Geology Exam 2
10) Detrital sedimentary rocks form from cemented sediments that are fragments of preexisting rock.
true
11) Sedimentary breccia is a sedimentary rock formed by cementation of angular fragments of gravel.
true
12) Limestone is a sedimentary rock composed mostly of the mineral calcite.
true
13) Sorting is the process by which sediment grains are selected and separated according to grain size.
true
15) Metamorphic rock forms from pre-existing rock when heat and pressure cause solid-state changes.
true
17) Confining pressure is pressure applied equally on all surfaces as a result of burial or submergence.
true
18) Differential stress forces constituents of the rock to become parallel to one another.
true
19) Contact metamorphism occurs when a body of magma intrudes relatively cool country rock.
true
20) If limestone is metamorphosed it recrystallizes into marble.
true
23) Schist forms at higher temperatures and pressure than slate.
true
25) Gneissic texture has the minerals separated into distinct (light and dark) layers.
true
26) The driving force for mass wasting is gravity.
true
27) When soil is saturated with water it becomes heavier and more likely to flow downslope.
true
30) Creep is very slow downslope movement of soil.
true
32) A debris flow is a flowing mixture of soil and water usually moving down a channel.
true
4) An acid is a chemical compound that gives off hydrogen ions (H+) to a chemical reaction.
true
5) Hydrogen ions given off by natural acids can disrupt the crystal structure of most minerals.
true
7) When feldspar is attacked by carbonic acid it forms clay minerals.
true
9) Clay is the finest sediment.
true
The term mechanical weathering refers to changes in a rock that are physical; there is little or no chemical change.
true
to determine the direction the wind was blowing.
Cross-bedding observed in sand dunes can be used:
6) ________ forms as a chemical weathering product of iron-rich minerals. A) Hematite B) Limonite C) Quartz D) Both hematite and limonite are correct. E) All of the choices are correct.
D) Both hematite and limonite are correct.
25) ________ is an organic rock formed from the compression and alteration of plant remains such as leaves, twigs, and tree trunks. A) Crystalline B) Clastic C) Bioclastics D) Coal E) Recycled
D) Coal
31) ________ are polygonal patterns that form in very fine sediment as it dries. A) Ripple marks B) Cross beds C) Burrows D) Mud cracks E) Graded beds
D) Mud cracks
12) The ________ horizon is the dark-colored soil horizon that is rich in organic material and forms just below the surface vegetation. A) A B) B C) C D) O E) E
D) O
9) ________ is the mineral least susceptible to chemical attack on the Earth's surface. A) Olivine B) Calcite C) Halite D) Quartz E) Feldspar
D) Quartz
1) The solution of calcite in a limestone supplies substantial amounts of ________ to ground water. A) calcium ions in solution B) an acid C) bicarbonate ions in solution D) both calcium ions in solution and bicarbonate ions in solution E) All of the choices are correct.
D) both calcium ions in solution and bicarbonate ions in solution
32) In sandstone, a thick bed will often consist of a series of thinner inclined beds called ________. A) laminations B) ripple beds C) graded beds D) cross beds E) tweed beds
D) cross beds
21) In order of decreasing size (largest listed first), sedimentary grain sizes include ________. A) clay, sand, silt, and gravel B) gravel, sand, clay, and silt C) sand, gravel, silt, and clay D) gravel, sand, silt, and clay E) gravel, silt, sand, and clay
D) gravel, sand, silt, and clay
15) Physical disintegration of rock into smaller pieces is called A) chemical weathering B) transportation C) deposition D) mechanical weathering
D) mechanical weathering
13) The rusting of material containing iron is an example of the chemical weathering process of ________. A) exfoliation B) unloading C) hydrolysis D) oxidation E) carbonation
D) oxidation
17) Which is not a type of mechanical weathering? A) frost wedging B) frost heaving C) abrasion D) oxidation
D) oxidation
feldspars are chemically altered to clays.
Hydrolysis occurs when:
build appropriately engineered retaining structures.
One method of stabilizing slopes to prevent mass wasting is:
mechanical weathering
Physical disintegration of rocks into smaller pieces is called:
convergent plate boundaries.
Regional metamorphism is associated with:
is occurring as you read this question. produces foliated metamorphic rocks. produces metamorphic rocks over large areas.
Regional metamorphism:
removal of sharp edges and corners
Rounding of a sediment grain means
low temperature, low pressure conditions.
Shale is a metamorphic rock associated with:
construction on the slope. removing vegetation from the slope. making the slope steeper.
Slopes can be destabilized and the potential for mass wasting increased by:
removal of vegetative cover.
Slopes that have been stable for many years may sometimes fail catastrophically. What is a common trigger for these failures?
carbonic acid
The single most effective agent of chemical weathering at the Earth's surface is:
deeply leached.
Tropical soils are typically:
Rock weathering produces sediment.
Where do sediments come from?
limestone rock salt rock gypsum
Which of the following is a chemical sedimentary rock?
lagoon
Which of the following is considered a low-energy (low-velocity) environment?
slate, phyllite, schist, gneiss
Which of the following lists is arranged in order from lowest to highest grade of metamorphic rock?
Kaolinite
Which of the following minerals is a product of weathering at Earth's surface?
fissile composed of clay minerals forms in low-energy environment
Which of these does not describe shale?
Some form of mass wasting occurs on all slopes.
Which statement is correct?
they are dissolved in water
Which statement is generally true about ions?
a formation.
