Geology Exam 1

43) At low pressures and in the absence of water, rhyolites and granites begin to melt at about ________. A) 800o C B) 300o C C) 6000o F D) 500o F

A) 800o C

23)________ tend to increase the explosive potential of a magma body beneath a volcano. A) High viscosity and dissolved gas B) Low viscosity; low dissolved gas content C) Low silica content, low viscosity D) High viscosity; low dissolved gas content

A) High viscosity and dissolved gas

4) Volcanic bombs originate ________. A) as erupted magma blobs that partly congeal before falling to the ground B) as blocks of volcanic rock ejected from an erupting volcanic crater C) as laser-guided, granite blocks launched from a supersonic jet D) as ash particles that join together in the eruptive plume and fall as cobble-sized objects

A) as erupted magma blobs that partly congeal before falling to the ground

7) Which carbonate mineral reacts readily with cool, dilute hydrochloric acid to produce visible bubbles of carbon dioxide gas? A) calcite B) Plagioclase C) dolomite D) quartz

A) calcite

29) An atom's mass number is 13 and its atomic number is 6. How many neutrons are in its nucleus? A)7 B) 19 C) 6 D) 13

A)7

16) Which one of the following is a typical product of weathering? A)Clays B) feldspars C) micas D) ferromagnesians

A)Clays

6)A ________ is a well-tested and widely accepted view that best explains certain scientific observations. A)Theory B)Law C)Hypothesis D)generalization

A)Theory

14) Which of the following best characterizes ferromagnesian silicates? A)They are black to dark-green, silicate minerals containing iron and magnesium. B) They contain iron and magnetite, are black in color, and they have metallic lusters. C) They contain magnetite and ferroite and they are clear to light green. D) They are mostly clear, colorless, and rich in the elements magnesium and ferrium.

A)They are black to dark-green, silicate minerals containing iron and magnesium.

30) Which one of the following is not true for minerals? A)They can be a liquid, solid, or gas. B) They have a specific, internal, crystalline structure. C) They have a specific, predictable chemical composition. D) They can be identified by characteristic physical properties.

A)They can be a liquid, solid, or gas.

27) The strong tendency of certain minerals to break along smooth, parallel planes is known as ________. A)cleavage B) crystal form C) cracking luster D) streak

A)cleavage

Consider the Bowen's reaction series. Which mineral would you expect to see as a phenocryst in a porphyritic basalt? A. Olivine B. Quartz C. Orthoclase D. Sodium-rich plagioclase

A. Olivine

________ is the dominant feldspar in basalt. A. Plagioclase B. Microline C. Orthoclase D. Pyroxene

A. Plagioclase

9) The ________ ocean basin is rimmed by the most subduction zones. A) Arctic B) Pacific C) Indian D) Atlantic

B) Pacific

2) Which of the following is not a fundamental particle found in atoms? A)Electron B) Selectron C) Neutron D) protons

B) Selectron

5) Which of the following is correct for isotopes of the same element? A)The atoms have the same number of electrons and different numbers of protons. B) The atoms have different numbers of neutrons and the same number of protons. C) The atoms have different numbers of protons and the same number of neutrons. D) The atoms have different numbers of electrons but the same number of neutrons.

B) The atoms have different numbers of neutrons and the same number of protons.

16) ________ are usually the most abundant gases emitted during basaltic volcanism. A) Neon and ammonia B) Water and carbon dioxide C) Oxygen and nitrogen D) Chlorine and sodium

B) Water and carbon dioxide

20) Which of the following diseases has been linked directly to prolonged inhalation of asbestos dust? A)diabetes B) lung cancer C) glaucoma D) muscular dystrophy

B) lung cancer

46) Why do magmas rise toward Earth's surface? A) most magmas are richer in silica than most crustal and upper mantle rocks B) magmas are mainly liquid and contain dissolved fluids such as water; most are less dense than the adjacent solid rock C) magmas are more viscous than solid rocks in the crust and upper mantle D) all of the above

B) magmas are mainly liquid and contain dissolved fluids such as water; most are less dense than the adjacent solid rock

13) Which of the following minerals is in the mineral group known as mica? A)augite B) muscovite C) olivine D) orthoclase

B) muscovite

26) What element is the most abundant in the Earth's crust by weight? A)Carbon B) oxygen C) chlorine D) sodium

B) oxygen

8) Which mineral is composed of silicon dioxide (Si02)? A)diamond B) quartz C) calcite D) olivine

B) quartz

30) Which one of the following statements is not true? A) basalt magmas in general have higher temperatures than rhyolite magmas B) when magma reaches the surface, its dissolved gas content increases C) melting temperatures of silicate rocks are lowered by small amounts of water D) melting temperatures of silicate rocks increase with increased pressure

B) when magma reaches the surface, its dissolved gas content increases

1) The currently accepted age of Earth is ________ years. A)6.4 trillion B)4.6 billion C)4.6 thousand D)6.4 million

B)4.6 billion

5)________ was an important 18th century English geologist and proponent of uniformitarianism. A)James Ussher B)James Hutton C)Charles Lyell D)Isaac Newton

B)James Hutton

7)Which of the following best defines a mineral and a rock? A)a mineral consists of its constituent atoms arranged in a geometrically repetitive structure; in a rock, the atoms are randomly bonded without any geometric pattern B)in a mineral the constituent atoms are bonded in a regular, repetitive, internal structure; a rock is a lithified or consolidated aggregate of different mineral grains C)a rock has an orderly, repetitive, geometrical, internal arrangement of minerals; a mineral is a lithified or consolidated aggregate of rocks D)a rock consists of atoms bonded in a regular, geometrically predictable arrangement; a mineral is a consolidated aggregate of different rock particles

