0.6 m thick
Delta-like progradation
from crevasse channel into
floodplain
Floodplain fines FF Fsm, Fl, Fm,
Fr
Sheet, may be many km in
lateral dimensions, up to 10s
of m thick
Deposits of overbank sheet
flow, floodplain ponds and
swamps
Abandoned channel CH(FF) Fsm, Fl, Fm,
Fr
Ribbon comparable in scale
to active channel
Product of chute or neck
cutoff
119
Table A.4 - Hierarchy of Lithofacies (Miall, 2010)
Group
Time Scale
of Processes
(yrs)
Examples of
processes
Inst.
Sedimentation
rate (m/ka)
Fluvial, deltaic
depositional units
Rank and
characteristics of
bounding surface
1 10-6 Burst-sweep
cycle
Lamina 0th order lamination
surface
2 10-5 – 10-4 Bedform
migration
105 Ripple (macroform) 1st order set bounding
surface
3 10-3 Bedform
migration
105 Diurnal/seasonal
dune increment,
reactivation surface
1st order set bouding
surfaces
4 10-2 – 10-1 Bedform
migration
104 Dune (mesoform) 2nd order co-set
bounding surface
5 100 – 101 Seasonal
events, 10-
year flood
102-3 Macroform growth
increment
3rd order dipping 5-
20°
6 102 – 103 100-year
flood, channel
and bar
migration
102-3
Macroform (e.g.
point bar, levee,
splay), immature
paleosol
4th order convex up
macroform top,
minor channel scour,
flat surface bounding
floodplain elements
7 103 – 104 Long term
geomorphic
processes
(e.g., channel
avulsion)
100 – 101
Channel, delta lobe,
mature paleosol
5th order flat to
concave-up major
channel base
8 104 – 105 5th order
Milankovich
cycles, or
response to
fault pulse
10-1
Channel belt, alluvial
fan, minor sequence
6th order sequence
boundary; flat,
regionally extensive
or base of incised
valley
9 105 – 106 4th order
Milankovich
cycles, or fault
pulse
10-1 – 10-2
Major dep. System
fan tract, sequence
7th order, sequence
boundary; flat,
regionally extensive,
or base of incised
valley
10 106 – 107 3rd order
Milankovich
cycles,
techtonic and
eustatic
processes
10-1 – 10-2
Basin-fill complex 8th order, regional
disconformity
120
Appendix B: Study Reach Characterization
Table B.1 – Bank-full channel and floodplain characteristics derived from Maximum Daily Q2-Ad Analysis
Site Characteristics Big Creek Big Otter Creek Catfish Creek Kettle Creek Ausable River
101 202 203 301 302 401 503 504 505
Drainage Area (km2) 480 659 701 350 376 357 826 854 863
% total area 83.8 93.2 99.2 88.4 94.9 83.8 69.9 72.3 73
Distance from outlet (km) 43.0 12.9 3.8 14.3 5.55 17.1 69.5 63.1 52.4
Channel Slope 0.00078 0.00053 0.00011 0.00169 0.000095 0.00223 0.00086 0.00081 0.000096
Channel Morphology
Width (m) 17.2 26.4 32.9 30.2 24.8 31.3 37.6 41.9 24.1
Depth (m) 3.35 3.40 3.62 3.09 3.50 1.95 2.81 2.96 2.78
Width:Depth 5.12 7.77 9.10 9.75 7.08 16.1 13.4 14.2 8.70
Cross-Sectional Area (m2) 57.5 89.9 119.07 93.3 86.8 60.9 13.4 124 26.9
Sinuosity 1.4 1.9 2.1 1.5 2.0 1.2 1.6 1.9 2.1
Channel Hydrology
Discharge (m3s-1) 68.8 91.9 97.2 51.6 55.1 52.6 113 116 117
Total Stream Power (W m-2) 527 473 108.4 853 51.0 1147 953 927 110
Specific Stream Power (W m-2) 30.7 17.9 3.29 28.3 2.06 36.6 25.3 22.1 4.58
Floodplain sedimentology
Overbank thickness (m) 2.20 4.28 3.89 1.65 4.28
Clay Content (%) 1.93 1.20 1.45 1.92 2.60
Silt Content (%) 28.9 18.3 15.2 19.4 17.8
Sand Content (%) 69.2 80.5 83.3 61.3 79.6
Organic Content (%) 2.29 1.12 1.14 1.57 3.16
121
Figure B.1 – Annual peak discharge (mean daily basis) across all 5 studied watersheds measured between 1942 and 2013.
122
Figure B.2 – Flood frequency distributions for five watershed gauges using annual peak flows
(mean daily basis).
y = 80.871ln(x) + 92.282
y = 26.188ln(x) + 14.657
y = 41.021ln(x) + 55.124
y = 41.142ln(x) + 37.79
y = 41.864ln(x) + 44.104
0
50
100
150
200
250
300
350
400
450
500
1 10 100
Max
imu
m D
aily
Dis
char
ge (
m3 s
-1)
Return Period, Rm (years)
Ausable@Springbank Big Creek@Walsingham
Big Otter Creek@Calton Catfish Creek@Sparta
Kettle Creek@St. Thomas Log. (Ausable@Springbank)
Log. (Big Creek@Walsingham) Log. (Big Otter Creek@Calton)
Log. (Catfish Creek@Sparta) Log. (Kettle Creek@St. Thomas)
123
Figure B.3 – Bankfull discharge (Q2) versus drainage area for river gauge and study reach sites.
0.01
0.1
1
10
100
1000
10000
1 10 100 1000 10000
Dis
char
ge, Q
2 (
m3
s-1
)
Drainage Area, Ad (km2)
Study Reaches Gauge StationsThis Study Phillips and Desloges (2014)Annable (1996)
124
Appendix C: Grain-Size Analysis
Figure C.1 – Effect of stir speed on quality of results measured using the average mean weighted
residual on select samples of a given grain-size
Figure C.2 – Effect of stir speed on the stability of grain size results measured using the D90
variation coefficient (Sperazza et al., 2004).
