Exam 1

A ______ is an intrusive structure that formed from magma that solidified within the "throat" of a volcano. A. volcanic neck B. sill C. laccolith D. batholith E. diaper

A

Crystal settling accounts for important deposits of ______. A. chromium and platinum B. gold C. lead and zinc D. iron E. aluminum and silicon

A

Fine-grained igneous rocks (grains < 1.0 mm) that have small grains cooled rapidly and are likely to be _______. A. extrusive B. reclusive C. intrusive D. obtrusive E. preclusive

A

Igneous rocks that are silica-rich with high aluminum, sodium, and potassium are _____ rocks. A. silicic B. ultramafic C. mafic D. extraterrestrial E. intermediate

A

Most of the basalt and gabbro on the ocean floor is created at mid oceanic ridges, which are also ____. A. divergent plate boundaries B. ocean-ocean convergent plate boundaries C. transform plate boundaries D. ocean-continent plate boundaries E. intraplate igneous areas

A

Specific gravity is the ratio of the mass of a mineral to the mass of an equal volume of __. A. liquid water B. solid water C. quartz D. diamond E. air

A

The ______ group of minerals is characterized by two parallel chains of silica tetrahedra in their structure. A. amphibole B. feldspar C. olivine D. pyroxene E. mica (biotite, muscovite, etc.)

A

The mineral ___ reacts with weak hydrochloric acid to produce carbon dioxide gas, i.e., it effervesces (fizzes) in dilute acid. A. calcite B. feldspar C. quartz D. biotite E. amphibole

A

The most common minerals in the Earth's crust are the _______. A. silicates B. carbonates C. halides D. sulfides E. sulfates

A

What is the process through which magma differentiation takes place? A. crystal settling B. partial melting C. viscosity of the magma D. heating of the country rock E. subduction

A

What type of melting takes place when a body of hot mantle rock moves upward and the pressure is reducted to the extent that the melting point drops to the temperature of the body? A. decompression melting B. subduction melting C. depressurized melting D. exfoliational melting E. mantle plume melting

A

___ is a sedimentary rock formed by the cementation of coarse angular fragments of rubble. A. Breccia B. Conglomerate C. Boulder rock D. Arkose E. Cataclastic

A

____ is the most common element in the Earth's crust. A. Oxygen B. Iron C. Magnesium D. Hydrogen E. Fluorine

A

____ 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

_____ is the ability of a mineral to break, when struck or split, along preferred planar directions. A. Cleavage B. Crystal form C. Facets D. Planes E. Form

A

_______ sediments are deposited or precipitated as a result of the actions of organisms. A. Biochemical B. Pyroclastic C. Hyaloclastic D. Siliciclastic E. Calciclastic

A

A sedimentary rock that consists of sediment grains bound by cement into a rigid framework is called _______. A. crystalline B. clastic C. biochemical D. organic E. recycled

B

Both andesite and ___ are composed of feldspars and 30% to 50% ferromagnesian minerals. A. granite B. diorite C. pegmatite D. gabbro E. rhyolite

B

Imagine two magmas that are identical in all respects (for example, same chemistry, pressure, volume) except that one magma is hotter than the other. Which magma will have the higher viscosity? A. The hotter magma will be more viscous. B. The cooler magma will be more viscous. C. The magmas will have the same viscosity. D. There is not sufficient information to establish the relative viscosities of these magmas. E. Temperature does not affect magma viscosity.

B

Non-silicate minerals include the halides like _____. A. calcite B. halite C. magnetite D. pyrite E. gypsum

B

The coarse-grained equivalent of basalt is a(n) ______. A. andesite B. gabbro C. granite D. diorite E. rhyolite

B

The first plagioclase crystals to form as a hot melt cools are high in ______. A. iron B. calcium C. manganese D. carbonate E. lead

B

The hardest mineral has a hardness of ___ on Mohs' relative hardness scale. A. 1 B. 10 C. 100 D. 1000 E. 10000

B

The softest mineral on Mohs' hardness scale is ____. A. gypsum B. talc C. diamond D. quartz E. mica

B

The third most abundant element in the Earth's crust is ______; it is more common than iron. A. magnesium B. aluminum C. calcium D. fluorine E. tin

B

Viscosity is a property of a fluid that relates to how easily the fluid flows. A material that is viscous __. A. flows easily B. flows less easily C. is always hot D. is always a solid E. is always cold

