Deck 7: Sediment and Sedimentary Rocks

Question 1

The sediment that comprises sedimentary rock may be eroded soil.

Answer 1

True

Question 2

Detrital sediments include any solid particles derived from weathering that are greater than silt-sized.

Answer 2

False

Question 3

Mudflow deposits are very poorly sorted.

Answer 3

True

Question 4

Gravel is sometimes transported by wind.

Question 5

The degree of rounding and sorting is distinctive for different depositional environments.

Question 6

Detrital sedimentary rocks are only formed from sediments produced by mechanical weathering.

Question 7

Only particles of gravel size and larger are transported by glaciers.

Question 8

Streams, waves and currents transport only sediment which is sand size and smaller.

Question 9

Some sedimentary rocks form from material weathered by solution.

Question 10

Chemical sedimentary rocks are only formed from solid particles produced through chemical weathering.

Question 11

Wind transports sediment of sand size only.

Question 12

Fossils consist only of skeletal and shell remains.

Question 13

Fossils may be preserved with their original composition.

Question 14

Fossils are physical oddities of sediment lithification.

Question 15

Fossils are commonly found in igneous and metamorphic rocks.

Question 16

Fossils are preserved only under extraordinary circumstances.

Question 17

The uranium used in nuclear reactors comes only from uraninite in granitic rocks and hydrothermal veins.

Question 18

Stratigraphic traps occur when oil and natural gas are trapped by variations in the sedimentary rock strata.

Question 19

The uranium used in nuclear reactors, carnotite ore, is sometimes concentrated in fossils.

Question 20

Much of the uranium used in nuclear reactors comes from ancient stream channel deposits.

Question 21

The texture and composition of sedimentary rocks does not necessarily reflect

A) the pre-existing rock from which the sediment was derived
B) the weathering processes responsible for creating the sediment
C) the processes by which the sediments were transported
D) the environment in which the sediment was deposited

Question 22

The sediment in sedimentary rocks is derived from

A) solids produced by chemical and mechnical weathering
B) minerals precipitated from solution
C) minerals secreted by organisms
D) A and B
E) all of the above

Question 23

The rounding and sorting of detrital sediment is a function of

A) the transport process or mechanism
B) the transport distance
C) depositional environmental
D) B and C
E) all of the above

Question 24

Sedimentary rocks include

A) any material which has settled from water.
B) organic, rock and mineral fragments, and precipitated minerals.
C) rocks which have been altered by compression.
D) any layered rock consisting of grains.
E) rocks which have been weathered.

Question 25

Which of the following is the correct sequence in which various types of coal are formed?

A) lignite, peat, anthracite, bituminous
B) peat, bituminous, anthracite, lignite
C) peat, lignite, anthracite, bituminous
D) peat, lignite, bituminous, anthracite
E) lignite, peat, bituminous, anthracite

Question 26

During the process of lithification, sedimentary rocks experience which of the following?

A) cementation
B) compaction
C) decreased void space
D) A and B
E) B and C
F)all of the above

Question 27

Relative to a poorly-sorted breccia, the texture of a well-sorted conglomerate may indicate that

A) it was deposited near its source by a debris flow
B) it was deposited by a glacier
C) its sediments were rounded by chemical weathering
D) it was transported and deposited by stream currents or wave action.

Question 28

Hydrocarbons can be widespread in sedimentary rock but reservoirs are formed by

A) porous and permeable beds bounded on all sides by impermeable rock.
B) large cavities such as cave systems in limestone reefs.
C) structural traps.
D) A and C
E) all of the above.

Question 29

The largest known deposits of oil shale occur in

A) the Greenstone formation of Montana.
B) the Green River Formation of Wyoming.
C) the Jurassic salt domes of the Gulf of Mexico.
D) the Athabaskan Formation of Alberta Canada.
E) the La Brea Tar Pits of Los Angeles, California.

Question 30

Oil shale is not a common source of fuel because

A) it cannot be extracted from rock.
B) it is not common enough to be economical.
C) it contains many pollutants.
D) the carbon cannot be economically separated from the rock.
E) it does not burn efficiently.

Question 31

The richest uranium ores in North America are found

A) within and around the Colorado Plateau.
B) in Alberta, Canada.
C) throughout the Rocky Mountain states.
D) in the black shales of the Ohio-Mississippi Valley states.
E) B and

Question 32

Much of the world's iron ore deposits come from rock known as

A) stratified hematite and magnetite.
B) banded hematite.
C) banded iron formation.
D) chemical iron formations.
E) sedimentary iron formation.

Question 33

The 3 most abundant minerals (or mineral groups) in sedimentary rocks are___________,___________, and ___________.

Question 34

A 4th mineral (group) which we can commonly find in these rocks is___________ .

Question 35

The geographic area in which sediments accumulate is termed its ___________ ___________.

Question 36

Three examples of clastic sedimentary rocks are___________ ,___________ ,___________.

Question 37

An example of a carbonate sedimentary rock is___________ .

Question 38

A vertical sequence of a (transgressive/regressive. ___________facies records the landward advance of the sea.

Question 39

Two examples of sedimentary structures are___________ ,___________ .

Question 40

The organic substance found in oil shale which can be processed into liquid oil and combustible gases is___________?

Question 41

Well-rounded sands might be found in different depositional environments. Explain.

Question 42

Explain the basis for sedimentary rock classification using examples and rock names as necessary.

Question 43

Given that sedimentary rocks are either detrital or chemical in origin, relate the classification system generally to the three major environments in which sediments are deposited.

Question 44

How could you distinguish a sedimentary deposit transported by the wind from one transported by a glacier? Why is this so?

Question 45

How does graded bedding form? Describe the type(s) of environments in which you expect it to form.

Question 46

Briefly explain the types of evidence and reasoning that geologists use to infer types of depositional environments. Give one example of how fossils may be used in depositional environment analysis.

Question 47

Why, from production to consumption, is oil shale unlikely as a replacement for petroleum and significant future use as a source of fuel?

Question 48

In which states of the United States is the Green River Formation found?

Question 49

For what two things is the Green River Formation known?

Question 50

List three environmental considerations associated with large-scale mining of the Green River Formation oil shales.

Question 51

What is the basis for classification of detrital sediment and rocks formed from detritus?

Question 52

What materials comprise detrital sediment?

Question 53

What materials comprise chemical sediment?

Question 54

In addition to grain size, what other properties of the particles are used to describe detrital sediment?

Question 55

What is a less common but still important third cementing agent in sedimentary rocks?

Question 56

How could you distinguish calcium carbonate cement from other types?

Question 57

Why is quartz much more common than feldspar in sandstones?

Question 58

What is the source of red, yellow and brown colors in weathered sedimentary rocks?

Question 59

What is the difference between chert, flint and jasper?

Question 60

From what source does the silica in bedded chert come?

Question 61

During what geologic period and age range were the extensive coals in the east and midwest deposited?

Question 62

Which type of coal has nearly been exhausted and which type of coal is common in the western states?

Question 63

How do geologists account for a thickness of 2 km of evaporite rocks beneath detrital sediments under the Mediterranean Sea?

Question 64

What evidence indicates that the Mediterranean Sea once was partially evaporated?

Question 65

What is a secondary sedimentary structure? Give an example.

Question 66

How do geodes form?

Question 67

Distinguish between structural and stratigraphic traps of petroleum and natural gas.

Question 68

Name two economically important uranium-bearing minerals.

Question 69

When did most banded iron formations form?

Question 70

Why was the absence of atmospheric oxygen crucial to banded iron formation deposition?

Question 71

Why are banded iron formations not forming today?