Greg Shagam SNFFZ thesis report complete with …earthsci.fullerton.edu/parmstrong/UNDERGRAD THESES PDF...lack of ridge and ravine topography and relatively less weathering than Qf2a

Orientation of the Sierra Nevada Frontal Fault Zone near Independence and Lone Pine, California

Thesis by : Greg Shagam Advisor : Phil Armstrong Ph. D

6-19-2012

1 Orientation of the Sierra Nevada Frontal Fault Zone near Independence and Lone Pine, California

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Abstract

The western side of the Owens Valley is bound by the east-dipping normal fault

system called the Sierra Nevada Frontal Fault Zone (SNFFZ). Published

calculations of long-term horizontal extension across Owens Valley and the rest of

the western Basin and Range generally assume a relatively steep fault dip of 60

degrees. Recent studies conducted by Phillips and Majkowski (2011) along the

northern SNFFZ north of Bishop show that this boundary is better represented by

lower angle dips of 26 to 52 degrees. To test the hypothesis that faults farther south

in Owens Valley might also dip more shallowly than the assumed 60 degrees, I used

differential GPS and hand-held GPS devices to map one strand of the SNFFZ at

Independence Creek and two strands at Shepherd Creek, both west of the towns of

Independence and Lone Pine, California. GPS locations and elevations were taken

approximately every 5-10 meters along the surface exposure of the faults for up to 2

km distance in order to capture maximum elevation variation along the fault traces.

The fault orientations were determined using a program that evaluates the best-fit

fault dip of all x,y,z data points assuming a planar fault. The Independence Creek

segment has a strike of N12W and dips 29°E. The eastern Shepherd Creek stand

strikes N44W and dips 34°E, whereas the western strand strikes N40W and dips

34°E. Data collected from the hand-held GPS is compared to the differential GPS to

determine the accuracy of the hand-held device for these types of fault studies

conducted in the future. Elevation differences between the differential GPS and

handheld GPS were generally less than 10 m, but as high as 30 m. The inaccuracies

in the handheld GPS-derived elevations would potentially lead to larger


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uncertainties in average fault dip determination, but more analysis is required to

evaluate the effectiveness of using simple handheld GPS devices in these types of

studies. Because of this low-angle dip geometry, long-term horizontal extension

rates calculated from 60 degree dips need to be re-evaluated. Extension rates

determined from 60° dipping faults could be one-third the rates determined from

30° dipping faults.

Introduction Most estimates of horizontal extension rates on the Sierra Nevada Frontal Fault

Zone (SNFFZ) use an assumed normal fault dip of 60° (Le et al., 2007). Le et al.

(2007) determined the slip rates of faults in the Lone Pine and Independence areas

that facilitate the horizontal motion of this horst and graben system, but the

orientation of the actual faults have never been determined in detail. The SNFFZ is

located on the western edge of the Owens Valley where the steep face of the Sierra

Nevada Mountains rises out of the valley floor (Figure 1). North of Bishop in the

northern Owens Valley, Phillips and Majkowski (2011) found that east-facing

normal faults dip consistently less than the typically assumed 60°, with dips from

26° to 52°(Figure 2). Farther south, near Lone Pine and Independence, fault dip of

SNFFZ strands have not been documented. The goal of this study is to evaluate

fault geometry of the SNFFZ in the vicinity of Lone Pine and Independence to test

the hypothesis that these faults dip relatively shallowly.

Field reconnaissance of this area has yielded two areas with the topographic

relief needed to determine the SNFFZ fault strands. These include: (1)

Independence Creek and (2) Shepherd Creek, where the Sierra Nevada range

transitions into alluvial fan deposits of the Owens Valley (Figure 3). In these two


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areas the SNFFZ is exposed on the ground surface as mappable scarps. One scarp is

identifiable in the Independence Creek area and two scarps are identifiable in the

Shepherd Creek area; both these scarps were previously mapped by Le et al. (2007)

This information could be useful in related topics like the study of the Basin and

Range extension rates and understanding graben depression rates with low fault

angles and how they might compare to grabens with steep fault angles.

A side objective to this study will be the comparison in accuracy of a Garmin

hand-held GPS to a differential GPS system unit with regards to UTM northings,

eastings and elevation. Can fault studies of this scale be accurately conducted in the

future using light-weight hand-held GPS devices instead of costly and bulky

differential GPS equipment? What would be the compromise in accuracy, if any, in

choosing the hand-held GPS solely to conduct future fault studies?