0.000
0.050
0.100
0.150
0.200
0.250
1000 1500 2000 2500 3000
Me
an W
eig
hte
d R
esi
du
al
Stir Speed (RPM)
Sand
Silt
Silt + Calgon
Silt + Calgon (25 s)
0.000
0.200
0.400
0.600
0.800
1.000
1.200
1.400
1.600
1000 1500 2000 2500 3000
Var
iati
on
Co
effi
cie
nt
D9
0
Stir Speed (RPM)
Sand
Silt
Silt + Calgon
Silt + Calgon (25 s)
125
Figure C.3 – Effect of measurement duration on grain size result quality using the average mean
weighted residual
Figure C.4 – Effect of measurement duration on the average mean weighted residual on
sediments collected from a vertical cut-bank profile
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0.140
0.160
0.180
10 15 20 25 30 35 40
Me
an W
eig
hte
d R
esi
du
al
Measurement Time (seconds)
Sand
Silt
Silt + Calgon
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
Ave
rage
We
igh
ted
Re
sid
ual
Sample ID
H2O2 10 sec
H2O2 30 sec
126
Figure C.5 – Stability of grain size results for cut bank profile sediments versus time of
measurement
Figure C.6 – The effect of material property selection on the Malvern 3000 on the mean average
weighted residual across cut-bank profile sediments
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14C
oef
fici
en
t o
f V
aria
tio
n
Sample ID
H2O2 30 sec
H2O2 10 sec
0.000
0.200
0.400
0.600
0.800
1.000
1.200
1.400
Ave
rage
We
igh
ted
Re
isd
ual
Sample ID
Calcite
Carbonate
Dolomite
Silica
127
Figure C.7 – The effect of material property selection on the Malvern 3000 on the mean average
weighted residual across basal sediments
0.000
0.500
1.000
1.500
2.000
2.500
3.000
3.500
10
1.1
.7
10
1.2
.11
20
2.1
.15
20
2.2
.44
20
2.3
.11
20
2.3
.12
20
3.1
.14
30
1.1
.11
30
2.1
.14
40
1.1
.7
40
1.2
.8
50
3.1
.1
50
3.2
.2
50
3.2
.2 (
2)
50
4.1
.8
50
5.2
.1
50
5.2
.2
Ave
rage
We
igh
ted
Re
sid
ual
Sample ID
Calcite
Carbonate
Dolomite
Silica
128
Table C.1 – Big Creek site 101 profile characteristics and Statistics
Sample ID % Moisture % OM
Avg. Weighted
Residual % �̅� σ Sk K
101.2.1 0.67 2.6 0.20 3.1 0.97 0.18 1.28
101.2.2 0.72 2.5 0.19 3.4 1.3 0.32 1.38
101.2.3 0.93 3.8 0.16 3.8 1.3 0.16 1.1
101.2.4 0.75 3.1 0.18 3.7 1.5 0.27 1.3
101.2.5 12 3.7 0.22 4.0 1.6 0.29 1.4
101.2.6 12 2.7 0.18 3.6 1.3 0.23 1.3
101.2.6
duplicate 0.26 3.8 1.5 0.35 1.5
101.2.7 0.33 0.88 0.18 3.2 0.93 0.15 1.1
101.2.7
duplicate 0.17 3.3 1.1 0.24 1.2
101.2.8 0.51 1.9 0.20 3.6 1.1 0.23 1.3
101.2.9 0.73 2.7 0.22 4.0 1.6 0.30 1.3
101.2.10 1.1 1.5 0.55 5.4 1.7 0.38 1.1
101.2.11 0.61 0.87 0.27 4.5 1.4 0.33 1.4
101.2.11
duplicate 0.27 4.3 1.2 0.27 1.4
Average 2.8 2.4 0.23
Table C.2 – Big Creek site 101 percentiles in phi (φ)
Sample ID φ5 φ10 φ16 φ25 φ50 φ75 φ84 φ90 φ95
101.2.1 1.8 2.1 2.3 2.5 3.1 3.7 4.0 4.4 5.4
101.2.2 1.8 2.1 2.3 2.6 3.2 4.1 4.6 5.4 6.8
101.2.3 2.0 2.3 2.6 2.9 3.7 4.6 5.1 5.5 6.4
101.2.4 1.9 2.2 2.5 2.8 3.6 4.5 5.1 5.8 7.2
101.2.5 1.9 2.3 2.6 3.0 3.8 4.7 5.4 6.5 8.0
101.2.6 1.9 2.2 2.5 2.8 3.5 4.3 4.7 5.3 6.7
101.2.6
duplicate 2.0 2.3 2.6 2.9 3.6 4.5 5.2 6.1 7.8
101.2.7 1.9 2.1 2.3 2.6 3.1 3.8 4.1 4.5 5.1
101.2.7
duplicate 1.9 2.2 2.4 2.6 3.2 3.9 4.3 4.8 5.7
101.2.8 2.2 2.5 2.7 3.0 3.7 4.3 4.7 5.1 6.4
101.2.9 2.5 2.4 2.7 3.0 3.8 4.8 5.5 6.4 7.9
101.2.10 3.4 3.7 3.9 4.2 5.0 6.3 7.3 8.2 9.1
101.2.11 2.8 3.1 3.3 3.6 4.3 5.2 5.8 6.8 8.2
101.2.11
duplicate 2.8 3.1 3.4 3.6 4.2 5.0 5.4 6.0 7.5
129
Table C.3 – Big Creek site 101 grain-size distribution using Wentworth Distribution Scale
Sample ID % Clay % Silt % vfS % fs % mS % cS % vcS
101.2.1 0.76 9.7 28 53 7.5 0.39 0.63
101.2.2 1.5 19 26 45 8.2 0 0
101.2.3 1.4 31 30 32 4.8 0.64 0.05
101.2.4 1.8 27 29 36 6.1 0.67 0
101.2.5 2.6 31 31 30 5.4 0.62 0
101.2.6 1.5 22 32 38 6.0 0.16 0
101.2.6
duplicate 2.4 26 31 36 4.5 0 0
101.2.7 0.51 12 29 51 7.3 0.01 0
101.2.7
duplicate 0.79 15 30 49 5.6 0 0
101.2.8 1.2 22 37 37 2.4 0 0
101.2.9 2.3 32 30 30 4.5 0.03 0
101.2.10 5.4 67 23 4.6 0 0 0
101.2.11 2.9 47 35 15 0.35 0 0
101.2.11
duplicate 2.1 45 38 15 0.13 0 0
Table C.4 – Big Otter Creek site 202 profile characteristics and statistics, step 1 of 4
Step Sample ID Colour %
Moisture
%
OM
Avg.