B

When seawater evaporates, its sodium and chlorine are electronically attracted to one another and crystallize into ___. A. quartz B. halite C. clay D. calcite E. hematite

B

___ are features found within sedimentary rock that formed during or shortly after deposition. A. Bedding planes B. Sedimentary structures C. Laminations D. Formations E. Turbidity currents

B

___ is a coarse-grained igneous rock (grains > 1 mm diameter) with visible grains of quartz. A. Gabbro B. Granite C. Basalt D. Peridotite E. Andesite

B

___, a Danish naturalist, was the first to note that the angle between two adjacent faces of a crystal of quartz is always exactly the same. A. Einstein B. Steno C. Plummer D. McGeary E. Carlson

B

______ is the predominant igneous rock of the continents. A. Basalt B. Granite C. Rhyolite D. Gabbro E. Limestone

B

_______ are the smallest electrically neutral assemblies of matter and energy that we know of in the universe. A. Isotopes B. Atoms C. Ions D. Electrons E. Protons

B

________ lava is largely restricted to narrow zones along convergent plate boundaries. A. Granite B. Andesite C. Rhyolite D. Ultramafic E. Carbonate

B

A pulverized mineral (usually on a piece of white unglazed porcelain) gives a color called its ____, that is usually more reliable than the color of the specimen itself. A. dust B. chroma C. streak D. smear E. powder

C

A(n) ____ is a body of sediment deposited when a river flows into standing water, like a lake or sea. A. formation B. alluvial fan C. delta D. sandbar E. intrusive deposit

C

Asymmetrical _____ are produced by current flowing in a single direction. A. wave marks B. ridge marks C. ripple marks D. mullion marks E. burrow marks

C

Calcite has ___ direction of cleavage. A. 1 B. 2 C. 3 D. 4 E. 6

C

Hawaii and __________ eruptions are related to intraplate igneous activity. A. Japan B. Cascade C. Yellowstone D. Honduras E. California

C

Igneous rocks may be either ____ if they form on or near Earth's surface, or ___ if they solidify under ground. A. intrusive; volcanic B. volcanic; extrusive C. extrusive; intrusive D. plutonic; intrusive E. intrusive; extrusive

C

Mafic magma generated in the _______ rises to the base of the crust. A. continental crust B. outer core C. asthenosphere D. spreading ridges E. mantle plumes

C

Oil and natural gas originate from _____ in marine sediments. A. peat B. the earth's interior C. organic matter D. coal E. comet impacts

C

On Mohs' scale of hardness your fingernail has a value of ____. A. 12 B. 5 C. 21⁄2 D. 61⁄2 E. 9

C

Sedimentary rock on ____ will enable planetary geologists to one day unravel its history. A. the moon B. Jupiter C. Mars D. Mercury E. Io

C

Silt is mostly composed of ___ grains. A. clay mineral B. feldspar C. quartz D. mica E. calcite

C

The atomic number of an element equals the number of _____ in each atom. A. electrons B. neutrons C. protons D. Answers neutrons and protons are both correct; answer a is not correct. E. Answers electrons, neutrons and protons are all correct.

C

The common mineral ___ is an example of an isolated silica tetrahedron structure. A. amphibole B. feldspar C. olivine D. pyroxene E. mica (biotite, muscovite, etc.)

C

The melting point of a mineral generally _____ with increasing pressure (or depth). A. does not change B. decreases C. increases D. becomes dependent on rock type E. is unknown

C

The mineral ___ is strongly magnetic. A. calcite B. pyrite C. magnetite D. magnesite E. quartz

C

The most common cements are _____ and ____. A. hematite; limonite B. dolomite; halite C. calcite; quartz D. olivine; pyroxene E. feldspar; mica

C

The most common minerals in a granite are the ______. A. oxides B. carbonates C. feldspars D. ferromagnesians E. micas

C

To explain the great volumes of granite plutonic rocks, most geologists think that partial melting of the _______ must take place. A. core B. lower mantle C. lower continental crust D. oceanic crust E. asthenosphere

C

Two examples of framework silicates are _____ and ______. A. calcite; dolomite B. olivine; pyroxene C. quartz; feldspar D. biotite; muscovite E. amphibole; olivine