Geologic Background The Owens Valley is structurally complex and currently active as evidenced by

the 1872 Lone Pine Earthquake. The stress regime is partitioned at the surface into

strike-slip motion on the Owens Valley and Lone Pine faults and dip-slip for the

SNFFZ. Assumptions have been made on how these two faults interact at depth

(Phillips and Majkowski, 2011), but no definitive conclusions have been made.

Tectonically this area is driven by the stress imparted by the translational

movement between the North American plate and the Pacific plate boundary

regionally defined by the San Andreas Fault. This stress contributes to the

migration of what some call the Sierra Nevada Micro-plate in the generalized

azimuth of 331 degrees (Unruh and Barren, 2003). During the Mesozoic, an


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ancient mountain range spanned the western coast due to the compressional forces

of subduction occurring just off the North American coast (Sevier Orogeny). Due to

this subduction, granitic plutons intruded the overriding plate to form to roots of

the Sierra Nevada Mountain range. The subduction of the Mendocino triple

junction, approximately 5 Ma, altered the stress components in this region to a

translational movement that defines the San Andreas Fault (Hill, 2006).

Due to the stress imparted by the oblique motion of the Pacific plate relative to

the Sierra Nevada micro-plate and the North American plate, the Owens Valley and

the surrounding area are complexly fractured and faulted. To the east of the Sierra

Nevada Province, Owens Valley marks the western extend of the Basin and Range

Province. Major Faulting has occurred in the Owens Valley along the Lone Pine

Fault, the Owens Valley Fault, the SNFFZ, the White Mountains Fault and many

other minor related faults.

The SNFFZ extends approximately 600 km from just north of the Garlock fault

all the way north to the Cascade Range. Along this distance the SNFFZ trends NW

with slightly varying strikes and exhibiting dextral en echelon escarpments to well

defined single escarpments. The faults of the SNFFZ offset granitic basement rocks

of the Sierra Nevada and Quaternary fan deposits of Owens Valley (Le et al., 2007).

Figures 3 and 4 show the varying Quaternary deposits in my field area as mapped by

Le et al., (2007).

Quaternary deposits of Owens Valley Surficial deposits found in this area are largely comprised of alluvial fan

deposits of varying age from 124 ka to 3-4 ka (Le et al., 2007). Cause for


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deposition of these alluvial fans varies from glacial and non-glacial giving the

deposits a number of different geomorphic characteristics. Because of varying

deposit types, Le et al. (2007) chose to differentiate the fans observed in Owens

Valley just east of the SNFFZ with seven sub-classifications, not including

landslide deposits. Quartz-rich boulder samples were collected from the deposits

for model CRN Beryllium-10 exposure age dating and recalculated using an

erosion rate of 0.3 cm/k.y. of the boulder surface (Small et al.,1995) These

deposits are all Quaternary in age with the oldest, Qf1 occurring approximately

123.7+/- 16.6 ka. Qf4 is the youngest and currently active channels are dated

approximately 3-4 ka. Using the descriptions given by Le et al. (2007), the alluvial

deposits are identified below. Geophysical data suggest that the area between the

Alabama hills and the Sierra Nevada Range it is underlain with approximately 100

m thick of alluvial deposits (Phillips & Majkowski, 2011). The following

descriptions are based on Le et al. (2007).

Qf1 Localities exhibiting Qf1 fan deposits are limited. Typically these deposits are

orange to orange tan in aerial photos and appear as mounds approximately 30-100

meters high. These varnished, highly dissected, strongly weathered-elephant skin

boulder deposits consist typically of granitic fragments of rounded to sub-rounded

clasts bi-modally distributed into cobbles and pebbles with a grus and sand matrix.

Qf2 Qf2 is farther sub-divided into Qf2a and Qf2b. The older of the two is the Qf2a

deposit, and it is characterized by a ridge and ravine topographic profile ranging

from a few meters to tens of meters. This deposit appears in aerial photos as

typically yellow or yellow-tan and is best identified by their lack of boulders. These


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deposits can also be underlain by unconsolidated fan deposits comprised

weathered, angular to sub-angular grus. The Qf2b deposits are inset and inter-

tongued with Qf2a and exhibit similar features. What separates the Qf2b is their

lack of ridge and ravine topography and relatively less weathering than Qf2a. The

mean Be-10 model age calculated for this deposit is 60.9+/-6.6 ka.