Weighted
Residual
%
�̅� σ Sk K
1
202.2.1
10YR 3/2
"very dark
grayish
brown" 8.1 2.6 0.18 3.3 1.0 0.22 1.2
202.2.2
2.5YR 3/3
"dark olive
brown" 1.2 1.5 0.23 3.2 0.81 0.15 1.1
202.2.3
10YR 3/2
"very dark
grayish
brown" 0.84 2.3 0.16 3.6 1.1 0.20 1.2
202.2.4
2.5YR 3/3
"dark olive
brown" 0.39 1.5 0.15 3.6 1.1 0.21 1.2
130
Table C.5 – Big Otter Creek site 202 profile characteristics and statistics, step 1 of 4 continued
Step Sample ID Colour %
Moisture
%
OM
Avg.
Weighted
Residual
%
�̅� σ Sk K
1
202.2.5
10YR 3/2
"very dark
grayish
brown"
0.35 1.6 0.28 4.1 1.5 0.28 1.4
202.2.6 10YR 4/3
"brown" 0.35 1.2 0.21 3.6 1.5 0.30 1.4
202.2.7 10YR 4/3
"brown" 0.16 1.2 0.15 3.4 0.99 0.13 1.1
202.2.8 10YR 4/3
"brown" 0.20 0.75 0.13 3.1 1.1 0.19 1.2
202.2.9 10YR 4/3
"brown" 0.76 1.5 0.24 4.1 1.1 0.18 1.2
202.2.10 10YR 4/3
"brown" 0.91 0.99 0.14 3.5 1.1 0.20 1.2
202.2.11 2.5YR 4/3
"olive brown" 0.15 0.35 0.18 3.0 0.98 0.21 1.2
202.2.12 10YR 4/3
"brown" 0.23 1.0 0.26 4.2 1.5 0.35 1.3
202.2.13 10YR 3/3
"dark brown" 0.56 0.92 0.25 3.5 1.6 0.31 1.3
202.2.14
10YR 3/4
"dark
yellowish
brown"
0.35 1.5 0.18 3.5 1.3 0.14 1.1
202.2.15
10YR 3/4
"dark
yellowish
brown"
0.12 0.66 0.24 2.7 0.97 0.26 1.3
202.2.16
10YR 3/4
"dark
yellowish
brown"
0.25 1.2 0.20 3.7 1.5 0.23 1.2
202.2.17
10YR 3/4
"dark
yellowish
brown"
0.18 0.77 0.30 2.4 1.0 0.32 1.5
202.2.18 2.5YR 4/3
"olive brown" 0.23 0.73 0.26 3.0 1.4 0.43 1.5
131
Table C.6 – Big Otter Creek site 202 profile characteristics and statistics, step 2 of 4
Step Sample ID Colour %
Moisture
%
OM
Avg.
Weighted
Residual
%
�̅� σ Sk K
2
202.2.19 2.5YR 4/3
"olive brown" 0.14 0.56 0.24 2.7 1.1 0.31 1.4
202.2.20
10YR 3/2 "very
dark grayish
brown" 0.35 1.7 0.28 3.3 1.6 0.47 1.3
202.2.21 10YR 4/3
"brown" 0.38 0.59 0.25 2.7 0.86 0.22 1.2
202.2.22 2.5YR 4/3
"olive brown" 0.19 0.63 0.20 3.0 0.97 0.25 1.3
202.2.23
2.5YR 3/3
"dark olive
brown" 0.25 1.1 0.23 3.6 1.6 0.34 1.4
202.2.24 2.5YR 4/3
"olive brown" 0.11 0.49 0.24 2.9 1.3 0.40 1.5
132
Table C.7 – Big Otter Creek site 202 profile characteristics and statistics, step 3 of 4
Step Sample ID Colour %
Moisture
%
OM
Avg.
Weighted
Residual
%
�̅� σ Sk K
3
202.2.25 2.5YR 4/3
"olive brown" 0.22 1.2 0.21 3.1 1.2 0.35 1.2
202.2.26 2.5YR 4/3
"olive brown" 0.71 0.86 0.20 2.9 0.93 0.23 1.2
202.2.27
10YR 3/2 "very
dark grayish
brown"
0.28 1.2 0.24 3.8 1.7 0.36 1.3
202.2.28
2.5YR 3/3
"dark olive
brown"
0.42 1.4 0.28 4.2 1.5 0.37 1.4
202.2.29
2.5YR 3/3
"dark olive
brown"
0.17 0.74 0.24 2.7 1.1 0.29 1.2
202.2.30
2.5YR 3/3
"dark olive
brown"
0.43 1.6 0.19 3.8 1.3 0.28 1.3
202.2.31 2.5YR 4/3
"olive brown" 0.15 0.72 0.14 3.1 1.2 0.27 1.2
202.2.32 10YR 4/3
"brown" 0.31 1.1 0.17 3.4 1.3 0.25 1.3
202.2.33
2.5YR 3/3
"dark olive
brown"
0.48 1.9 0.41 4.6 1.8 0.36 1.2
202.2.34
10YR 3/4 "dark
yellowish
brown"
0.20 1.1 0.29 2.8 0.92 0.27 1.4
202.2.35 2.5YR 4/3
"olive brown" 0.42 2.1 0.26 3.9 1.6 0.38 1.4
202.2.36
2.5YR 3/3
"dark olive
brown"
0.15 2.2 0.20 3.4 0.87 0.18 1.2
202.2.37 2.5YR 4/3
"olive brown" 0.070 0.73 0.31 2.7 0.98 0.30 1.4
202.2.38 2.5YR 4/3
"olive brown" 0.17 0.39 0.38 2.4 0.84 0.25 1.4
133
Table C.8 – Big Otter Creek site 202 profile characteristics and statistics, step 4 of 4
Step Sample ID Colour %
Moisture
%
OM
Avg.
