Sedimentary Rock
description
Transcript of Sedimentary Rock
![Page 1: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/1.jpg)
Sedimentary Rock
http://soest.hawaii.edu/coasts/cgg_main.html
![Page 2: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/2.jpg)
Sedimentary Rocks are the product ofsediment deposition, diagenesis,and lithification
![Page 3: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/3.jpg)
Oceans rise and fall, lakes come and go, streams run and disappear, desertsbecome forests and forest become swamps…all these changes will be recordedin sedimentary rocks
![Page 4: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/4.jpg)
Sedimentary rock contains sediment grains, cement holding them together,and empty space called “pores”
![Page 5: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/5.jpg)
To understand Earth history, a geologist seeks to interpret the “Environment of Deposition” of a sedimentary rock…this reveals something about changes occurring on Earth’s surface
Eolian Environment – grains of uniform size “well sorted”
Coastal Environment – grains coarser and of mixed size
Stream Environment – grains much coarser and “poorly sorted”
![Page 6: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/6.jpg)
Glacial Environment – grains very coarse with no sorting, but usually rounded
Landslide Environment – grains very coarse with no sorting, with no rounding
Marsh/Mudflat Environment – grains very fine
![Page 7: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/7.jpg)
Evaporite environment – chemical sediments
Reef environment – biological sediments
Deep sea environment?? – Plankton sediment and clays from land
![Page 8: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/8.jpg)
Sedimentary Structures….
Sedimentary rocks tend to formlayers or strata…each layer recordsa depositional event
Cross-beds – former dunes
![Page 9: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/9.jpg)
Ripple marks
Mud cracks
modern
ancient
![Page 10: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/10.jpg)
Sediment becomes sedimentary rock…the texture and compositionof the sediment determine the type of sedimentary rock
![Page 11: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/11.jpg)
Two types of sedimentary rock –
Clastic Sedimentary Rock – made of pieces of broken crust
Biochemical Sedimentary Rock – made of precipitated minerals
Conglomerate Rock Salt
![Page 12: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/12.jpg)
Clastic Sedimentary Rock
Conglomerate/Breccia – gravel texture
Sandstone – sand texture
Shale – silt/clay texture
Biochemical Sedimentary Rock
Limestone – CaCO3 composition
Chert – SiO2 composition
Coal – Carbon composition
![Page 13: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/13.jpg)
![Page 14: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/14.jpg)
Pressure forms coalHow does coal form?
![Page 15: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/15.jpg)
Coal strip mine…
![Page 16: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/16.jpg)
Environments of depositionSedimentary texture
Sediment compositionGlobal Climate history
Clastic – Biochemical sedimentary roxBreccia/Conglomerate
SandstoneShale
LimestoneChertCoal
How does coal form?Sedimentary structures
![Page 17: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/17.jpg)
![Page 18: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/18.jpg)
![Page 19: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/19.jpg)
But why was there an ice age?
![Page 20: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/20.jpg)
![Page 21: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/21.jpg)
Ice stores O16 so that oceans are O16 depleted in an ice age
![Page 22: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/22.jpg)
![Page 23: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/23.jpg)
+ O18/O16 -
CaCO3
Layer by layer sampling of plankton reveals oxygenisotope record
Periodicity of 100,000 yrs
![Page 24: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/24.jpg)
100 kyrs
41 kyrs
21 kyrs
![Page 25: Sedimentary Rock](https://reader035.fdocuments.in/reader035/viewer/2022062314/568141f3550346895dadcf48/html5/thumbnails/25.jpg)
These were madeduring an ice age!