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Flashcards in Ch7 Deck (36):
0

Flint, chert, and jasper are microcrystalline forms of

Quartz

1

What us probably the single most important, original, depositional feature in sedimentary rocks

Bedding or stratification

2

A graywacke is

A sandstone with sand grains embedded in a clay rich matrix

3

Which of the following applies to the basic constituents of halite, gypsum, and sylvite

Transported as dissolved ions; deposited by evaporation

4

Compaction is a very important part of lithification process for which of the folllowing sediments?

Mud

5

Which characteristic is absolutely necessary for a sedimentary rock to have potential as a possible reservoir rock for oil or gas

High porosity

6

A cherty limestone would contain which major constituents

Silica; calcite

7

____ cement produces bright red and yellow colors on some sandstone

Iron oxide

8

Studies of deep sea sediment views have contributed greatly to scientific knowledge of

Climatic changes during the last four million years

9

Which of the following sedimentary features would typically be found in shales but not in sandstones?

Mud cracks

10

Detrital sedimentary rocks are classified based on the

Grain sizes of the detrital particles

11

Which of the following is not a type of limestone

Arkose

12

____ a common mineral found in igneous rocks, is the most abundant mineral in detrital sedimentary rocks

Quartz

13

Which of the folllowing sedimentary features can each be used to determine paleocurrent directions

Ripple marks and cross stratification

14

Oolitic limestone is most likely to form in what type of depositional environment

Shallow, clear, marine waters with vigorous current activity

15

Which of the following describes the correct order for relative solubility of minerals in sedimentary rocks

Evaporate minerals are more soluble than calcite and quartz

16

Which type if limestone consists mainly of tiny, marine fossils composed of calcite

Chalk

17

___ sandstone contains abundant feldspar, suggesting that the sand was derived by weathering and erosion if granitic bedrock

Arkosic

18

Which of the following best describes bedding gypsum and halite

Evaporates, chemical, sedimentary rocks

19

Sedimentary rocks account for about what percentage of the earths outermost 10km

5%

20

What percentage of the earths continental area is covered by sedimentary rocks

75

21

Coal beds originate in

Freshwater coastal swamps and bogs

22

___ is a form a calcium carbonate

Travertine

23

Which of the following sedimentary rocks would you expect to have orginally been deposited by fast moving streams

Conglomerate

24

What is the main difference between conglomerate and breccia

Breccia clasts are angular, conglomerate clasts are rounded

25

___ is not a common cementing aging for sandstone

Fluorite

26

Boulder conglomerates suggest deposition by strong winds in a desert

False

27

Chalk, coquina, and ancient coral reefs are primarily composed of microcrystalline quartz

False

28

Clay and muddy sediments lithify to form shales and mudstones

True

29

Detrital sedimentary rocks are classified according to clastic particle size; chemical sedimentary rocks are named according to the most abundant minerals

True

30

Graywacke sandstones are typically better sorted than sandstones lithified from ancient beach sand

False

31

Many limestones are biochemical in origin

True

32

Mud cracks in a shake or mudstone indicate that the mud or clay was deposited in feels waters if an offshore marine environment

False

33

Peat is thought to be the original material from which coal is formed

True

34

The mineral dolomite, which is the major mineral of the sedimentary rock dolostone, is a carbonate of rich calcium and magnesium

True

35

Water is gradually expelled from compacting clay and mud sediments

True