C

Ultramafic igneous rocks are composed almost entirely of __. A. feldspar B. quartz C. ferromagnesian minerals D. calcite E. diamonds

C

___ is a hard, compact, very fine-grained sedimentary rock composed entirely of silica. A. Tuff B. Chalk C. Chert D. Travertine E. Claystone

C

_____ form(s) only in fine-grained sediments that are exposed to air. A. Cross beds B. Cleavage C. Mudcracks D. Bedding E. Ripples

C

_____ igneous rocks, like gabbro and basalt, are silica-deficient with high magnesium and iron. A. Felsic/silicic B. Intermediate C. Mafic D. Intrusive E. Extrusive

C

______ 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

_______ and sapphire are both varieties of the common mineral corundum. A. Emerald B. Turquoise C. Ruby D. Beryl E. Peridot

C

A _____ is a layer of sedimentary rock with a vertical change in particle size, usually from coarse at the bottom to fine at the top. A. patterned bed B. cross bed C. sorted bed D. graded bed E. schist

D

A _______ is a tabular (thin but large area) intrusive body that is concordant (parallel to the host rock structure). A. dike B. mantle C. threshold D. sill E. neck

D

A silica tetrahedron is composed of four atoms of the element ___ and one atom of __. A. silicon; aluminum B. silicon; oxygen C. silicon; iron D. oxygen; silicon E. aluminum; silicon

D

A useful tool illustrating the relationships among igneous, sedimentary, and metamorphic rocks is called the ___. A. weathering and erosion of surface features B. plate tectonic cycle C. relationships between preexisting rock D. rock cycle E. Bowen's reaction series

D

A(n) ___ is a body of rock of considerable thickness that is large enough to be mappable and with characteristics that distinguish it from adjacent rocks. A. layer B. bed C. blanket D. formation E. epoch

D

Continental environments include all of the following except __. A. lake beds B. river beds C. glacial deposits D. coral reefs E. alluvial fans

D

Five of the six minerals collectively known as asbestos contain single chains of silica tetrahedral and belong to the _______. A. amphiboles B. feldspars C. olivines D. pyroxenes E. micas

D

Granite and ______ are composed predominantly of feldspar and quartz. A. oceanic crust B. diorite C. basalt D. rhyolite E. ultramafics

D

How is a sill different from a dike? A. The sill is tabular in shape. B. Dikes are intrusive structures. C. Dikes are fine-grained and sills are coarse-grained. D. Sills are parallel to the layering in the country rock. E. A sill is shaped like a mattress, while a dike is shaped like a pillow.

D

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

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

Mineralogically and chemically equivalent rocks are ___ and __. A. granite; rhyolite B. gabbro; basalt C. diorite; andesite D. mafic; ultramafic E. intermediate; felsic

D

On its slow journey through the crust, mafic magma evolves into intermediate magma by differentiation and assimilation of ______. A. mantle rocks B. basalt C. gabbro D. silicic rocks

D

Plagioclase feldspar commonly exhibits __, straight, parallel lines on the flat surfaces of one of the two cleavage directions. A. parallelograms B. grooves C. lamitations D. striations E. laminations

D

Rock salt is composed of the mineral ______. A. calcite B. trona C. dolomite D. halite E. gypsum

D

Sand grains can be distinguished from silt grain by ____. A. the gritty feel between the teeth B. seeing the individual sand grains C. composition of the grains D. the gritty feel between the fingers. E. only by a microscope

D

The _____ group and the ___ group are sheet silicates characterized by one direction of cleavage. A. amphibole; pyroxene B. feldspar; quartz C. olivine; plagioclase D. mica; clay E. carbonate; sulfide

D

The atomic mass number of an atom is the total number of ___ in the atom. A. electrons B. neutrons C. protons D. protons and neutrons E. protons, neutrons, and electrons

D

The crust beneath the world's oceans is mafic ________. A. iron B. asthenosphere C. granite and rhyolite D. basalt and gabbro E. Answers iron, asthenosphere, and granite and rhyolite are all correct.

