Sedimentary Rocks Flashcards
0
Q
Chemical
A
-made from precipitates such as CaCo3 and SiO2
1
Q
Clastic
A
- made of sediments
- sediment size, shape, and sorting
2
Q
Organic
A
-made from remains of living organisms
3
Q
Weathering
A
- Physical: breaks rocks apart
- Chemical: dissolves less stable minerals
- breaking down existing rocks to sediments
4
Q
Erosion
A
- transportation by water, wind, ice, gravity (below)
- rivers - river load - suspended load, dissolved load, bed load
5
Q
Deposition
A
- settling of sediments into layers, typically in large body of water
- rates based on sediment size, shape, density
6
Q
Compaction
A
-flattening of layers due to pressure from layers or sediments above
7
Q
Cementation
A
- the “gluing together” of sediments using CaCO3 (calcite) or SiO2 (qtz) as they precipitate and become solid from water
8
Q
Stratification
A
- layers, bed, strata, unit
- stratigraphic columns
9
Q
Crossbedding
A
- made from wind or water
- layers cross
- sediments are being deposited by fluids (air, wind, water).
10
Q
Ripple marks
A
- made from the current of running streams/rivers
- show direction of current in river
11
Q
Mud cracks
A
- water dries up and shrinks sediment layer (contraction)
- arid environment- evaporated water
- form in dry places
12
Q
Fossils
A
remains of ancient life
13
Q
What is a sedimentary rock?
A
- formed on surface of earth
- rocks & pieces of once living materials that are cemented together
14
Q
sedimentary rocks are formed from…
A
- pre-existing rocks
- organisms
- sediments [eg. sand, pebbles, boulders, shells, living material (organic)]