Weighted
Residual
%
�̅� σ Sk K
4
202.2.39 2.5YR 4/3
"olive brown" 0.20 1.2 0.25 3.7 1.3 0.35 1.3
202.2.40
2.5YR 4/2
"dark grayish
brown" 0.15 0.79 0.21 2.9 1.1 0.31 1.4
202.2.41 10YR 3/3
"dark brown" 0.33 1.1 0.20 3.3 1.3 0.34 1.4
202.2.42
10YR 3/4
"dark
yellowish
brown" 0.12 1.6 0.21 2.7 1.1 0.32 1.4
202.2.43
2.5YR 3/3
"dark olive
brown" 4.8 0.33 0.25 3.4 1.5 0.44 1.4
202.2.44 2.5YR 4/3
"olive brown" 0.053 0.37 0.33 2.3 0.98 0.32 1.5
Table C.9 – Big Otter Creek site 202 percentiles in phi (φ), step 1 of 4
Step Sample
ID φ5 φ10 φ16 φ25 φ50 φ75 φ84 φ90 φ95
1
202.2.1 2.0 2.2 2.4 2.6 3.2 3.9 4.3 4.7 5.5
202.2.2 2.0 2.3 2.4 2.7 3.1 3.7 4.0 4.3 4.8
202.2.3 2.0 2.3 2.5 2.8 3.5 4.2 4.7 5.4 6.0
202.2.4 2.1 2.4 2.6 2.9 3.6 4.3 4.7 5.2 6.2
202.2.5 2.2 2.6 2.8 3.2 4.0 4.9 5.5 6.5 8.0
202.2.6 1.9 2.2 2.4 2.8 3.5 4.4 5.0 5.7 7.3
202.2.7 2.0 2.2 2.5 2.7 3.4 4.0 4.4 4.7 5.4
202.2.8 1.6 1.9 2.1 2.4 3.0 3.7 4.1 4.5 5.4
202.2.9 2.6 2.9 3.2 3.5 4.1 4.8 5.2 5.6 6.6
202.2.10 2.0 2.3 2.5 2.8 3.4 4.2 4.6 5.0 5.9
202.2.11 1.7 1.9 2.1 2.3 2.9 3.6 3.9 4.4 5.1
202.2.12 2.3 2.6 2.9 3.2 3.9 4.9 5.7 6.6 7.9
202.2.13 1.6 1.9 2.2 2.5 3.3 4.4 5.0 6.0 7.6
202.2.14 1.8 2.1 2.4 2.7 3.5 4.3 4.8 5.2 6.3
202.2.15 1.5 1.7 1.9 2.1 2.7 3.3 3.7 4.2 5.0
202.2.16 1.8 2.1 2.4 2.7 3.5 4.5 5.1 5.8 7.1
202.2.17 1.3 1.5 1.6 1.8 2.3 2.9 3.3 3.9 5.2
202.2.18 1.5 1.7 1.9 2.1 2.7 3.5 4.3 5.2 6.7
134
Table C.10 – Big Otter Creek site 202 percentiles in phi (φ), step 2, 3 and 4
Step Sample
ID φ5 φ10 φ16 φ25 φ50 φ75 φ84 φ90 φ95
2
202.2.19 1.5 1.7 1.9 2.1 2.6 3.3 3.7 4.3 5.5
202.2.20 1.7 1.9 2.1 2.3 3.0 4.0 4.9 5.8 7.3
202.2.21 1.6 1.8 1.9 2.2 2.6 3.2 3.5 3.8 4.7
202.2.22 1.8 2.0 2.2 2.4 2.9 3.5 3.9 4.4 5.3
202.2.23 1.8 2.1 2.4 2.7 3.4 4.4 5.1 6.1 7.6
202.2.24 1.5 1.7 1.9 2.1 2.7 3.4 4.1 5.0 6.4
3
202.2.25 1.6 1.8 2.0 2.3 2.9 3.7 4.3 5.0 6.0
202.2.26 1.7 1.9 2.0 2.3 2.8 3.4 3.7 4.1 5.0
202.2.27 1.9 2.2 2.5 2.8 3.6 4.7 5.5 6.5 7.8
202.2.28 2.4 2.7 3.0 3.2 3.9 4.9 5.7 6.6 7.9
202.2.29 1.4 1.6 1.8 2.0 2.6 3.3 3.8 4.3 5.1
202.2.30 2.2 2.5 2.8 3.0 3.7 4.5 5.1 5.8 7.0
202.2.31 1.5 1.8 2.0 2.3 3.0 3.9 4.4 4.9 5.9
202.2.32 1.8 2.1 2.3 2.6 3.3 4.1 4.6 5.1 6.5
202.2.33 2.4 2.7 3.0 3.4 4.2 5.5 6.6 7.7 8.7
202.2.34 1.6 1.8 2.0 2.2 2.7 3.3 3.6 4.0 5.1
202.2.35 2.2 2.4 2.7 3.0 3.7 4.6 5.4 6.4 8.0
202.2.36 2.2 2.4 2.6 2.8 3.3 3.9 4.2 4.5 5.2
202.2.37 1.5 1.7 1.9 2.1 2.6 3.2 3.6 4.1 5.2
202.2.38 1.4 1.6 1.7 1.9 2.4 2.9 3.1 3.5 4.6
4
202.2.39 2.1 2.4 2.6 2.8 3.5 4.4 5.0 5.7 6.9
202.2.40 1.7 1.9 2.1 2.3 2.8 3.5 3.9 4.5 5.7
202.2.41 1.8 2.0 2.2 2.5 3.1 4.0 4.5 5.3 6.9
202.2.42 1.4 1.6 1.8 2.0 2.6 3.3 3.8 4.5 5.6
202.2.43 1.8 2.0 2.2 2.5 3.1 4.1 4.9 5.9 7.5
202.2.44 1.2 1.3 1.5 1.7 2.2 2.8 3.1 3.7 5.0
135
Table C.11 – Big Otter Creek site 202 grain-size distribution using Wentworth Distribution
Scale, step 1 and 2
Step Sample
ID % Clay % Silt % vfS % fs % mS % cS % vcS
1
202.2.1 0.72 14 30 49 5.7 0 0
202.2.2 0.51 8.7 32 54 4.3 0 0
202.2.3 1.1 22 33 40 4.5 0 0
202.2.4 1.1 23 35 37 3.4 0 0
202.2.5 2.5 36 32 27 2.5 0 0
202.2.6 1.8 24 29 38 6.6 0 0
202.2.7 0.77 16 35 43 5.4 0.01 0
202.2.8 0.66 12 25 50 12 0.18 0
202.2.9 1.3 39 40 19 1.0 0 0
202.2.10 0.86 20 33 41 4.7 0 0
202.2.11 0.45 9.9 22 54 13 0 0
202.2.12 2.2 35 33 28 1.8 0 0
202.2.13 1.9 24 25 38 11 0.12 0
202.2.14 1.0 24 30 36 8.5 0.06 0
