Download Please read chapters 10 and 5 CHAPTER 5–Sedimentary Rocks 1

Please read chapters 10 and 5
CHAPTER 5–Sedimentary Rocks
1) Sedimentary rocks
A) form by compaction and cementation of loose sediment.
B) are widespread on the continents and ocean floor.
C) are common on the stable platforms of all continents.
D) may be found in folded layers in mountain belts.
E) all of the above
Answer: E
2) The mineral calcite (CaCO3) is the major constituent of
A) limestone.
B) dolomite.
C) shale.
D) coal.
E) sandstone.
Answer: A
3) The major constituent of most sandstone is
A) quartz.
B) feldspar.
C) olivine.
D) garnet.
E) calcite.
Answer: A
4) Which of the following is the most abundant nonclastic rock (deposited by chemical or organic means)?
A) marine limestone
B) rock salt
C) dolostone
D) gypsum
E) dripstone
Answer: A
5) Which of the following is the most common clastic rock?
A) pebble-sized conglomerate
B) gypsum
C) shale
D) cobble-sized conglomerate
E) sandstone
Answer: C
6) Which of the following rock types is NOT considered to be clastic?
A) rock salt
B) conglomerate
C) siltstone
D) sandstone
E) shale
Answer: A
7) A clastic sedimentary rock composed of rounded to subrounded gravel is called a
A) coal.
B) shale.
C) breccia.
D) conglomerate.
E) sandstone.
Answer: D
8) Transportation and deposition of sediment by turbidity currents is commonly indicated by
A) mud cracks.
B) cross-bedding.
C) graded bedding.
D) ripple marks.
E) horizontal laminae.
Answer: C
9) Which of the following are good indicators of ancient current direction?
A) mud cracks
B) graded bedding
C) degree of sorting
D) cross-bedding
E) all of the above
Answer: D
10) A sequence of rocks produced by a single regression (retreat) of the sea would be (from lowest to highest)
A) shale-limestone-sandstone.
B) sandstone-limestone-shale.
C) limestone-shale-sandstone.
D) shale-sandstone-limestone.
E) sandstone-shale-limestone.
Answer: C
11) Cross-bedding is commonly found in
A) coal.
B) shale.
C) sandstone.
D) rock gypsum.
E) rock salt.
Answer: C
12) In graded bedding, the size (diameter) of the sediment particles in a single layer
A) is uniform from top to bottom.
B) ranges from coarsest at the top to finest at the bottom.
C) ranges from coarsest at the bottom to finest at the top.
D) ranges from fine to coarse to fine in a vertical sequence.
E) none of the above
Answer: C
13) The proper interpretation of a vertical sequence of rock consisting of sandstone at the base, overlain by shale
and then limestone, would be
A) a regression of the sea.
B) a change from glacial to fluvial environments.
C) a transgression of the sea.
D) an alluvial fan overlain by fluvial sediments.
E) a cycle of transgression and regression of the sea.
Answer: C
14) Alternating layers of coal, shale, and sandstone would have been deposited in which of the following
environments?
A) lagoon
B) alluvial fan
C) tidal flat
D) beach
E) shallow marine
Answer: A
15) Fossil remains of ancient organisms are most commonly found in
A) basalt.
B) granite.
C) metamorphic rocks.
D) gypsum.
E) sedimentary rocks.
Answer: E
16) Most clastic sedimentary rocks are consolidated by the process of
A) recrystallization.
B) heating and annealing of grains.
C) cementation.
D) metamorphism.
E) deposition.
Answer: C
17) The separation of detrital grains according to size is called
A) sorting.
B) graduating.
C) desiccation.
D) collimating.
E) none of the above
Answer: A
18) Which of the following rock types forms from solid pieces of other, older rocks?
A) sandstone
B) granite
C) chert
D) rock gypsum
E) rock salt
Answer: A
19) A limestone with numerous fossil corals, fossil sponges, and other fossils, little or no stratification, an absence
of cross-bedding and ripple marks. In which environment was this limestone formed?
A) an organic reef
B) the deep ocean
C) a beach
D) a delta
E) a tidal flat
Answer: A
CHAPTER 10–Weathering
1) After a granite has weathered and most of the igneous minerals have been altered to other minerals which
igneous mineral will probably NOT have been affected?