Qf3 The area covered by Qf3 is much larger than all other fans. Because of this Qf3

is further sub-divided into 3 divisions; Qf3a, Qf3b, and Qf3c. The oldest being Qf3a

and the youngest is Qf3c. Qf3a is characterized by yellow-tan to tan-white in aerial

photographs, planar, densely vegetated and exhibit weakly developed desert

varnish. A grus matrix of fine grained granitic clasts host very few boulders. Be-10

dating of Qf3a deposits gives a mean model age of 25.8 +/- 7.5 ka. Qf3b fans extend

farther than any other fan, up to 11 km from the range front. A muted bar and swale

morphology can be distinguished in these fans and they can be inset into Qf3a fans.

Dendritic channel networks ranging from 1-2.5 m deep that include granitic

boulders are also typical of Qf3b (Le et al., 2007;). Qf3b surfaces are typically

covered with boulders averaging 1-3 m high. Clasts can be sub-angular to sub-

rounded granitic boulders, pebbles and cobbles in a coarse-grained sandy matrix.

Qf3c is the youngest and extends roughly 2 to 4 km from the range front. These

deposits exhibit a well preserved bar and swale morphology. The surfaces are un-

dissected, un-varnished and hummocky. The surface also contains many boulder

lined channels with clasts ranging in size from 1-9m high. These large boulders

constitute approximately 20+% of the fan and indicate towards a glacial outflow.

Samples collected of Qf3c indicated a mean exposure age of 4.4 +/- 1.1 ka.


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Qf4 This deposit is the youngest and cross-cut all other older fans. Active and

recently abandoned channels are present and contain debris-flow including trees

and vegetation. These deposits can be densely vegetated and typically are

unvarnished. Samples collected of Qf4 indicate a mean exposure age of

approximately 4.1+/- 1.0 ka.

Qls North of Independence creek, along the range front exists a rockslide of

approximately 1000 m2. This deposit is typical of a slide and exhibits hummocky

morphology. Clasts are very angular, clast supported with no matrix. Exposure

dating of these rocks indicates that this slide occurred approximately 18.7 +/- 3.9

ka.

Qm Glacial deposits have been identified along the eastern flank of the Sierra

Nevada (Le et al., 2007; Gillespie, 1982; Bierman et al., 1995). Exposure ages for

these deposits correlate within error to the estimated glacial periods of the Tioga,

Tenaya, Tahoe/younger Tahoe, and Mono Basin. These deposits exist as moraines

found near the Onion Creek area and form narrow, elongated lobes of glacially

transported sediment overlain by approximately 1-8 m high granitic boulders along

the crest. The exception to the glacially affected deposits are the Qf3c and the Qf4

deposits which still exhibit levee boulder bars, more indicating debris-flows rather

than glacial deposition.


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Faults

Eastern Boundary-‐Sierra Nevada Frontal Fault Zone The boundary between the Sierra Nevada and the Basin and Range provinces forms a

complex fault system that includes the Sierra Nevada Frontal Fault Zone, the Owens Valley

fault and the Lone Pine faults. Along the range front, the SNFFZ typically exhibits only

normal, dip-slip faulting (Le et al., 2007). The Owens Valley and Lone Pine faults exhibit

dextral strike slip and oblique slip, respectively. The Owens Valley Fault is parallel to sub-

parallel with the SNFFZ and is located a few kilometers to the east (Figure 1 & 3). The Lone

pine Fault is located approximately 3-5 kilometers east of the range front and just south of

the Owens Valley fault (Figure 1). These three faults facilitate both extension and dextral

motion along the boundary of the Sierra Nevada and the Basin and Range provinces.

Le et al. (2007) conducted detailed studies of an area covering a 35 km long and 5 km

wide section between Oak Creek and Lubkin creek of the SNFFZ (Figure 3). The strike of

this fault system ranges from approximately 350 to 310 degrees, with an average for the

system approximately 334 degrees. These faults typically dip to the east, but a few west

dipping faults are present. In the hanging wall, Quaternary sediment is usually found next

to granite or other Quaternary sediment. Of all the above listed Quaternary deposits, Q4 is

the only deposit not faulted in this region. All other Quaternary deposits exhibit offset

along the SNFFZ faults. These faults are right-stepping, en echelon, NW striking, assumed

to dip around 60 degrees to the east, and display only dip-slip motion.