202.2.15 0.28 8.6 15 57 19 0.03 0
202.2.16 1.5 27 28 34 8.8 0.07 0
202.2.17 0.45 7.8 7.4 51 32 1.0 0
202.2.18 1.2 14 14 51 19 0.09 0
2
202.2.19 0.67 9.1 13 55 22 0.11 0
202.2.20 1.6 20 17 49 13 0 0
202.2.21 0.30 6.1 14 61 18 0 0
202.2.22 0.53 10 22 57 10 0 0
202.2.23 1.9 25 26 39 7.9 0 0
202.2.24 0.96 13 14 52 20 0 0
136
Table C.12 – Big Otter Creek site 202 grain-size distribution using Wentworth Distribution
Scale, step 3 and 4
Step Sample ID % Clay % Silt % vfS % fs % mS % cS % vcS
3
202.2.25 0.82 15 19 50 15 0 0
202.2.26 0.42 7.9 19 58 14 0 0
202.2.27 2.0 29 26 36 6.3 0.03 0
202.2.28 2.3 35 34 27 1.0 0 0
202.2.29 0.45 9.6 14 52 23 0.33 0
202.2.30 1.4 29 35 33 2.3 0 0
202.2.31 0.78 16 24 45 15 0.31 0
202.2.32 1.2 19 29 43 7.8 0.03 0
202.2.33 3.9 44 29 22 1.8 0 0
202.2.34 0.44 7.6 15 61 16 0 0
202.2.35 2.5 29 30 36 2.6 0 0
202.2.36 0.56 13 36 48 2.2 0 0
202.2.37 0.54 8.1 12 58 22 0.05 0
202.2.38 0.32 5.4 6.6 59 29 0.17 0
4
202.2.39 1.5 24 30 41 3.1 0 0
202.2.40 0.77 11 18 56 14 0 0
202.2.41 1.5 18 25 47 9.4 0 0
202.2.42 0.74 10 14 52 23 0.38 0
202.2.43 1.8 20 21 48 9.0 0 0
202.2.44 0.41 7.0 5.6 47 38 2.20 0
137
Table C.13 – Catfish Creek Site 302 Profile Characteristics and Statistics
Sample
ID Colour
%
Moisture
%
OM
Avg.
Weighted
Residual
%
�̅� σ Sk K
302.1.1
10YR 3/2
"very dark
grayish
brown"
0.59 3.9 0.18 3.2 1.3 0.32 1.1
302.1.2
10YR 4/2
"dark grayish
brown"
0.45 2.5 0.21 3.9 1.5 0.26 1.2
302.1.3 10YR 4/3
"brown" 0.19 0.87 0.31 2.8 0.96 0.30 1.4
302.1.4
2.5YR 3/2
"very dark
grayish
brown"
0.76 3.3 0.2 3.7 1.4 0.33 1.3
302.1.5 10YR 4/3
"brown" 0.42 2.0 0.17 3.4 1.3 0.26 1.3
302.1.6 10YR 4/3
"brown" 0.05 0.44 0.32 2.0 0.89 0.25 1.4
302.1.7 10YR 4/3
"brown" 1.5 0.72 0.18 2.3 1.3 0.34 1.4
302.1.7
duplicate 0.18 2.4 1.2 0.27 1.2
302.1.8 10YR 4/3
"brown" 0.04 0.34 0.39 1.7 1.0 0.35 2.1
302.1.9 10YR 4/3
"brown" 0.03 0.54 0.26 2.2 1.0 0.27 1.3
302.1.10 10YR 3/3
"dark brown" 0.13 0.91 0.28 2.1 1.1 0.32 1.5
302.1.11 10YR 4/3
"brown" 0.06 0.38 0.29 1.9 0.90 0.23 1.3
302.1.12 2.5YR 4/3
"olive brown" 0.70 0.31 0.35 1.8 0.88 0.22 1.3
302.1.13 2.5YR 4/3
"olive brown" 0.01 0.35 0.35 1.7 1.1 0.33 1.8
302.1.14 2.5YR 4/3
"olive brown" -0.02 0.47 0.28 1.9 1.5 0.45 1.6
302.1.15 10 YR 4/3
"brown" 5.1 2.4 0.49 4.6 2.5 0.07 0.98
302.1.15
duplicate 0.67 1.3 0.30 4.0 3.0 0.56 0.67
138
Table C.14 – Catfish Creek site 302 percentiles in phi (φ)
Sample ID φ5 φ10 φ16 φ25 φ50 φ75 φ84 φ90 φ95 302.1.1 1.6 1.8 2.0 2.3 3.0 4.0 4.6 5.2 6.0
302.1.2 2.0 2.3 2.6 2.9 3.7 4.7 5.3 6.0 7.4
302.1.3 1.7 1.9 2.0 2.2 2.7 3.3 3.7 4.3 5.3
302.1.4 2.1 2.3 2.6 2.8 3.5 4.5 5.1 6.0 7.3
302.1.5 1.8 2.1 2.3 2.6 3.3 4.1 4.7 5.3 6.6
302.1.6 0.9
5 1.1 1.3 1.5 2.0 2.5 2.8 3.2 4.4
302.1.7 0.8
4 1.1 1.3 1.5 2.2 3.0 3.6 4.4 5.6
302.1.7
duplicate
0.9
5 1.2 1.4 1.7 2.3 3.0 3.5 4.1 5.0
302.1.8 0.7
5 0.92 1.1 1.3 1.7 2.2 2.4 2.9 5.3
302.1.9 1.0 1.2 1.4 1.6 2.1 2.8 3.2 3.7 4.7
302.1.10 0.8
4 1.1 1.2 1.5 2.0 2.6 3.0 3.8 5.1
302.1.11 0.7
7 0.97 1.1 1.4 1.8 2.4 2.7 3.0 4.2
302.1.12 0.7
1 0.91 1.1 1.3 1.8 2.3 2.6 2.9 4.0
302.1.13 0.5
7 0.77 0.94 1.1 1.6 2.2 2.5 2.9 5.1
302.1.14 0.4
4 0.65 0.85 1.1 1.7 2.6 3.3 4.5 6.3
302.1.15 1.3 1.7 2.1 2.8 4.7 6.1 7.2 8.2 9.2
302.1.15
duplicate
0.8
3 1.1 1.3 1.6 2.8 7.0 8.0 8.8 9.7
139
