Chapter 7: Sediment and Sedimentary Rocks Flashcards
Sediment
eroded and deposited material
Detrital Sediment
solid load (mechanical weathering) -The further sediments are transported, the smaller, more rounded, and more well sorted the rock will be
Bed load
sediments transported along the water surface
Suspended load
sediments transported floating on the water surface
Detrital Sedimentary Rocks
Conglomerate, Breccia, Sandstone, Siltstone, Shale
Chemical Sediments
Dissolved load
Chemical Sedimentary Rocks
Chemically precipitated
- Evaporites: Rock salt, rock gypsum
- Carbonate: Limestone, Dolostone
Biochemical Sedimentary Rocks
Biologically precipitated
- Most limestone, chert
- Crystalline or bioclastic texture
Sedimentary Environment
Where sediment is deposited, usually cause of reduced energy
-Continental (terrestrial),Transitional, Marine
Sedimentary Facies
all characteristics of a rock that reflects its depositional environment
Energy
Winnowing(sorting), Formation of sedimentary structures like stratification, ripples, cross-bedding, and graded bedding (turbidity current)
Activity of Organisms
Fossils and biogenic sedimentary structures like trails and burrows
Lithification
Compaction(burial depth) and cemetation(length of burial allows for groundwater containing dissolved chemicals to deposit in pore spaces
- Calcite and Silica: clear, submarine
- Iron oxide (hematite): red, subaerial
Cross-bedding
Layers arranged at an angle to the surface on which they are deposited
Graded-bedding
An upward decrease in grain size, deposited by turbidity currents, underwater flows of sediments that have a greater density than sediment-free water