Moderately degraded and semi-vegetated fault scarps yield vertical offset measurements

ranging from 41.0 +/-2.0 m to 2.0 +/-0.1 m (Le et al., 2007). Combined with CRN Be-10

age dating, vertical slip rate estimates of 0.2-0.3+/-0.1 mm/yr since ca. 124 ka., 0.2-0.4 +/-

0.1 mm/yr since ca. 61 ka, 0.3-0.4 +/- 0.2 mm/yr since ca. 26 ka, and 1.6 +/- 0.4 mm/yr

since ca. 4 ka. Le et al., (2007) also calculated extension rates, assuming a 60 degree

normal fault dip, range from 0.1-0.2 +/- 0.1 mm/yr to 0.9 +/- 0.4 mm/yr. Offset found


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near San Joaquin river is on the scale of approximately 980 meters, which implies a long

term vertical slip rate of 0.3-0.4 mm/yr (Wakabayashi & Sawyer, 2001). The Le et al.

(2007) results suggest that the rigid Sierra Nevada “micro-plate” has a late Pleistocene to

recent rate of 3.0 mm/yr, at 331 degrees (azimuth) relative to a stationary marker east of

the Basin and Range province.

Southern and northeastern boundary Bounding the south-eastern side of the Sierra Nevada, the Little Lake and Airport

Lake faults display dextral motion and have helped to form the Indian Wells valley

(Le et al., 2007). These faults transfer their slip over to the Owens Valley where

more parallel faults can relieve accumulated stress more effectively in a dextral-

normal slip (Phillips & Majkowski, 2011). Sub-parallel dextral, strike-slip faults in

Mohawk Valley to the north also relieve the trans-rotational forces formed by the

rotation of the Sierra Nevada (Le et al., 2007). Also according to Le, Holocene slip

rates of the Owens Valley are on the order of 1.8 – 3.6 mm/yr with an earthquake

reoccurrence interval of 3000 to 4000 years. Paleosiesmic slip rates are

approximately 3.3-3.8 mm/yr for the Owens valley fault. The dynamics of this

region are similar to that of a horst and graben with the Sierra Nevada Mountain

range and the Inyo mountains representing the horst features and the Owens Valley

in between is the graben.

Methods

Mapping Establishing a suitable field area consisted of field reconnaissance and field

mapping of fault scarps where incision by local creeks provided sufficient relief for

regional fault dip analysis. Three strands of the SNFFZ were identified and chosen


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as sufficient locales (Figures 4 & 5). The faults were mapped on 7.5 minute USGS

topographic maps and on Google Earth images. At each strand the scarp was

walked out and x,y,z position coordinates were recorded at each station using two

devices: (1) Topcon GB-1000 differential GPS system and (2) Garmin Oregon 550

hand-held GPS device.

Set-up of the Topcon GB-1000 differential GPS system can be a complicated and

timely. Two receivers are required for the differential GPS system as seen in figure

14. After the tripods are set up and the devices are powered up there is an

initialization period. During the initialization phase of setting up the differential

GPS, the device needs to be left for a minimum of 30- 45 minutes. During this time

the base station almanacs its stationary position so that accurate corrections can be

made to correct the rover during the survey. Once the initialization process is

complete the system is ready for the survey to begin.

The set-up is much less complicated for the Garmin hand-held device. Charged

batteries will be required for the hand-held GPS to work as well as it is designed to.

Powering up the device only takes a few minutes and selecting the appropriate

datum is the only real step required to set-up the Garmin hand-held device. The

datum used during this survey is WGS84.

After all the devices are running, the survey begins by locating the fault scarp to

be analyzed and walking to one end of the strand. Starting with the Topcon device

the rover pole is positioned at the transition from the scarp to the hanging wall of

the fault (Figure 7). For this type of study I chose a 30 sec data acquiring interval.

This means that over the 30 seconds the device is acquiring data, the Topcon device


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will take 6 – five second readings and average them out to produce a mean final

x,y,z reading at that locale. This process continues for every station chosen for the

survey.

Acquiring x,y,z coordinates from the Garmin hand-held device only takes a few

seconds and is logged while the Topcon differential is running. The hand-held

device is held approximately 1 m away (waist level and 0.5 m perpendicularly away

from the Topcon receiver pole) from the Topcon receiver at the top of the pole.

After the data cataloged for both devices, I continued tracing and following the

fault line at the surface at approximately 10-15 m intervals. The process of acquiring

data on both devices would be repeated and so on. In the Independence Creek area

40 stations were located (figures 5 & 8). In the Shepherd Creek east and west study

areas, 35 and 40 stations were located respectively (figures 6,7,9,10).