Table C.15 – Catfish Creek site 301 grain-size distribution using Wentworth Distribution Scale
Sample ID % Clay % Silt % vfS % fs % mS % cS % vcS
302.1.1 0.88 18.49 19.52 45.37 15.61 0.13 0
302.1.2 1.82 31.39 28.84 32.67 5.26 0.02 0
302.1.3 0.55 9.05 15.39 60.56 14.45 0 0
302.1.4 1.61 26.31 30.17 37.72 4.2 0 0
302.1.5 1.22 19.98 28.49 41.76 8.34 0.22 0
302.1.6 0.2 4.98 3.51 40.42 44.7 6.18 0
302.1.7 0.66 9.67 8.61 37.64 35.28 8.15 0
302.1.7
duplicate 0.35 8.3 10.85 41.76 32.8 5.94 0
302.1.8 0.4 7.1 1.53 22.72 55.19 13.06 0
302.1.9 0.23 6.33 7.03 43.2 38.5 4.7 0
302.1.10 0.37 7.57 4.88 36.21 42.45 8.52 0
302.1.11 0.22 4.46 2.5 34.78 46.93 11.1 0
302.1.12 0.15 3.99 2.81 31.07 48.91 13.07 0
302.1.13 0.42 6.5 1.55 22.82 50.07 18.64 0
302.1.14 0.89 9.62 5.36 23.02 39.65 21.26 0.21
302.1.15 5.86 50.55 13.58 15.55 12.6 1.88 0
302.1.15
duplicate 8.78 34.35 3.69 15.94 28.73 8.5 0
140
Table C.16 – Catfish Creek site 302 Soil Core Profile Characteristics and Statistics
Sample ID Colour %
Moisture
%
LOI
Avg.
Weighted
Residual
%
�̅� σ Sk K
302.1.T1.L1
7.5YR 2.5/2
"very dark
brown"
10 2.0 0.27 2.9 1.7 0.47 1.3
302.1.T1.L2 7.5YR 3/2 "dark
brown" 16 2.6 0.22 3.5 1.6 0.34 1.2
302.1.T1.L3 10YR 4/3
"brown" 7.6 0.91 0.26 2.74 1.1 0.33 1.4
302.1.T2.L1 10YR 4/3
"brown" 7.7 1.2 0.23 2.9 1.2 0.35 1.3
302.1.T2.L2 7.5YR 2.5/1
"black" 9.9 2.2 0.18 3.0 1.6 0.40 1.0
302.1.T2.L3 10YR 5/3
"brown" 5.8 0.68 0.29 2.5 0.92 0.25 1.3
302.1.T3.L1 10YR 5/3
"brown" 5.7 0.72 0.29 2.5 1.1 0.32 1.5
302.1.T3.L2 10YR 3/1 "very
dark gray" 10 2.1 0.18 2.5 1.2 0.27 1.2
302.1.T3.L3 10YR 4/3
"brown" 9.6 0.78 0.30 2.6 0.99 0.30 1.5
302.1.T3.L4 10YR 4/3
"brown" 11 0.50 0.42 2.3 0.70 0.12 1.1
302.1.T4.L1 7.5YR 5/2
"brown" 8.2 0.59 0.32 2.5 0.94 0.28 1.4
302.1.T4.L2
7.5YR 2.5/3
"very dark
brown"
13 1.8 0.23 2.7 1.3 0.34 1.3
302.1.T4.L3 7.5YR 5/2
"brown" 11 0.46 0.48 1.7 0.61 0.09 1.0
302.1.T4.L4 7.5YR 3/1 "very
dark gray" 19 2.1 0.86 5.0 3.1 0.14 0.60
302.1.T4.L4
duplicate
7.5YR 3/1 "very
dark gray" 0.80 5.6 3.1 -0.21 0.60
302.1.T5.L1 7.5YR 4/2
"brown" 13 1.1 0.25 2.4 1.1 0.33 1.5
302.1.T5.L2 7.5YR 5/2
"brown" 15 0.50 0.39 1.8 0.84 0.27 1.7
302.1.T5.L3 7.5YR 4/1 "dark
gray" 16 0.99 0.35 2.0 1.5 0.49 3.0
302.1.T5.L4 7.5YR 4/1 "dark
gray" 19 2.2 0.60 6.3 1.8 0.38 0.91
141
Table C.17 – Catfish Creek site 302 soil core percentiles in phi (φ)
Sample ID φ5 φ10 φ16 φ25 φ50 φ75 φ84 φ90 φ95 302.1.T1.L1 1.1 1.3 1.5 1.80 2.5 3.7 4.8 5.8 7.1
302.1.T1.L2 1.6 1.9 2.1 2.4 3.2 4.4 5.0 5.9 7.3
302.1.T1.L3 1.4 1.6 1.8 2.0 2.6 3.2 3.7 4.4 5.5
302.1.T2.L1 1.5 1.7 1.9 2.1 2.7 3.4 4.0 4.7 5.8
302.1.T2.L2 1.0 1.3 1.5 1.8 2.6 4.0 4.9 5.5 6.3
302.1.T2.L3 1.3 1.5 1.7 1.9 2.4 3.0 3.3 3.8 4.8
302.1.T3.L1 1.3 1.5 1.7 1.9 2.4 3.0 3.4 4.1 5.4
302.1.T3.L2 1.0 1.3 1.5 1.8 2.4 3.2 3.7 4.4 5.3
302.1.T3.L3 1.5 1.7 1.9 2.1 2.5 3.1 3.5 4.1 5.3
302.1.T3.L4 1.3 1.5 1.7 1.9 2.3 2.8 3.0 3.3 3.7
302.1.T4.L1 1.4 1.6 1.8 2.0 2.5 3.0 3.4 3.9 5.0
302.1.T4.L2 1.2 1.4 1.6 1.9 2.5 3.3 3.9 4.7 5.8
302.1.T4.L3 0.79 0.96 1.1 1.3 1.7 2.1 2.3 2.5 2.8
302.1.T4.L4 1.1 1.4 1.6 1.9 4.8 7.9 8.6 9.2 10
302.1.T4.L4
duplicate 1.2 1.5 1.8 2.2 6.3 8.2 8.9 9.4 10
302.1.T5.L1 1.2 1.4 1.6 1.8 2.3 3.0 3.4 4.2 5.4
302.1.T5.L2 0.83 1.0 1.2 1.3 1.7 2.2 2.4 2.7 4.3
302.1.T5.L3 0.87 1.1 1.2 1.4 1.8 2.4 2.9 6.1 8.0
302.1.T5.L4 4.2 4.5 4.8 5.1 5.9 7.6 8.4 9.0 9.8
142
