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CHAPTER 5
The Sedimentary Archives
Multiple Choice Questions
Select the best answer.
1.
A continental platform is part of a (an)
a. Depositional environment.
b. Orogenic belt.
c. Continental shelf.
d. Craton.
e. Shield.
2.
Thick sequence of sedimentary rocks can accumulate when ________.
a. A basin subsides with the accumulation of sediments.
b. A basin uplifts with the accumulation of sediments.
c. A glacier advances.
d. The elevation of the basin does not changed.
e. Both a. and b.
3.
What part of the continent has not been disturbed since the Precambrian?
a. Shield.
b. Orogenic belt.
c. Platform.
d. Craton.
e. All but b.
4.
The continental shelf environment is generally restricted to waters less than
___deep.
a. 2,000 meter.
b. 10,000 feet.
c. 200 meters.
d. 5,000 meters.
e. 25,000 meters.
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5.
Which marine depositional environment tends to host the coarsest sediments?
a. Continental shelf.
b. Continental slope.
c. Deep marine.
d. Streams.
e. Lake.
6.
What continental depositional environment is produced by flowing water?
a. Lacustrine.
b. Eolian.
c. Glacial.
d. Stream.
e. Both a. and b.
7.
What transitional depositional environmental lies immediately inland of a barrier
island?
a. Tidal flats.
b. Lagoons.
c. Barrier island.
d. Continental shelf.
e. Streams.
8.
What element is responsible for red beds?
a. Organics.
b. Silica.
c. Manganese.
d. Iron.
e. Copper.
9.
What is the term that refers to the uniformity of grain sizes?
a. Sorting
b. Roundness
c. Grain size
d. Shape
e. Sphericity
10.
A clastic particle less that 1/256 mm across is called (or named)
a. Boulder.
b. Gravel.
c. Coarse sand.
d. Clay.
e. Sand.
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11.
A sedimentary rock that is poorly sorted with large angular grains was likely
deposited in which one of the following environments?
a. Deep marine.
b. Lagoon.
c. Mountain glacier.
d. Lacustrine.
e. Barrier Island.
12.
A sedimentary structure characteristic of tidal flats is _________.
a. Mud cracks.
b. Cross-bedding.
c. Asymmetric ripple marks.
d. Sole marks.
e. Graded bedding.
13.
What is the name of the sedimentary structure developed on the top of bedding
plain by an oscillatory motion of water?
a. Graded bedding.
b. Cross-bedding.
c. Symmetric ripple marks.
d. Asymmetric ripple marks.
e. Sole marks.
14.
What is the name of the structure where the size of sediment grains fine upwards?
a. graded bedding
b. asymmetric form
c. symmetric form
d. cross-bedding
e. way-up structures
15.
What additional information can be obtained from shape of the cracks in mud
cracks?
a. Thickness of the unit.
b. Lateral extent of the unit.
c. Flow direction of water.
d. The original orientation of the beds.
e. Flow direction of the wind.
16.
In what environment of deposition would arkose sandstone most likely be found?
a. A river delta and river channels.
b. Barrier island and beach.
c. Alluvial fans.
d. Continental slopes (turbidity deposits).
e. Glacial deposits.
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17.
Mature sandstones will contain which of the following characteristics?
a. Well sorted
b. Angular grains
c. Clay
d. Feldspars and pyroxenes
e. Both a. and c.
18.
Modern carbonate sediments forming in the Bahama Banks results primarily from
the presents of ______________.
a. Penicillus.
b. Large invertebrate shells.
c. Öoids.
d. Cold water.
e. Fish skeletons.
19.
Modern environments for carbonate deposition are less common than in the past.
Which of the following helps to explain this difference?
a. Extensive glaciation.
b. Higher global sea level in the past.
c. Extensive shallow seas covering the continents.
d. Generally warmer climates in the past.
e. All but a.
20.
Which of the following is not always true about a formation?
a. Consistent lithology.
b. Distinctive form the units above and below it.
c. Deposited during the same time interval.
d. Can be traced form outcrop to outcrop.
21.
The term facies refers to the part of the rock body that indentifies the _________.
a. Lithofacies.
b. Biofacies.
c. Lithostratigraphic units.
d. Depositional environment.
e. Age of the rock.
22.
An example of a lithofacies is
a. Arkose sandstone.
b. Bioclastic limestone.
c. Micritic limestone.
d. Greywacke sanstone.
e. All the above.
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23.
