Sediments and Sedimentary Rocks

  
       

 

Poorna's "Earth Revealed" (Geol-101) Telecourse: Module 4
Sediments and Sedimentary Rocks
   

 

   Welcome to Poorna Pal's 'Earth Revealed' telecourse (Geology — 101: Physical Geology)
at the Glendale Community College
     
bullet Contact Class Instructor
bullet Contact Instruction Office
bullet Access the Glendale College Library
bullet Search with Google
bullet Search with MSN
 

Visit the URL: http://www.lib.utexas.edu/Libs/GEO/FolkReady/TitlePage.html
to read this online book on this subject

 

bullet

A sediment is a collection of loosened particles of solid rock originating from
 
bullet

weathering and erosion of preexisting rocks

bullet

chemical precipitation

bullet

organic secretion or organic debris

 
bullet

SEDIMENTARY ROCKS form from the consolidation, compaction and lithification/ diagenesis of sediments. This involves
 
bulletweathering and erosion
bullettransportation and deposition
bullet

lithification and diagenesis
 

This USGS site has images and movies of cross-bedding and bedform features in sedimentary rocks: http://walrus.wr.usgs.gov/seds

 

   

bullet

Classification of Sedimentary Rocks:
 
bullet

CLASTIC sedimentary rocks lithify from the sediments, e.g., conglomerates and breccia, sandstones, shales
 

bullet

ORGANIC, BIOGENOUS or BIOCLASTIC sedimentary rocks consolidate from the organic remains, e.g., coal, limestones (such as oolites, coralline limestones), chert etc.
 

bullet

CHEMICAL or HYDROGENOUS sedimentary rocks either
 
bullet

precipitate from solution
(e.g., carbonates like limestones and dolomites) or
 

bullet

form as evaporates
(e.g., gypsum, rock salt).
     
bulletCommon sedimentary structures include bedding, cross-bedding, ripple marks, folds, faults and unconformities.

This University of Oregon site,

http://darkwing.uoregon.edu/~dogsci/dorsey/SedResources.html

has a comprehensive list of web resources on Sedimentary Geology.

 

n    Other resources on the world wide web:

 

This USGS site has images and movies of cross-bedding and bedform features in sedimentary rocks: http://walrus.wr.usgs.gov/seds

This University of Oregon site,

http://darkwing.uoregon.edu/~dogsci/dorsey/SedResources.html

has a comprehensive list of web resources on Sedimentary Geology.

 

 

n    CLASSIFICATION OF SEDIMENTARY ROCKS

–      CLASTIC SEDIMENTARY ROCKS lithify from the sediments, e.g., conglomerates and breccia, sandstones, shales

–      ORGANIC, BIOGENOUS or BIOCLASTIC SEDIMENTARY ROCKS consolidate from the organic remains, e.g., coal, limestones (such as oolites, coralline limestones), chert etc.

–      CHEMICAL or HYDROGENOUS SEDIMENTARY ROCKS either

a.       precipitate from solution (e.g., carbonates like limestones and dolomites) or

b.      form as evaporates (e.g., gypsum, rock salt).

n    The common sedimentary structures include bedding, cross-bedding, ripple marks, folds, faults and unconformities.