Sedimentary Rocks Test Flashcards
Clastic
Made from sediments, pieces of other rocks
Sediment size- boulder to sand
Sediment shape- angular, round, sub angular/round
Sediment sorting- very well sorted–> very poorly sorted
3 types of sedimentary rocks
Clastic
Organic
Chemical
Chemical
Made from precipitation of minerals, precipitates- eg. CaCo3 (calcium carbonate), Si02 (silicon dioxide)
Organic
Made from remains of living organisms eg. plants
Sedimentary rock formation
Weathering Erosion Deposition Compaction Cementation
Weathering
Breaking down existing rocks into sediments
Physical- disintegrates into small pieces
Chemical- decomposition of minerals
Erosion
The process which moves sediments
4 forces: water, wind, glaciers, gravity
Water- moves most sizes of sediments
Wind- moves sand sized, small rock through air
Glaciers- moves all sizes
Gravity- moves broken pieces, large/small downslope
Deposition
The process which sediments are layered, settled in body of water
Faster stream is —> bigger sediments can be carried
Deposition by stream- rounded sediments
Deposition by land- angular sediments
Compaction
Sediments are squeezed together by overlying sediments
Cementation
fluids fill space in between loose sediments and crystallize to create
rock
Glue of silicon dioxide or calcium carbonate
Stratification
The layering of strata
Strata is the one that stands out
Cross bedding
Layering of sediments, that is not parallel like stratification
Made from wind or water
You can tell which way the wind was blowing
Ripple marks
Made from the current of running streams/rivers
Tell you direction of current
Mud cracks
When muddy deposits dry up —> shrinking causes mud to crack
Fossils
remains of ancient life