Data post-‐processing For both devices the data is required to be post-processed to be usable. Post

processing for the Topcon system is not the same as for the Garmin device. The raw

Topcon data were post-processed using the Topcon Tools software suite. Raw

hand-held data were post-processed using Garmin software, Google Earth and DEM

publications. During post-processing corrections and static adjustments can be

made to better correlate data.

Post-processing of the Garmin hand-held data consisted of correlating

elevations from DEM publications. The easting and northing points acquired in the

field from the Garmin were used to determine the DEM elevations for the same


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easting and northings. The elevations used in the x,y,z comparisons were

determined using the DEM elevations.

Post-processing for the Topcon Device requires that a reliable base station be

determined. All corrections made to the rover will be with respect to the base

station. For Independence Creek the base station is located on figure 8 at the

station labeled base 1. For the Shepherd Creek area study the base station was

modified to a permanent base station (CORS station #p467) locate in the Alabama

Hills about 23 km to the southeast.

In order to correct the GPS derived elevations to the local elevations on USGS

1:24,000 topographic maps, static elevation corrections for each site were made to

the raw data. For the Independence area, the elevation correction was 33 meters.

Because of this, 33 meters was added to all raw elevation readings at Independence

Creek. For the Shepherd Creek area, the correction was 28 meters. To correct for

this 28 meters was added to all raw elevation readings in the Shepherd Creek area.

The post-processed and elevation-corrected x,y,z data from the Topcon

differential GPS survey from each of the three fault strand surveys were analyzed to

determine best-fit strike and dip using a simple spreadsheet program (Fred Phillips,

personal communication)(figures 24-29). The inputs for this program are the x, y,

and z components of survey points along a fault. The program allows the user to

manipulate the strike-parallel line to get the most accurate dip calculation. After

the strike has been narrowed down to within a few degrees it can be shifted to find

the greatest R2 value to a trend line directly related to the faults dip. After the strike

is determined to optimize the R2 value, assuming a planar fault, the dip of the fault


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can be calculated. To calculate the dip of the fault taking the inverse tangent

function of the slope created by that trend line will give the fault dip angle.

Results

Comparison of Topcon and Garmin data Data from the Garmin hand-held device and the Topcon Differential system

were compared to get a sense of the accuracy of the hand-held device. Because the

data for stations collected on both devices were taken at essentially the same

location (within a 1-2 meters), the northing, easting, and elevations should be the

same. The Differential system is much more reliable and if all set-up procedures are

correctly executed then the error range is fairly small (less than a meter). Graphical

analysis of this data can give us an indication of how close the Garmin data is to the

Differential systems readings. For each strand of the SNFFZ surveyed, elevations

were compared to elevations, eastings were compared to eastings, and northings

were compared to northings.

The Independence Creek area, like the other two strands surveyed, will have the

data from each station tabulated and the three graphs generated by the elevation,

easting, and northing comparisons. The elevation graph (figure 15) shows that the

hand-held device consistently produced elevations higher than the Topcon by 5 to

20 meters. A trend line of the scatter data would run almost parallel to the red 1:1

line and might be correctable with a more accurate base station elevation. For this

study area, error in elevation readings could be as much as 20 m.

The Independence Creek easting and northings correlate more accurately than

the elevation data. The greatest difference between the two devices is 6 meters with

an average difference of roughly 3-4 meters. The trend lines created by the easting


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and nothing plots (figures 16 and 17 respectively) have a slope almost exactly one

and R2 values of almost exactly 1.000.

The Shepherd Creek east elevation plot (figure 18) shows the Garmin hand-held

device data, on average, more closely resembles the 1:1 line in red. Max difference

error for this strand in elevation is up to 22 meters. The easting and northing plots

(figures 19 and 20), like all three areas studied, yield R2 and slopes for the data

trend lines that almost equal to 1. For the easting and northing greatest max

difference in readings are 4 m and 18 m, respectively.

The Shepherd Creek west elevation plot (figure 21) shows the Garmin hand-held

device data, on average, almost matches the 1:1 line (in red). Max difference error

for this strand in elevation is up to 17 meters. The easting and northing plots

(figures 22 and 23), yield R2 and slopes for the data trend lines that almost equal

exactly 1. For the easting and northing greatest max difference in readings are 6 m

and 9 m respectively.

