Please fill out and return this sheet after viewing Program #8.   If you are unsure of an answer, give your best intelligent guess.

1. List some varieties of sedimentary environments.

beaches, lakes, rivers, deltas, ocean bottoms, continental shelves, reefs, barrier islands, glaciers, deserts, etc.

2.  What are size categories of clastic sediments?

gravels    >2mm
sands        1/16 to 2mm
silts            1/256 mm to 1/16 mm
clays          <1/256 mm

3.  What is lithification?  What are two processes of lithification?

process of turning loose sediment into consolidated sedimentary rock; compaction and cementation

4.  Besides lithification of sediment, what are some of the ways that chemical sedimentary rocks form?

accumulation of plant debris (coal); accumulation of marine shell (calcium carbonate) debris (limestone); evaporation of waters rich in dissolved material (evaporites)

5.  What type of rock forms from accumulations of diatoms and radiolaria?

chert (flint)

6.  How does coal form?

Plant debris accumulates and is buried so as to be isolated from the atmosphere which would cause normal decomposition.  Once buried, the plant debris slowly changes into coal.

7.  What are some varieties of sedimentary structures?

ripples, crossbeds, mudcracks, fossils, bedding (among others)

8.  What sedimentary rocks (environments) form crossbeds?

beaches, deserts, rivers

9.  What do mudcracks indicate about a sedimentary environment?

that sediment was deposited by water that subsequently dried up.

10.  What information do sedimentary textures give?

They give information about the environment (see list in question #1) in which the rocks formed, the energy of the environment, and

11.  What are examples of commercial and industrial uses of sedimentary rocks?

gravel, paving material, cement, building material (including bricks and drywall), fuel (coal), and glass (from quartz sandstone)