Rick Cheel

Mackenzie Chown D407

Phone: 905-688-5550 ext. 3512

E-mail: rcheel@brocku.ca

Sedimentology

ERSC/GEOG 2P16

All course material, including the course outline, lecture notes and PowerPoint presentations are available from:

http://www.brocku.ca/sedimentology

Grade Distribution

Assignments 25%

Midterm Test 20% Wednesday, Feb. 18, in class

Final Exam 40%

Assignment Test 15% March 29, in lab period

Friday, March 4 is the last date for withdrawal without academic penalty and last day to change from credit to audit status for duration 3 courses.

Textbook: Introduction to Clastic Sedimentology

Downloadable from:http://spartan.ac.brocku.ca/~rcheel/teaching/sedimentology/SedNotes/

Topics to be covered:

1. Grain Texture (fundamental descriptors of granular material)

Grain size

Grain shape

Porosity and permeability

Grain orientation

2. Classification of terrigenous clastic rocks.

Arenite

Rudite

Lutite

3. Unidirectional fluid flow and sediment transport

Characteristics of unidirectional flows

Simple fluid flow

Fluid gravity flows

Sediment transport

Modes of transport

Initiation of transport

4. Bed forms and stratification under unidirectional flows

Bed forms

Terminology

The sequence of bed forms

Bed form stability fields

Cross-stratification formed by bed forms.

Terminology

Origin of cross-stratification

Cross-stratification and bed forms.

5. Flow, bed forms and stratification under oscillatory and combined flows

Characteristics of gravity waves

Bed forms and stratification under symmetrically oscillating currents

Bed forms and stratification under combined flows

The enigma of Hummocky Cross-stratification

Assignment Schedule (Winter, 2011)

January 11 No assignment January 18 No assignment January 25 1. Analysis of Grain Size Data  February 1 Assignment 1 continued February 8 2. Analysis of Grain Shape February 15 3. Analysis of paleocurrent data February 22 Reading Week March 1 4. Classification of clastic rocks March 8 Assignment 4 continued

March 15 5. Paleocurrent problems March 22 Hand in assignment 5 March 29 Assignment Test 

Clastic Sedimentology:

The study of sediment and sedimentary rocks that are made up of particles that are the solid products of weathering at or near the Earth’s surface.

Gravel Sand Mud (silt and clay)

Conglomerate Sandstone Siltstone and Shale

Purpose of the course:

To introduce terminology and fundamental concepts for the description and interpretation of clastic sediment and sedimentary rocks.

Why study clastic sediment?

Sedimentary rocks make up only 7.9% of the Earth’s crust.

66% of the surface of the Earth is covered by sediment or sedimentary rocks.

Humans interact with the Earth largely at or near its surface.

They…..Grow food on it.

Build structures on it. Take resources from it.

At the same time they…..

Modify its physical and chemical properties so that it is no longer useable by them.

It is important to understand the various properties of the sedimentary cover and have systematic methods for describing these properties.

Hide garbage and other waste material in it.

Based on the recognition of the signature of changing environments over time, as preserved in the rock record.

Environmental interpretation of rocks

+

Age of rocks

= Earth History

Sedimentary rocks record the history of changing environments on Earth.

Large scale cross-bedding in 240million year old rocks in the Central US.

= windblown sand dunes; the Central US was a desert at thattime.

By examining the characteristics of various environments on Earth today we can interpret the environments in which ancient sediments were deposited.

The present is the key to the past.

Environmental interpretation:

Age of rocks:

Based on relative age (relative to associated rocks)

or

absolute age (radiometric dating).

Earth History: The history of changing environments on Earth.

ERSC/GEOG 2P16 focuses on:

The description and classification of clastic sediment.

Processes and their products in the sedimentary record that aid in interpreting ancient sedimentary environments.