Fault Orientations The main purpose of this study is to determine the dip angle of the SNFFZ in

this area. Using the Excel spreadsheet program supplied by Professor Fred Phillips

(F. Phillips, Personal Communication), a plot of the easting and northing data yields

a best-fit strike line. Directly correlated to that plot is another plot that uses the

strike to determine the dip of the fault. To determine the dip of the fault in degrees

it is required the equation for the trend line in the second plot is displayed. With

that equation (y=mx+b), taking the inverse-tangent function of the slope (“m”)

value will provide the fault dip in degrees. These two plots are the output of the

Excel spreadsheet program and give us the strike and dip of each SNFFZ strand

studied.


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The Independence Creek strand strikes azimuth 348 degrees or N 12 W (figure

24) and dips 29 degrees east (figure 25). The Shepherd Creek east strand strikes

azimuth 316 degrees or N 44 W (figure 26) and dips 34 degrees east (figure 27). The

Shepherd Creek west strand strikes azimuth 320 degrees or N 40 W (figure 26) and

dips 34 degrees east (figure 27).

Discussion The implications of this study directly relate to the calculated horizontal-

extension rates of the Owens Valley, and possibly even the Basin and Range

province. Previously published rates on this matter are underestimated if a 60

degree-dipping fault angle was assumed. Quantitatively determining how much the

extension rates are underestimated is more difficult to do. Geometry of the White

Mountains fault on the other side of the valley, a west-facing, normal-slip fault

defining the other half of the grabben, is also required. An underestimation of at

least a third is plausible with making no assumptions to the geometry of the White

Mountain Fault. If the other side of the grabben were found to best be defined by

low-angle normal faulting that number could double. Extrapolating fault dip angles

that are too steep across the entire Basin and Range province could lead to serious

implications about the long-term extension rates. If all the faults that are presently

assumed to dip 60 degrees really dip 30-35 degrees as determined from the three

faults studied in this project, overall, long-term extension rates could be

underestimated by a factor of about three.

The Differential GPS data was used in Fred Phillips Program to determine the

orientation because the data collected from this system is proven accurate. Given


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the relatively low difference in the data from the two devices, I would say that the

Garmin Oregon 550 hand-held GPS is accurate enough to conduct a study like this

with the intent to determine a high-angle versus a low-angle fault characteristic.

However, a more thorough analysis would need to be completed to evaluate the

future potential of foregoing the more accurate differential GPS system and using

hand-held devices (such as the Garmin hand-held used in this study).

Conclusions The orientations of the three strands of the SNFFZ at Independence Creek and

Shepherd Creek were determined. In the Independence Creek area, the section of

the SNFFZ studied strikes N12W and dips 29 degrees east. In the Shepherd Creek

field area two strands of the SNFFZ were studied. The east strand in the Shepherd

Creek area strikes N44W and dips 34 degrees east. The west strand strikes N40W

and dips 34 degrees east. All three strands of the SNFFZ studied are 1-2 km long

fault exposures of a much more extensive fault system that spans hundreds of km.

In order to fully understand the dip of the SNFFZ along its entirety, more studies

that continue the work of this study, and the work of Phillips and Majkowski (2011),

need to be completed.


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References Argus, D.F., Gordon, R.G., 1991, Current Sierra Nevada-North America motion from very long baseline interferometry: Implications for the kinematics of the western United States, Geology, v. 19; no. 11; p. 1085-1088

Bierman, P.R., Gillespie, A.R., and Caffee, M.W., 1995, Cosmogenic ages for recurrence intervals and debris flow fan deposition, Owens Valley, California: Science, v. 270, P. 447-450

Gillespie, A.R., 1982, Quaternary glaciation and tectonism in the southern Sierra Nevada, Inyo County, California (PH.D. thesis); Pasadena, California Institute of Technology, p. 736

Henry, C.D., 2009, Uplift of the Sierra Nevada, California, Geology, vol 37, p 575-576

Hill, M., 2006, Geology of the Sierra Nevada: Revised Edition (California Natural History Guides), May 15, 2006

Le, K., Lee, J., Owen, L.A., Finkel, R., 2007, Late Quaternary slip rates along the Sierra Nevada frontal fault zone, California: Slip partitioning across the western margin of the eastern California shear zone-Basin and Range Province, Geological Society of America Bulletin, v. 119, p 240-256

Phillips, F. M., Majkowski, L., 2011, The role of low-angle normal faulting in active tectonics of the northern Owens Valley, California, Lithosphere, v.3, p. 22 - 36

