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Flashcards in Geo Unit 3 Deck (23):
1

What is Bedding/Stratification?

When sediment is deposited as distinct layers (beds)

2

What are the two types of Stratification?

Graded Bedding and Cross-Bedding

3

What is Graded Bedding?

Coarse grains settle out on the bottom of beds, and finer sediments at the top

4

Why are the finer grains at the top of graded bedding?

Decrease in energy

5

What causes Graded Bedding?

Turbidity currents from underwater slope failure

6

What is Cross-Bedding?

layers at an angle within a given bed

7

What causes cross-bedding?

wind or water causes sediment to move as distinct bedforms

8

What are the different forms of cross-bedding?

Ripples from low velocity and dunes from higher velocity

9

Can you determine the direction of movement and what is "up" in cross-bedding?

Yes

10

What are the two types of ripples?

Symmetric and Asymmetric

11

What causes mudcracks?

Fine-grain homogenous material shrinks upon drying

12

What is the form of mudcracks?

V-Shaped, downward cracks

13

What is the PHYSICAL Process involved in Lithification?

Compaction

14

What happens during Compaction?

volume decrease and closer packing of particles

15

What is Porosity?

the open space between particles

16

What is Permeability?

the ability of fluids to flow in sediment

17

What is the CHEMICAL Process involved in Lithification?

Cementation

18

What happens during Cementation?

The grains are bound together and the porosity is reduced/filled

19

What are the common types of cement for Cementation?

Silica (Quartz), Calcite, and Iron

20

Compaction and Cementation affect ___ sedimentary rocks.

ALL

21

What are the four classifications of sedimentary rocks?

Clastic, Chemical, Biochemical, and Miscellaneous

22

How are clastic sedimentary rocks classified?

by particle size

23

What is the mineralogy of clastic sedimentary rocks?

Quartz for sand, clay for finer sizes, and feldspars in immature sediments