GEO 102 Exam 2

47) Which one of the following regarding the San Andreas Fault in California is true? A) a sliver of continent west of the fault is moving northward with the Pacific plate B) continental crust east of the fault is moving east with the North American plate C) the North American plate is slowly moving northward with respect to the continental fragment west of the fault D) a sliver of land west of the fault is sinking under the North American plate

A) a sliver of continent west of the fault is moving northward with the Pacific plate

10) Studies of deep-sea sediment cores have contributed greatly to scientific knowledge of ________. A) climatic changes during the last four million years B) how soft-bodied organisms are carbonized 10) _____ C) the biological impacts of pollution on parts of the continental shelves D) the origin of oscillation ripple marks in deep-sea muds

A) climatic changes during the last four million years

43) The ________ magnitude scale is a measure of the energy released. It does not directly measure the extent of building damage. 43) _____ A) Richter B) Mercalli C) Gutenberg D) Reid

Richter

49) Which one of the following best characterizes the asthenosphere? A) a zone of hardened, silicate rock at the base of the oceanic crust B) a zone of softened peridotite in the upper mantle C) the zone in the mantle from which hot-spot magmas are melted D) a layer of soft, solid, magnesium silicates and molten iron droplets at the base of the mantle

a zone of softened peridotite in the upper mantle

6) Which major component of detrital sedimentary rocks only rarely occurs as a primary mineral in igneous rocks? 6) _____ A) ferromagnesian minerals B) quartz C) carbonates D) clays

clays

38) Normal and reverse faults are characterized mainly by ________. A) dip slip B) strike slip C) horizontal slip D) basal slip

dip slip

30) ________ is an erosional contact between tilted, older strata below and horizontal, younger strata above. 30) _____ A) Inverse bedding B) An angular unconformity C) Cross cuttingD) A disconformity

An angular unconformity

4) ________ sandstone contains abundant feldspar, suggesting that the sand was derived by weathering and erosion of granitic bedrock. 4) _____ A) Arkosic B) Oolitic C) Quartz-rich D) Lignitic

Arkosic

12) ________ are further concentrated in a residual brine after NaCl is crystallized. A) Magnesium, calcium, and sulfur B) Potassium, magnesium, and bromine C) Iron, sodium, and chlorine D) Calcium, sulfur, and titanium

B) Potassium, magnesium, and bromine

9) Which characteristic is absolutely necessary for a sedimentary rock to have potential as a possible reservoir rock for oil or gas? 9) _____ A) chemical origin B) high porosity C) clastic texture D) good stratification

B) high porosity

3) What is a bittern? 3) _____ A) an evaporate sedimentary rock rich in gypsum and halite B) residual brine left after precipitation of halite C) an algal limestone mound deposited in an atoll lagoon D) the dark-gray, clay-rich matrix of an arkose

B) residual brine left after precipitation of halite

2) What is the main difference between a conglomerate and a sedimentary breccia? A) Breccia clasts are the size of baseballs; conglomerate clasts are larger. B) Breccia has a compacted, clay-rich matrix; conglomerate has no matrix. C) Breccia clasts are angular; conglomerate clasts are rounded. D) A breccia is well stratified; a conglomerate is poorly stratified.

C) Breccia clasts are angular; conglomerate clasts are rounded.

7) What is the chemical formula for dolomite, the major mineral in dolostones? A) SiO2 B) CaSO4 2H20 C) CaMg(CO3)2D) NaCl

C) CaMg(CO3)2

5) Which of the following describes the correct order for relative solubility of minerals in sedimentary rocks? A) Evaporate minerals, quartz, and calcite all have the same relative solubility. B) Evaporate minerals are less soluble than quartz and calcite. C) Evaporate minerals are more soluble than quartz and less soluble than calcite. D) Evaporate minerals are more soluble than calcite and quartz.

D) Evaporate minerals are more soluble than calcite and quartz.

20) In which setting would regional metamorphism be most likely? 20) _____ A) at shallow depths beneath the seafloor where water pressures are immense B) at shallow depths below an oceanic ridge or rift zone C) at shallow depths along major transform faults in the continental crust D) at great depths in the crust where two continents are colliding

D) at great depths in the crust where two continents are colliding

13) Amphibolite is a foliated metamorphic rock composed principally of hornblende and plagioclase. How does it form? 13) _____ A) by the impact of an asteroid on interbedded sandstone and shale B) by contact metamorphism of sandstone along the contact with a granitic batholith C) by gouging and crushing of limestone along a fault D) by regional metamorphism of volcanic rocks such as andesite and basalt

D) by regional metamorphism of volcanic rocks such as andesite and basalt

11) Which type of limestone consists mainly of tiny, marine fossils composed of calcite? A) chertB) dolostone C) coquina D) chalk