Sauber, J., Thatcher,W., Solomon, S.C., Lisowski, M., 1994, Geodetic slip rate for the eastern California shear zone and the recurrence time of Mojave desert earthquakes, Nature Publishing Group, Nature 367, p 264 - 266

Small, E.E., Anderson, R.S., 1995, Geomorphically driven late Cenozoic rock uplift in the Sierra Nevada, California: science, v. 270, p 277-281

Unruh, J., Barren, A., 2003, Transtensional model for the Sierra Nevada frontal fault system, eastern California, Geology; April 2003; v. 3, p. 327-330

Wakabayashi, J., Sawyer, T.L., 2001, Stream Incision, Tectonics, Uplift, and Evolution of Topography of the Sierra Nevada, California, The Journal of Geology, v. 109, No. 5, p. 539-562


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Figures and Tables


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List of Figure Captions

Figure 1. Shaded relief map showing the location of the general study area (inside

dashed box) and its relation to the faults of the part of the Eastern California Shear

Zone. Balls on faults are on hanging-wall side of normal faults. Strike-slip faults

have arrow showing relative offset direction. The study area is bound on west by

the Sierra Nevada and on the east by Owens Valley. Map modified from Le et al.

(2007).

Figure 2- Shaded relief map and Bathemetric plot of Fault orientations and

sediment depths in the northern Owens Valley. Biship, California is located near

the center of the image. The mountain range to the northe east of Bishop is the

White Mountains. The mountain range to the south west is the Sierra Nevada

Mountains. The yellow arrows with black numbers indicate the direction and the

dip of the faults studied in that area. The various colors on the valley floor indicate

sediment depth. Map modified from Phillips and Majkowski, (2011).

Figure 3- Geologic map of SNFFZ and the Owens Valley showing Quaternary

deposits (Le et al., 2007). This map shows fault scarps of the SNFFZ trending

northwest with en echelon dextral steps. These quaternary deposits are offset due

to the normal faulting of the SNFFZ. The creeks that cross the SNFFZ are shown.

Map modified from Le et al. (2007).

Figure 4- Simplified geologic map of Quaternary fan deposits offset by the SNFFZ in

the Shepherd Creek Area. Fault scarps are depicted as lines with hachures on the


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downthrown side. Mean Cosmogenic age dates for most of the differentiated

Quaternary deposits found in the vicinity are located to the right of the image. Map

and tables modified from Le et al. (2007).

Figure 5- Topographic map taken from the USGS Kearsarge Peak Quadrangle 7.5-

minute series showing the Onion Valley road as it crosses the SNFFZ in the vicinity

of the Independence Creek. The small red dots indicate data points where x,y,z

coordinates were taken by the Garmin hand-held device as the fault scarp was

walked out.

Figure 6 - Topographic map of the Shepherd Creek area taken from the USGS Mt.

Williamson Quadrangle 7.5- minute series showing the transition from mountains

to fan deposits in the northwestern direction. The red and blue dots indicate data

points where x,y,z coordinates were taken by the Garmin hand-held device as the

fault scarp was walked out.

Figure 7 - Schematic diagram illustrating where fault GPS locations were made.

Rover pole was placed at intersection of degraded fault scarp and hanging-wall

deposits.

Figure 8- Google earth image depicting the 40 data points collected by the Topcon

CB-1000 differential GPS system from the Independence Creek study area. Data

points of equal elevations have black lines connecting the two. The strike of that

line determines the strike of the fault for that section.

Figure 9- Google Earth image depicting the 35 data points collected by the Topcon

GB-1000 differential GPS system from the Shepherd Creek study area. These data

are taken from the east strand of the two Shepherd Creek strands of the SNFFZ.


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Data points of equal elevations have black lines connecting the two. The strike of

that line determines the strike of the fault for that section.

Figure 10- Google earth image depicting the 40 data points collected by the Topcon

GB-1000 differential GPS system from the Shepherd Creek study area. These data

are taken from the west strand of the two Shepherd Creek strands of the SNFFZ.

Data points of equal elevations have black lines connecting the two. The strike of

that line determines the strike of the fault for that section.

Figure 11- This picture was taken toward the south during field work in the

Shepherd Creek area. It shows the east and west strand on the south side of the

Shepherd Creek channel.

Figure 12- This picture was taken while conducting field work in the Independence

Creek area just northeast of the Onion Valley road. Viewed to the north, the scarp

of the SNFFZ is traced out in this picture.