If sandstone directly underlies shale in a vertical sequence, this is an example of:
a. Biofacies.
b. Offlap sequence.
c. Onlap sequence.
d. Member.
e. Formation.
24.
Walther’s Law states that ___________.
a. Older units are always below younger units.
b. Younger units are always under older units.
c. Onlap and offlap sequences occur.
d. Vertical sequences can be used to predict lateral sequences in the region.
e. Biofacies are equivalent to lithofacies.
25.
Select the vertical sequence that indicates transgression.
a. Sandstone over shale
b. Limestone over conglomerate
c. Conglomerate over sandstone
d. Shale over limestone
e. Conglomerate over limestone
26.
During the maximum glacial advance of the Pleistocene, the Atlantic shoreline
moved _________ seaward.
a. 1 to 2 miles.
b. 100 to 200 kilometers.
c. 1 to 2 kilometers.
d. 500 to 1,000 kilometers.
e. None of the above.
27.
The study of layered rocks is called ___________.
a. Walther’s Law.
b. Lateral continuity.
c. Stratigraphy.
d. Lithofacies and biofacies.
e. Epeiric.
28.
Matching rock bodies by composition, texture, and color is called __________.
a. Chronostratigraphic correlation.
b. Chemotratigraphic correlation.
c. Biostratigraphic correlation.
d. Rhybostratigraphic correlation.
e. Lithostratigraphic correlation.
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29.
Which of the following needs to be consistent between outcrops in order for a
chronostratigraphic correlation to exist?
a. Texture, color, and stratigraphic position.
b. Lithofacies.
c. Plant and animal fossils.
d. Sedimentary structures and textures.
e. Orientation of grains in clastic rocks.
30.
Unconformities are characterized by ______________.
a. Continuous rock record.
b. Gap in the geologic record.
c. Continuous fossil record.
d. Plutonic magma emplacement.
e. Both a. and c.
31.
A nonconformity is defined by _____________________.
a. Younger igneous rocks in contact with older sedimentary rocks.
b. Older tilted sedimentary rocks below younger flat laying sedimentary rocks.
c. Flat lying sedimentary rocks with a significant age difference in the fossils.
d. Younger metamorphic rocks in contact with older sedimentary rocks.
e. Older igneous rocks in contact with younger sedimentary rocks.
32.
The vertical sequence of strata showing structural changes at a given locality is
shown by a ___________.
a. Geologic map.
b. Geologic column.
c. Stratigraphic cross section.
d. Structural cross section.
e. Geologic datum.
33.
What is the name of a map view showing the change in thickness of a geologic
unit?
a. Geologic cross-section
b. Stratigraphic cross-section
c. Structural cross-section
d. Isopack map
e. Paleogeographic map
34.
Geologist measure __________ in the field in order to understand the structure of
a region.
a. Geologic cross-section
b. Strike and dip.
c. Thickness.
d. Age
e. Lithology
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35.
What is the name of the feature that sits between the continental slope and the
deep marine environment?
a. Angular unconformity.
b. Continental rise.
c. Continental shelf.
d. Abyssal plain.
e. Turbidite.
36.
Streams are complex systems that have the type and amount of deposition
controlled by which of the following processes?
a. Discharge.
b. Water velocity.
c. Shape of stream channel
d. Type sediment being transported.
e. All the above
37.
You pick up a sedimentary rock containing pebble size grains. Which of the
following depositional environments is not likely?
a. Stream.
b. Sand dune.
c. Alluvial fan.
d. Delta.
e. Glacial drift.
38.
When sediment removal exceeds sediment accumulation ____________.
a. The delta will build seaward.
b. The delta will be stationary.
c. The delta will not form.
d. A barrier island will form.
e. Both a. and d.
39.
What interpretation can be made from black colored shale?
a. Deposited in an Alluvial fan.
b. Deposited as glacial drift.
c. Deposited in anaerobic quiet water of lake.
d. Iron is common in the shale
e. It is from the Mesozoic Era
40.
Which of the following forms after deposition?
a. Cement.
b. Matrix.
c. Clasts.
d. Cross-bedding.
e. Both a. and b.
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Answers to Questions
1.
2.
3.
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d
a
e
c
a
d
b
d
a
d
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c
a
c
a
d
c
e
a
e
c
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27.
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29.
30.
d
e
c
d
b
b
c
e
c
b
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33.
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35.
36.
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38.
39.
40.
e
d
d
b
b
e
b
c
c
a