D) chalk

1) Coal beds originate in ________. A) shallow lakes in a dry, desert region C) channels of fast-moving streams 1) _____ B) deep, marine basins below wave action D) freshwater coastal swamps and bogs

D) freshwater coastal swamps and bogs

21) ________ is a nonfoliated rock formed by contact metamorphism of a shale or mudstone. A) Marble B) Gneiss C) Hornfels D) Schist

Hornfels

8) ________ is the most common type of chemical sedimentary rock. 8) _____ A) Phosphate rock B) Limestone C) Chert D) Quartz sandstone

Limestone

50) ________ are much more abundant in mantle rocks than in crustal rocks. 50) _____ A) Quartz and calcite B) Hydrous minerals like micas and clays C) Magnesium silicates D) Potassium aluminum silicates

Magnesium silicates

14) ________ forms from the metamorphism of limestone or dolostone. 14) _____ A) Marble B) Amphibolite C) Quartzite D) Migmatite

Marble

15) What two, metamorphic rocks are composed predominantly of single minerals? A) mica schist and granitic gneiss B) marble and quartzite C) garnet schist and hornfels D) fault breccia and graphitic schist

Marble and quartzite

52) The ________ is the seismic discontinuity that forms the boundary between the crust and mantle. A) Moho B) Mojo C) Mogo D) Moto

Moho

45) ________ was struck by three major earthquakes during the winter and spring months of the years 1811-1812. 45) _____ A) Charleston, South Carolina B) Los Angeles, California C) New Madrid, Missouri D) Nome, Alaska

New Madrid, Missouri

23) ________ is typically formed by metamorphism of a sandstone. A) Slate B) Quartzite C) Marble D) Amphibolite

Quartzite

39) Which one of the following statements regarding rock deformation and strength is correct? A) Elastic deformation is accomplished through internal flow of material. B) Rupture and plastic deformation occur when stresses exceed the elastic limit of a material. C) Rocks undergo plastic deformation less readily as temperatures and pressures increase. 39) _____ D) When rocks are subjected to stress for long time periods, very small, plastic deformations accumulate to produce large, permanent, elastic deformations.

Rupture and plastic deformation occur when stresses exceed the elastic limit of a material.

42) The ________ earthquake was accompanied by extensive fire damage.42) _____ A) Anchorage, 1964 B) Mexico City, 1985 C) San Francisco, 1906 D) Yerevan, Armenia, 1988

San Francisco, 1906

25) Which of the following geologic observations would not bear directly on working out the sequence of geologic events in an area? 25) _____ A) the feldspar and quartz contents of a granite B) an unconformity between a granite and sandstone C) inclusions of sandstone in a granite pluton D) a well-exposed dike of basalt in sandstone

The feldspar and quartz contents of a granite

16) Graphite is identified in a particular schist. Which one of the following conclusions is justified? A) The graphite lubricated shearing movements along a fault, causing a schist to form. B) The pre-metamorphic rock was a shale or mudstone containing organic matter. C) The rock also contains diamonds; both are crystalline forms of the element carbon. D) The schist formed from a quartz-rich, sedimentary limestone.

The pre-metamorphic rock was a shale or mudstone containing organic matter.

35) ________ in layered sedimentary rocks are evidence for horizontal compression and shortening. A) Tight folds B) Horsts and grabens C) Strike-slip faults D) Normal faults

Tight folds

24) Which of the following best characterizes an angular unconformity? A) Tilted strata lie below the unconformity with loose, unconsolidated soil above. B) The discordant boundary between older strata and an intrusive body of granite. C) Horizontal lava flows lie below the unconformity and horizontal, sedimentary strata lie above. D) Tilted strata lie below the unconformity; bedding in younger strata above is parallel to the unconformity.

Tilted strata lie below the unconformity; bedding in younger strata above is parallel to the unconformity.

37) A syncline is ________. 37) _____ A) a fold in which the strata dip away from the axis B) a fold with only one limb C) a fold characterized by recumbent limbs D) a fold in which the strata dip toward the axis

a fold in which the strata dip toward the axis

41) P waves ________. 41) _____ A) are faster than S waves and surface waves B) propagate only in solids C) produce the strongest ground shaking D) have higher amplitudes than do S waves

are faster than S waves and surface waves

40) The Michigan geologic map shows older, Paleozoic strata (in roughly circular patterns) surrounding a core area of Pennsylvanian rocks. What is this structure? 40) _____ A) dome B) basin C) anticline D) recumbent horst

basin

26) The half-life of carbon-14 is about 6000 years. Assume that a sample of charcoal is formed by burning of living wood 15,000 years ago. How much of the original carbon-14 would remain today? 26) _____ A) between one-fourth and one-eighth B) between one-half and one-fourth C) between one-half and one-third D) more than one-half