A body of sedimentary rock of considerable thickness and with features that distinguish it from adjacent rocks is:
26) ________ is a sedimentary rock formed by the cementation of coarse angular fragments of gravel. A) Breccia B) Conglomerate C) Boulder rock D) Arkose E) Cataclastic
A) Breccia
23) ________ is the process by which sediment grains are selected and separated according to grain size by agent of transportation. A) Sorting B) Grading C) Distillating D) Selection E) Segregation
A) Sorting
2) _____ refers to destructive processes that change the physical and chemical character of rocks. A) Weathering B) Extraction C) Erosion D) Deposition E) Provenance
A) Weathering
7) The most important natural source for the formation of acid for rock weathering at the Earth's surface is dissolved ________. A) carbon dioxide B) hydrothermal effluent C) seawater D ) mantle plumes E) comets
A) carbon dioxide
18) The single most effective agent of chemical weathering at Earth's surface is A) carbonic acid H2CO3 B) water H2O C) carbon dioxide CO2 D) hydrochloric acid HCl
A) carbonic acid H2CO3
16) The decomposition of rock from exposure to water and atmospheric gases is called A) chemical weathering B) transportation C) deposition D) mechanical weathering
A) chemical weathering
19) The most common end product of the chemical weathering of feldspar is A) clay minerals B) pyroxene C) amphibole D) calcite
A) clay minerals
talus
An apron of fallen rock fragments that accumulates at the base of a cliff is called:
debris
Any unconsolidated material at the Earth's surface of any size is called:
30) ________ are features found within sedimentary rock that formed during or shortly after deposition. A) Bedding planes B) Sedimentary structure C) Laminations D) Formations E) Turbidity currents
B) Sedimentary structure
4) When feldspar is attacked by carbonic acid it forms ________. A) water, quartz, and potassium B) a clay mineral C) clays and halite D) potassium, calcium, and bicarbonate ions E) potassium feldspar, which does not undergo chemical weathering
B) a clay mineral
14) Which of the following minerals is completely dissolved by carbonic acid? A) Hematite B) Feldspar C) Calcite D) Quartz E) Biotite
C) Calcite
27) ________ are sedimentary rocks deposited by direct precipitation of minerals from water. A) Hydro rocks B) Clastic rocks C) Chemical rocks D) Aquatic rocks E) Biologic rocks
C) Chemical rocks
29) ________ is a hard, compact, very fine-grained sedimentary rock composed entirely of silica. A) Tuff B) Chalk C) Chert D) Travertine E) Claystone
C) Chert
34) In which of the following environments of deposition would shale most likely be created? A) River bed B) Beach C) Deep lake bottom D) Alluvial fan E) Under a glacier
C) Deep lake bottom
1)________ is the picking up and physical removal of rock particles. A) Weathering B) Extraction C) Erosion D) Deposition E) Provenance
C) Erosion
10) Compared with quartz, minerals that include the positively charged ions of aluminum, iron, magnesium, and calcium are ________ vulnerable to chemical weathering by acidic solutions. A) just as B) less C) more D) not
C) more
3) Ferromagnesian (iron-bearing) minerals are chemically altered in the presence of ________. A) quartz B) helium C) oxygen D) argon E) mica
C) oxygen
5) Water that has trickled down into a joint in a rock can freeze, expand, and ________. A) glue the rock more tightly together B) make the rock harder C) seal the crack thereby preventing further weathering D) widen the crack and hastening the rock's disintegration E) displace surface acids that may weaken the rock
D) widen the crack and hastening the rock's disintegration
yes, roundness increases
Does grain roundness generally change with increasing distance from source area?
24) ________ is a term that describes a series of visible layers in sedimentary rock. A) Units B) Tables C) Sheets D) Planes E) Bedding
E) Bedding
22) ________ is a coarse-grained sedimentary rock formed by the cementation of rounded gravel. A) Breccia B) Mega sandstone C) Pebble rock D) Boulder rock E) Conglomerate
E) Conglomerate
8) ________ are commonly left after complete chemical weathering. A) Olivine and calcium plagioclase B) Orthoclase feldspars C) Halite and gypsum D) Calcite and dolomite E) Quartz and clay minerals
E) Quartz and clay minerals
20) The most common end product of the chemical weathering of quartz is A) clay minerals B) pyroxene C) amphibole D) calcite E) Quartz does not weather chemically.
E) Quartz does not weather chemically.
28) A(n) ________ is sandstone containing a significant amount of feldspar. A) marble B) quartz sandstone C) greywacke D) shale E) arkose
E) arkose
33) Rock salt and gypsum are both ________. A) carbonates B) sandstones C) types of coal D) fine-grained clastics E) evaporites
E) evaporites
alignment of mineral grains in metamorphic rocks
Foliation is:
calcite
Limestone is composed of the mineral
non-foliated
Metamorphic rocks in which minerals are NOT aligned within the rock are:
clay
The common solid end product of the chemical weathering of feldspar is:
chemical weathering
The decomposition of rock from exposure to water and atmospheric gases is known as:
gravity
The driving force behind all mass wasting processes is:
slightly acidic
The normal pH of rainwater is:
heat and pressure
The principal agents of metamorphism are:
shear strength.
The resistance to movement or deformation of debris is its:
14) The principle of superposition states that in a stack of horizontal layers the oldest layer is on top.
false
16) Metamorphism includes melting.
false
21) Metamorphic rocks owe their texture mostly to temperature.
false
22) A metamorphic rock is similar both in mineralogy and texture to its parent rock.
false
24) Schist is a metamorphic rock characterized by a nonfoliated texture.
false
28) Surface tension created by a small amount of water in soil decreases its shear strength.
false
29) A debris flow is a very rapidly moving turbulent mass of broken up bedrock.
false
3) All rocks chemically weather the same way.
false
31) The type of material involved doesn't matter in how a mass wasting event is classified.
false
6) Landslides that take place underwater are called waterslides.
false
8) The single most important agent for the chemical weathering is temperature.
false
Chemical weathering will eventually change a quartz crystal into clay minerals.
false