Table C.18 - Catfish Creek site 301soil core grain-size distribution using Wentworth Distribution
Scale
Sample ID % Clay % Silt % vfS % fs % mS % cS % vcS
302.1.T1.L1 1.26 18.28 10.83 37.54 28.45 3.64 0
302.1.T1.L2 1.67 24.67 21.27 39.91 12.38 0.09 0
302.1.T1.L3 0.61 10.02 12.32 52.97 23.84 0.24 0
302.1.T2.L1 0.73 12.32 14.82 51.67 20.25 0.21 0
302.1.T2.L2 0.9 20.59 11.27 36.63 25.98 4.63 0
302.1.T2.L3 0.2 6.53 9.49 55.63 27.52 0.63 0
302.1.T3.L1 0.53 8.47 8.69 51.66 29.58 1.07 0
302.1.T3.L2 0.51 9.81 11.89 44.6 28.67 4.53 0
302.1.T3.L3 0.46 8.25 11.21 57.71 22.29 0.09 0
302.1.T3.L4 0.03 3.59 5.27 58.38 32.15 0.59 0
302.1.T4.L1 0.44 7.03 9.65 56.82 25.88 0.17 0
302.1.T4.L2 0.97 11.39 12.1 45.44 27.41 2.69 0
302.1.T4.L3 0 2.73 0.72 27.1 57.71 11.74 0
302.1.T4.L4 12.44 38.81 2.24 17.87 25.64 3.01 0
302.1.T4.L4
duplicate 14.88 46.83 2.97 14.4 18.61 2.31 0
302.1.T5.L1 0.42 9.08 7.86 48.43 32.17 2.04 0
302.1.T5.L2 0.31 4.71 0.9 28.45 55.82 9.82 0
302.1.T5.L3 2.63 11.37 0.74 27.14 49.9 8.21 0
302.1.T5.L4 10.5 82.87 6.58 0.05 0 0 0
143
Table C.19 – Kettle Creek site 401 Profile Characteristics and Statistics
Sample ID Colour %
Moisture
%
LOI
Avg.
Weighted
Residual
%
�̅� σ Sk K
401.2.1 7.5YR "black"
2.5/1 2.44 5.20 0.39 4.52 2.24 0.296 0.922
401.2.2 7.5YR"very
dark grey" 3/1 1.14 2.68 0.30 3.92 2.10 0.337 1.05
401.2.3 7.5YR
"brown" 4/2 0.654 1.72 0.28 3.88 1.96 0.425 1.20
401.2.4 7.5YR "dark
brown" 3/3 1.25 1.09 0.21 2.38 1.57 0.420 1.37
401.2.5 10YR "dark
brown" 3/3 4.03 1.50 0.20 3.49 1.91 0.348 1.23
401.2.6
10YR "dark
grayish brown"
4/2
0.161 0.869 0.32 2.23 1.46 0.470 1.64
401.2.7
7.5YR,
between
brown" 4/2 and
"dark brown"
3/2
5.43 1.77 0.19 3.51 1.62 0.252 1.29
401.2.8 7.5YR
"brown" 4/2 0.127 1.27 0.30 3.38 2.11 0.508 1.11
401.2.9 7.5 YR 0.158 0.948 0.39 1.55 1.47 0.377 1.53
401.2.10 10YR "brown"
4/3 0.954 1.18 0.17 3.37 1.75 0.286 1.26
401.2.11
10YR "dark
grayish brown"
4/2
0.124 0.812 0.29 1.92 1.73 0.451 1.33
144
Table C.20 – Kettle Creek site 401 percentiles in phi (φ)
Sample ID φ5 φ10 φ16 φ25 φ50 φ75 φ84 φ90 φ95
401.2.1 1.8 2.1 2.4 2.8 4.1 6.0 7.0 7.9 8.9
401.2.2 1.4 1.73 2.0 2.4 3.5 5.2 6.2 7.2 8.4
401.2.3 1.6 1.9 2.2 2.7 3.4 4.8 6.0 7.1 8.3
401.2.4 0.68 0.92 1.1 1.4 2.1 3.1 3.9 4.9 6.5
401.2.5 1.2 1.6 1.9 2.2 3.2 4.5 5.5 6.5 7.9
401.2.6 0.76 0.96 1.1 1.4 1.9 2.8 3.6 4.7 6.3
401.2.7 1.4 1.8 2.1 2.5 3.4 4.4 5.0 5.9 7.3
401.2.8 1.2 1.4 1.6 1.9 2.7 4.5 5.8 6.9 8.2
401.2.9 -0.10 0.17 0.41 0.68 1.3 2.2 2.9 3.9 5.5
401.2.10 1.2 1.6 1.9 2.3 3.2 4.3 5.0 6.0 7.5
401.2.11 0.03 0.29 0.52 0.81 1.5 2.7 3.7 4.8 6.1
Table C.21 - Kettle Creek site 401 grain-size distribution using Wentworth Distribution Scale
Sample
ID
%
Clay
%
Silt
%
vfS
%
fs
%
mS
%
cS
%
vcS
%
Gran
%
Pebb
%
Cobb
401.2.1 4.9 42 18 27 8.3 0.04 0
401.2.2 3.2 33 18 30 14 1.3 0
401.2.3 3.0 28 21 37 10 0.50 0
401.2.4 1.0 12 9.1 30 35 12 0
401.2.5 2.3 25 19 35 16 2.9 0.002
401.2.6 0.96 11 6.4 29 42 11 0
401.2.7 1.7 24 25 36 12 1.6 0
401.2.8 2.8 24 12 33 25 2.8 0
401.2.9* 0.22 2.6 1.6 5.3 11 10 2.2 6.6 9.5 50
401.2.10
* 0.60 7.2 6.8 11 5.1 0.84 0 23 23 23
401.2.11
* 0.39 5.0 3.0 7.5 14 12 2.02 12 10 34
* %mass distributions stitched with %vol grain-sizes
145
Table C.22 – Ausable River site 504 Profile Characteristics and Statistics
Sample
ID Colour
%
Moisture
%
LOI
Avg.
