Sedimentary Processes and Rocks

 

Terms to learn:

mechanical weathering      erosion                      frost and salt wedging       abrasion
chemical weathering           exfoliation                oxidation                                   hydrolysis
carbonation                              sediments                 lithification                               detrital (clastic)
chemical                                     shale                              sandstone
conglomerate                          breccia                         chert                                            cross-bedding
ripple marks                            graded bedding       mud cracks

 

Topic outline:

1. Weathering
   1. categories
      1. mechanical
      2. chemical
   2. mineral weathering
2. Sediments
   1. Texture
      1. Composition
      2. Size
      3. Effects of transportation
         1. rounding
         2. sorting
   2. Lithification
3. Types of Sedimentary Rocks
4. 1. Detrital (clastic) 
   2. Chemical
   3. Biological
5. Sedimentary structures
   1. Strata (beds) – bedding planes
      1. Cross-bedding
      2. Graded beds - turbidity currents)
      3. Ripple marks – symmetrical and asymmetrical
      4. Mud cracks
6. Depositional environments
   1. Types of environments

 

Interesting places to visit:

Sedimentary structures: http://www.gpc.peachnet.edu/~pgore/geology/historical_lab/sedstructureslab.php

 

Photos of sedimentary structures: http://www.eos.duke.edu/ss/answers1.htm

 

When you are finished with this topic, you should be able to answer these questions:

1.      On what basis are sedimentary rocks classified?

2.      What does sorting and rounding indicate about the transportation of sediment and the energy of the depositional environment?

3.      Which sedimentary structures can indicate direction of water flow?

4.      How is graded bedding formed?

5.      What is the difference between detrital and chemical sedimentary rocks?

6.      What are the steps in lithification?

7.      What depositional environments are indicated by conglomerates? By breccias?