Figure 13- This picture was taken of an Granitic outcrop during field work in the

Shepherd Creek. This is a representative igneous rock type that composes the

Sierra Nevada igneous mass.

Figure 14- A picture taken of the Topcon differential GPS system that was used in

the field work. The base station sits on the green tripod to the left and the rover is

connected to the yellow tripod. The base station was dedicated and immobile for

the duration of the study.

Figure 15. Plots showing the comparison of Garmin and Topcon derived elevation

data (upper) and the differences between the two data sets (lower) for each station


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on the Independence Creek strand of the SNFFZ. In the upper plot, the red line is a

1:1 line. In the lower plot, the red line shows zero difference between the two data

sets. Note that for Independence Creek the Garmin handheld derived elevations are

5 to 20 m higher than the Topcon elevations.

Figure 16- Plot showing the comparison of Garmin and Topcon derived easting data

for each station on the Independence Creek strand of the SNFFZ. A trend line is

included for the data set. Note the high R2 value indicating consistently similar data

from both devices.

Figure 17- Plot showing the comparison of Garmin and Topcon derived northing

data for each station on the Independence Creek strand of the SNFFZ. A trend line

is included for the data set. Note the high R2 value indicating consistently similar

data from both devices.

Table 1- table listing all the Independence Creek field data collected from both

devices.

Figure 18- Plots showing the comparison of Garmin and Topcon derived elevation


on the Shepherd Creek east strand of the SNFFZ. In the upper plot, the red line is a


sets. Note that for Shepherd Creek east the Garmin handheld derived elevations

range from 0 to 20 m lower than the Topcon elevations.


for each station on the Shepherd Creek east strand of the SNFFZ. A trend line is


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from both devices.


data for each station on the Shepherd Creek east strand of the SNFFZ. A trend line



Table 2- table listing all the Shepherd Creek east field data collected from both

devices.

Figure 21- Plots showing the comparison of Garmin and Topcon derived elevation


on the Shepherd Creek west strand of the SNFFZ. In the upper plot, the red line is a


sets. Note that for Shepherd Creek west the Garmin handheld derived elevations

average out to be almost identical to the Topcon elevations.


for each station on the Shepherd Creek west strand of the SNFFZ. A trend line is


from both devices.


data for each station on the Shepherd Creek west strand of the SNFFZ. A trend line




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Table 3- table listing all the Shepherd Creek west field data collected from both

devices.

Figure 24- Plot of Topcon derived northing and easting data collected from

Independence Creek study area. A strike-parallel line (in red) is added to this plot

for the purpose of calculating the perpendicular distance from the line to a station

point. This plot is generated from an Excel program donated by Professor Fred

Phillips at New Mexico Tech, 2012.

Figure 25- Plot of Topcon derived elevations in the Independence Creek area

compared to the horizontal distance between the station and the strike-parallel line.

This plot has no vertical exaggeration therefore depicting a visual representation of

the fault dip of the SNFFZ in the Independence Creek area. This plot is generated

from an Excel program donated by Professor Fred Phillips of New Mexico Tech,

2012.


Shepherd Creek east study area. A strike-parallel line (in red) is added to this plot



Phillips of New Mexico Tech, 2012.

Figure 27- Plot of Topcon derived elevations in the Shepherd Creek east area



the fault dip of the SNFFZ in the Shepherd Creek east area. This plot is generated


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2012.


Shepherd Creek west study area. A strike-parallel line (in red) is added to this plot



Phillips of New Mexico Tech, 2012.

Figure 29- Plot of Topcon derived elevations in the Shepherd Creek west area



the fault dip of the SNFFZ in the Shepherd Creek west area. This plot is generated


2012.


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Figure 1


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Figure 2


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Figure 3


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Figure 4


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Figure 5

The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again.


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Figure 6



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Figure 7


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Figure 8



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Figures 9 & 10




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Figures 11 & 12




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Figures 13 & 14


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Figure 15


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Figures 16 & 17


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Table 1


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Figures 18


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Figures 19 & 20


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Table 2


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Figure 21


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Figure 22 & 23


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Table 3


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Figures 24 & 25


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Figures 26 & 27


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Figures 28 & 29

Documents

Greg Shagam SNFFZ thesis report complete with …earthsci.fullerton.edu/parmstrong/UNDERGRAD THESES PDF...lack of ridge and ravine topography and relatively less weathering than Qf2a