Weighted
Residual �̅� σ Sk K
504.1.1 10YR
"brown" 4/3 1.21 4.22 0.00 5.76 2.44 0.04 0.83
504.1.2
10YR "dark
grayish
brown" 4/2
0.88 3.07 0.01 5.83 2.39 0.09 0.81
504.1.3 10YR
"brown" 4/3 0.75 2.33 0.01 4.83 2.35 0.32 0.88
504.1.4 10YR
"brown" 4/4 0.80 2.57 0.01 4.48 2.13 0.47 1.01
504.1.5 10YR
"brown" 4/5 3.03 3.03 0.00 6.09 2.20 0.10 0.85
504.1.5
duplicate 0.01 5.06 1.90 0.23 1.16
504.1.6 10YR
"brown" 4/5 8.95 2.95 0.00 4.48 2.15 0.33 1.04
504.1.7
10YR "dark
grayish
brown" 4/2
12.70 3.49 0.00 4.23 2.33 0.03 0.91
504.1.8
2.5YR "very
dark greyish
brown" 3/2
1.12 5.80 0.00 4.36 2.77 0.19 0.74
Table C.23 – Ausable River site 504 percentiles in phi (φ)
Sample ID φ5 φ10 φ16 φ25 φ50 φ75 φ84 φ90 φ95
504.1.1 2.17 2.68 3.18 3.87 5.73 7.59 8.36 8.98 9.74
504.1.2 2.46 2.90 3.33 3.93 5.72 7.66 8.44 9.06 9.80
504.1.3 1.92 2.28 2.61 3.04 4.33 6.44 7.54 8.37 9.27
504.1.4 2.11 2.39 2.63 2.94 3.84 5.74 6.96 8.04 9.04
504.1.5 2.91 3.41 3.84 4.40 5.97 7.73 8.45 9.06 9.79
504.1.5 duplicate 2.51 2.94 3.33 3.79 4.83 6.07 7.02 7.97 8.97
504.1.6 1.74 2.16 2.54 2.98 4.04 5.76 6.86 7.82 8.80
504.1.7 1.09 1.43 1.79 2.39 4.35 5.76 6.56 7.49 8.59
504.1.8 0.84 1.17 1.49 1.97 4.04 6.57 7.53 8.30 9.15
146
Table C.24 – Ausable River site 504 grain-size distribution using Wentworth Distribution Scale
Sample ID % Clay % Silt % vfS % fs % mS % cS % vcS
504.1.1 10.13 59.01 13.02 14.16 3.59 0.1 0
504.1.2 10.77 58.76 14.59 14.21 1.67 0 0
504.1.3 6.42 43.74 18.59 25.22 5.99 0.04 0
504.1.4 5.31 35.68 22.51 33.04 3.46 0 0
504.1.5 10.77 65.51 14.74 8.4 0.58 0 0
504.1.5
duplicate 4.99 57.83 21.35 14.39 1.45 0 0
504.1.6 4.38 39.84 22.65 25.28 7.25 0.6 0
504.1.7 3.75 46.67 13.85 16.3 15.55 3.88 0
504.1.8 5.88 41.82 8.73 17.99 18.38 7.2 0
Table C.25 - Descriptive Measures for Grain-Size Distributions, as defined by the graphic
method (Folk and Ward, 1957; Blott and Pye, 2001)
Measure Graphic Method
Median (D50) 𝜑50
Mean (�̅�) 𝜑16 + 𝜑50 + 𝜑84
3
Standard Deviation (𝜎) 𝜑84 − 𝜑16
4+
𝜑95 − 𝜑5
6.6
Skewness (Sk) 𝜑84 + 𝜑16 − 2𝜑50
2(𝜑84 − 𝜑16)+
𝜑95 + 𝜑5 − 2𝜑50
2(𝜑95 − 𝜑5)
Kutosis (K) 𝜑95 − 𝜑5
2.44(𝜑75 − 𝜑25)
147
Table C.26 – Logarithmic (original) Folk and Ward (1957) descriptive grades for sorting in phi
(Blott and Pye, 2001)
Sorting Interpretation
<0.35 very well sorted
0.35 – 0.50 well sorted
0.50 – 0.70 moderately well sorted
0.70 – 1.00 moderately sorted
1.00 – 2.00 poorly sorted
2.00 – 4.00 very poorly sorted
>4.00 extremely poorly sorted
Table C.27 - Logarithmic (original) Folk and Ward (1957) descriptive grades for skewness (Blott
and Pye, 2001)
Skewness Interpretation
+0.30 to +1.0 very fine skewed
+0.10 to +0.30 fine skewed
+0.10 to -0.1.0 symmetrical
-0.10 to -0.30 coarse skewed
-3.0 to -1.0 very coarse skewed
*skewness is a measure of the symmetry of the grain-size distribution about the mean; t has a
maximum possible value of 1 and a minimum value of -1.
Table C.28 - Logarithmic (original) Folk and Ward (1957) descriptive grades for kurtosis (Blott
and Pye, 2001)
Kurtosis Interpretation
< 0.67 very platykurtic
0.67 – 0.90 platykurtic
0.90 – 1.11 mesokurtic
1.11 – 1.50 leptokurtic
1.50 – 3.00 very leptokurtic
> 3.00 extremely leoptokurtic
*kurtosis is a measure of the degree of “peakedness”. Types of kurtosis the distribution might
display: leptokurtic (sharp peaked; K > 1), mesokurtic (normal; K = 1), and platyjurtic (flat-
peaked; K <1).