D

The geothermal gradient, on average, is about _____. A. 0.004C/km B. 2.5C/km C. 25C/km D. 30C/km E. 2500C/km

D

The mineral ___ is an example of a native element. A. quartz B. feldspar C. calcite D. graphite E. halite

D

The two primary types of carbonate sedimentary rocks are ___ and dolostone. A. dolomite B. gypsum C. coal D. limestone E. sandstone

D

Under what conditions is a sediment considered to be well-sorted? A. when the grains contains a wide variety of grain sizes mixed together B. when the grains contains just one general grain size and one mineral C. when the grains are in individual layers D. when the grains are nearly all the same size E. when the grains contain just one or two general grain sizes

D

What is the sequence of crystallization along the discontinuous branch of Bowen's reaction series? A. sodium-rich to calcium-rich plagioclase B. quartz, potassium feldspar, biotite C. silicic, felsic, mafic, intermediate D. olivine, pyroxene, amphibole, biotite E. framework, double chain, single chain, sheet, isolated

D

What is the special property of the mineral halite? A. It has 5 directions of cleavage. B. It has a hardness of -3. C. It can transmit electricity. D. It tastes like salt. E. It has an extremely high melting temperature.

D

___ are igneous rocks that are silica-deficient but high in iron and magnesium. A. Felsic B. Intermediate C. Oxide D. Mafic E. Sulfate

D

___ 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

_____ are fragments of country rock that are distinct from the body of igneous rocks in which they are enclosed. A. Clasts B. Chill zones C. Phenocrysts D. Xenoliths E. Necks

D

_____ are massive deposits of limestone. A. Turbidity flows B. Alluvial fans C. Deltas D. Reefs E. Lithosomes

D

_____ is an expansive (swells when wet) clay mineral. A. Quartz B. Olivine C. Pyroxene D. Montmorillonite E. Mica

D

_____, a coarse-grained rock composed of pyroxene and olivine, is the most abundant ultramafic rock. A. Diorite B. Gabbro C. Granite D. Peridotite E. Hematite

D

______ are extremely coarse-grained with crystal up to 10 meters across. A. Granites B. Ultramafic C. Basalts D. Pegmatites E. Marbles

D

______ is the general term for the processes that convert loose sediment into sedimentary rock. A. Gluing B. Hardening C. Crystallization D. Lithification E. Stiffening

D

______ is the shift to a tighter packing of sediment grains due to the weight of overburden. A. Cementation B. Recrystallization C. Preservation D. Compaction E. Deposition

D

______ of an element are atoms containing different numbers of neutrons but the same number of protons. A. Ions B. Classes C. Particles D. Isotopes E. Varieties

D

_______ 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

A(n) ___ is sandstone containing a significant amount of feldspar. A. marble B. quartz sandstone C. graywacke D. shale E. arkose

E

In order for a particular type of material to be classified as a mineral, it must ____. A. be a solid B. occur naturally C. have a crystalline structure D. have a definite chemical composition E. All of the answers are correct.

E

In some minerals the bonds are equally strong in all directions, therefore they have no cleavage but instead _____ along irregular surfaces that are commonly curved. A. luminesce B. chip C. flatten D. bend E. fracture

E

Some minerals have the same chemical composition but different crystal structures, a phenomenon termed _______. A. alteration B. recrystallization C. metamorphism D. isotopes E. polymorphism

E

The _____ group of minerals are sheet silicates. A. amphibole B. feldspar C. olivine D. pyroxene E. mica

E

The two most abundant elements in Earth's crust are __. A. iron and magnesium B. carbon and hydrogen C. carbon and oxygen D. hydrogen and oxygen E. oxygen and silicon

E

Under ideal conditions rock can melt and yield a granite composition at temperatures as low as ___. A. 100 Celsius B. 225 Celsius C. 333 Celsius D. 450 Celsius E. 650 Celsius

E

___ has the property of generating electricity when squeezed in a certain crystallographic direction. A. Copper B. Mica C. Amphibole D. Gold E. Quartz

E

____ elements make up 98% of the Earth's crust. A. Fourteen B. Ninety-two C. Two D. Twenty E. Eight

E

____ rocks have coarse crystals in a fine-grained matrix. A. Ultramafic B. Granite C. Sill D. Pegmatite E. Porphyritic

E

_____ 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

_____ is a term that describes a series of visible layers in sedimentary rock. A. Units B. Tables C. Sheets D. Planes E. Bedding

E

______ forms from limestone when the calcium in calcite is partially replaced by magnesium. A. Gypsum B. Halite C. Chert D. Quartz E. Dolomite

E