between one-fourth and one-eigth

51) Which of the following best characterizes how the diameter of Earth's core and the nature of the outer core were discovered? 51) _____ A) Crystalline iron was found in lavas erupted from the deepest known hot spots. B) because P-wave speeds are higher in the outer core than in the lower mantle. C) by using the ratio of iron meteorites to stony meteorites to deduce the relative diameters of the core and mantle D) by analysis of the P-wave and S-wave shadow zones

by analysis of the P-wave and S-wave shadow zones

18) What major change occurs during metamorphism of limestone to marble? A) calcite grains are dissolved away leaving only marble crystals B) clays crystallize to micas, forming a highly foliated, mica-rich rock C) limestone grains react to form quartz and feldspars D) calcite grains grow larger and increase in size

calcite grains grow larger and increase in size

31) When a radioactive isotope decays by electron capture, the electron ________. 31) _____ A) combines with a neutron in the nucleus, raising the mass number of the daughter isotope by one B) makes the parent isotope into an ion with a charge of negative one C) combines with a proton in the nucleus; the atomic number of the daughter is one less than the parent D) makes the daughter isotope into an ion with a charge of positive one

combines with a proton in the nucleus; the atomic number of the daughter is one less than the parent

34) Brittle deformation would be favored over plastic deformation in which of the following conditions? A) high confining pressures B) warmer temperatures C) shallow depths D) cooler temperatures

cooler temperatures

32) What is the source of natural carbon-14? 32) _____ A) leakage of radioactive gases from the liquid, outer core B) fusion of hydrogen and helium in the Sun and eruption of solar flares C) nuclear fission of the heavy, radioactive elements uranium and thorium D) cosmic ray collisions and neutron-capture involving atmospheric nitrogen

cosmic ray collisions and neutron-capture involving atmospheric nitrogen

46) Energy is stored in rocks adjacent to the site of a future earthquake as ________. A) elastic strain B) plastic strain C) thermal energy D) plastic flow energy

elastic strain

27) Which of the following denotes the divisions of the geologic time scale in correct order of decreasing lengths of time beginning with the longest time interval and ending with the shortest? 27) _____ A) eon, era, period, epoch B) era, period, epoch, eon C) eon, epoch, period, era D) eon, era, epoch, period

eon, era, period, epoch

28) The rare element iridium has been implicated in which "ancient health" crisis?28) _____ A) disappearance of Neanderthal man during the early Cenozoic era B) extinction of the woolly mammoths in late Pleistocene time C) extinction of the dinosaurs at the end of the Cretaceous Period D) poisoning of primitive algae in the Hadean and Archean eons

extinction of the dinosaurs at the end of the Cretaceous Period

53) The Earth's magnetic field ________. 53) _____ A) results from self-induction of rising magmas in the asthenosphere B) is a permanent field due to magnetized, iron-rich, mineral grains in the oceanic lithosphere C) is a high temperature superconductor in the inner core D) is a self-generating and self-reversing dynamo in the outer core

is a self-generating and self-reversing dynamo in the outer core

17) Which of the following rocks would exhibit visible, textural evidence of having undergone some partial melting? 17) _____ A) slate B) migmatite C) fault breccia D) foliated hornfels

migmatite (rocks formed in melting place)

48) The ________ of the Earth does not transmit S waves. 48) _____ A) inner crust B) outer mantle C) outer core D) deep mantle

outer core

19) What foliated, metamorphic rock is texturally intermediate between slate and schist? A) gneiss B) phyllite C) fault breccia D) quartzite

phyllite

29) The ________ is the idea or concept that ancient life forms succeeded each other in a definite, evolutionary pattern and that the contained assemblage of fossils can determine geologic ages of strata? 29) _____ A) law of fossil regression B) law of correlative indexing C) principle of faunal successionD) principle of cross correlation

principle of faunal succession

22) Which of the following lists the rocks in the order of increasing grain size and increasing grade of metamorphism? 22) _____ A) slate, phyllite, schist B) phyllite, slate, schist C) schist, slate, phyllite D) slate, schist, phyllite

slate, phyllite, schist

33) Which one of the following would not be a characteristic of the San Andreas fault zone? A) laterally offset stream channels B) steep, near vertical, dip-slip, fault scarps C) deformed, broken, and pulverized bedrock D) sag ponds

steep, near vertical, dip-slip, fault scarps

44) On a typical seismogram, ________ will show the highest amplitudes.44) _____ A) surface waves B) P waves C) body waves D) S waves

surface waves

36) A reverse fault is one in which ________. 36) _____ A) one block has moved downward and the other moved horizontally along a vertical fault B) the hanging wall block has moved up relative to the footwall block along an inclined fault C) the block above the fault plane has moved backwards with respect to the other block D) both blocks have moved horizontally in opposite directions along an inclined fault

the hanging wall block has moved up relative to the footwall block along an inclined fault