A) potassium feldspar
B) mica
C) amphibole
D) quartz
E) plagioclase feldspar
Answer: D
2) The iron minerals hematite and limonite result from the chemical weathering of iron-rich minerals by the process
of
A) oxidation.
B) dissolution.
C) electrolysis.
D) exsolution.
E) exfoliation.
Answer: A
3) Which of the following common rocks would be most susceptible to chemical weathering?
A) sandstone
B) slate
C) granite
D) shale
E) limestone
Answer: E
4) Chemical weathering would progress most rapidly in
A) the Rocky Mountains of Colorado, western USA.
B) northern South America, i.e. the Amazon River Basin
C) New Mexico, southern USA.
D) the Great Lakes, northern USA.
E) Greenland.
Answer: B
6) Ice wedging is important in preparing rocks for chemical weathering because it
A) resists in downslope movements.
B) produces swelling as certain minerals are altered to clay.
C) enlarges fractures and cracks, thereby increasing the surface area of the rock.
D) reduces the rock to its constituent minerals.
E) all of the above
Answer: C
7) Ice wedging would be most effective in
A) the permafrost areas of the north.
B) areas where freezing and thawing occur many times a year.
C) areas where it is cold enough to produce long periods below 0 degrees celsius.
D) areas beneath the glaciers in Antarctica and Greenland.
E) latitudes where strong heating occurs.
Answer: B
8) Which of the following changes takes place during the chemical weathering of granite?
A) feldspar increases and clay decreases
B) clay increases and feldspar decreases
C) clay decreases and iron oxide increases
D) quartz and plagioclase decrease and K-feldspar increases
E) clay increases and feldspar increases
Answer: B
9) Which of the following minerals is most resistant to chemical weathering?
A) plagioclase
B) quartz
C) olivine
D) calcite
E) hornblende
Answer: B
10) Which of the following common rock-forming minerals weathers to form most of the clay found in soils and
regolith?
A) calcite
B) feldspar
C) quartz
D) halite
E) mica
Answer: B
11) Joints aid in chemical weathering by
A) expanding the rock.
B) providing passageways for water and gases.
C) increasing the surface area exposed to weathering agents.
D) all of the above
E) only B and C
Answer: C
13) The general term for the blanket of loose rock debris that covers large areas of Earth's surface is
A) bedrock.
B) regolith.
C) outcrop.
D) lithic layer.
E) laterite.
Answer: B
15) A talus accumulation consists largely of
A) coarse, angular rock fragments.
B) soil.
C) a mixture of silt and ice.
D) alternate layers of clay and sand.
E) clay rich in colloids.
Answer: A
16) Physical weathering would progress most rapidly in
A) the Rocky Mountains of Colorado.
B) northern South America, i.e. the Amazon River Basin
C) North Africa.
D) the Caribbean Islands.
E) Greenland.
Answer: A
17) Which of the following is NOT a type of physical weathering?
A) conversion of feldspar minerals to clay and soluble material
B) unloading
C) frost action
D) splitting by tree roots
E) none of the above
Answer: A
18) When granite weathers its quartz grains
A) dissolve completely.
B) remain essentially unaltered.
C) alter into clays.
D) are replaced with silica.
E) react with water to form soil.
Answer: B
19) During ________ weathering, the original minerals can be destroyed, and new minerals formed that are stable
at Earth's surface.
A) chemical
B) physical
Answer: B
20) Which of the following minerals is most stable at Earth's surface?
A) plagioclase feldspar
B) augite, a pyroxene
C) hematite (a chemical formula Fe2O3)
D) olivine (chemical formula Mg2SiO4)
Answer: C
22) The products of ice wedging often accumulate at the bases of cliffs to form piles of angular rock fragments
called
A) talus.
B) a soil profile.
C) bedrock.
D) exfoliation domes.
Answer: A
26) Which rock type, limestone, granite, or basalt, would weather to form the most clay? Which would be most
susceptible to oxidation?
Answer: Granite would weather to form the most clay because it has the highest abundance of the parent mineral
(feldspar) for the clay. would be the most susceptible to change by oxidation, because it has the highest
concentration of iron--the main component that is affected by oxidation in rocks.
27) Which rock types are most susceptible to chemical weathering?
Answer: Carbonates, gypsum, and rock salt are most susceptible to chemical weathering. Among the silicates, rocks
with olivine and feldspar weather more readily than others.