Sedimentary Geology Geos 240

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Sedimentary GeologyGeos 240 Chapter
3-3Sedimentary Petrology-3

• Dr. Tark Hamilton
• Camosun College

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L?RMudSilty MudSandy MudMuddy
Silt/SandBreccia/ Conglomerate
Field
Lab
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Limestone names Dunham/Folk
Lime mudstone/Micrite
Wackestone/Biomicrite
Intrasparite Grainstone/Sparry Biomicrudite
Packstone/Oomicrite
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Facies Map of Andros IslandE.G. Purdy 1963,
Jour. Geol. Satellite View
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B
A
C
D
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S
B
Stromatoporoid Bryozoan Biosparite Grainstone
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Dolomite Rhombs Replacing Cretaceous Chalk
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Dolostone Collapse Breccia, NWT
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Folded Radiolarian Chert, J. Cache Creek Fm.
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Diagenesis in Clastic Sediments
Q
Bt
F
Hb
F
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Niagara Escarpment Resistant cap of Silurian
Lockport Dolostone overlies Ordovician Limestone
Shale
The escarpment is a Cuesta which forms the North
edge of the Michigan Basin.
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Click on photo for higher resolution.
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
     
Stromatoporoids, Lockport Dolomite, NY
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Ordovician packstone (biomicrite)photo by
Madeline Ernst

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Stylolites
Ord. Limestone
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Diagenesisin LimestonesMicrite
recrystallizesto Sparite
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Petrographic Goals for the Course

• Distinguish siliciclastic (detrital) from
  carbonates
• Be able to correctly name a rock from its grain
  and matrix composition and texture e.g.
  feldspathic sandstone, lithic wacke, carbonaceous
  shale
• Distinguish quartz, feldspar, micas, Fe-oxides
• Describe grain size, shape and grain size
  distributions using a microscope
• Distinguish grains, matrix, cement porosity
• Recognize grain alignment, sedimentary layering

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Petrographic Goals for the Course

• Distinguish Carbonate from detrital rocks
• Be able to recognize and name various types of
  allochems (grains) and distinguish them from
  matrix, cements porosity
• Distinguish cement types carbonate, quartz,
  hematite
• Distinguish fossils, ooliths and pellets
• Distinguish calcite and aragonite from dolomite
• Classify carbonates by Dunham and Folk schemes
• Distinguish various types and s of porosity