B)in a mineral the constituent atoms are bonded in a regular, repetitive, internal structure; a rock is a lithified or consolidated aggregate of different mineral grains

4)Which one of the following observations and inferences is consistent with the idea of uniformitarianism? A)lava flows on the seafloor precipitated from seawater B)sand rolling along a stream bottom shows that sediment is moving downstream C)erupting volcanoes overlie burning, subterranean, coal beds D)all of the above

B)sand rolling along a stream bottom shows that sediment is moving downstream

Which one of the following describes a mineral's response to mechanical impact? A. Luster B. Cleavage C. Streak D. Crystal form

B. Cleavage

Which of the following minerals is a silicate? A. Hematite B. Muscovite C. Calcite D. Halite

B. Muscovite

A ________ is an open cavity in a volcanic rock that was filled by a gas bubble when the lava was still mainly liquid? A. Porphyrocryst B. Vesicle C. Phenocryst D. Xenocryst

B. Vesicle

17) The ion at the center of a silicate tetrahedron is surrounded by ________. A)6 oxygen ions B) 6 sodium ions C) 4 oxygen ions D) 4 sodium ions

C) 4 oxygen ions

4) Which of the following is an accurate description of ionic bonding? A) Nuclei of two different atoms share electrons, and the resulting compound is tightly bonded by the very strong, induced, electronuclear bonds. B) Nuclei of bonding atoms exchange electrons; the resulting ions are bonded together by the attractive forces between the negative and positive nucleons. C) Atoms of different elements, having gained or lost electrons, form negative and positive ions that are bonded together by attractive forces between ions with opposite charges. D) Atoms of two different elements share electrons and protons; the resulting compound is bonded together by the strong, binding energy of shared protons.

C) Atoms of different elements, having gained or lost electrons, form negative and positive ions that are bonded together by attractive forces between ions with opposite charges.

24) Which type of basaltic lava flow has its surface covered with sharp-edged, angular blocks and rubble? A) pillow lava B) pahoehoe C) aa D) scoria

C) aa

18) Which one of the following describes a mineralʹs response to mechanical impact? A)luster B) streak C) cleavage D) crystal form

C) cleavage

6) What mineral is the hardest known substance in nature? A) silicate B) muscovite C) diamond D) native gold

C) diamond

15) Which one of the following mineral groups exhibits a sheet-like silicate structure? A)pyroxenes B) carbonates C) feldspars D) clays

C) feldspars

10) A cubic centimeter of quartz, olivine, and gold weigh 2.5, 3.0, and 19.8 grams respectively. This indicates that ________. A)gold and olivine are silicates, quartz is elemental silicon B) gold is 6 to 7 times harder than olivine and quartz C) gold has a higher density and specific gravity than quartz and olivine D) olivine and quartz powders are harder than metallic gold

C) gold has a higher density and specific gravity than quartz and olivine

25) Which mineral is easily soluble in water at room temperature conditions? A)olivine B) Diamond C) halite D) talc

C) halite

12) Which of the following minerals is a ferromagnesian silicate? A)Quartz B) orthoclase C) muscovite D) hornblende

C) muscovite

2) Which type of basaltic lava flow has a fairly smooth, unfragmented, ropy surface? A) pegmatitic B) aa C) pahoehoe D) scoria

C) pahoehoe

11) Which one of the following is a sodium and calcium feldspar with twinning striations? A)Sanidine B) orthoclase C) plagioclase D) Microcline

C) plagioclase

36) A ________ volcano is a very large, gently sloping mound composed mainly of basaltic lava flows. A) cinder cone B) stratospheric C) shield D) composite

C) shield

38) Which region has the greatest concentration of currently active volcanoes? A) the coastal plain of western Africa B) European Russia and Siberia C) the circum-Pacific area D) the area surrounding the Red Sea

C) the circum-Pacific area

11)Which of the following is associated with deep mantle hot spots? A) the very young cinder cones scattered across the southwestern United States B) Vesuvius and the other volcanoes of Italy C) the volcanoes of Hawaii and Quaternary activity in Yellowstone National Park D) Mt. St. Helens and other volcanoes of the Cascade Mountains

C) the volcanoes of Hawaii and Quaternary activity in Yellowstone National Park

2)What are the basic differences between the disciplines of physical and historical geology? A)physical geology involves the study of rock strata, fossils, and deposition in relation to plate movements in the geologic past; historical geology charts how and where the plates were moving in the past B)physical geology is the study of fossils and sequences of rock strata; historical geology is the study of how rocks and minerals were used in the past C)historical geology involves the study of rock strata, fossils, and geologic events, utilizing the geologic time scale as a reference; physical geology includes the study of how rocks form and of how erosion shapes the land surface D)none of the above - physical geology and historical geology are essentially the same

C)historical geology involves the study of rock strata, fossils, and geologic events, utilizing the geologic time scale as a reference; physical geology includes the study

What element is the most abundant in the Earth's crust by weight? A. Carbon B. Chlorine C. Oxygen D. Sodium

C. Oxygen

________ is characterized by very coarse mineral grains? A. Obsidian B. Pumice C. Pegmatite D. Granite

C. Pegmatite

7) ________ magma is the most abundant type of erupted at oceanic spreading centers. A) Pegmatitic B) Granitic C) Andesitic D) Basaltic

D) Basaltic

3) ________ is a major dissolved volatile constituent in both magmas and volcanic gases? A) Hydrogen chloride B) Carbon monoxide C) Methane D) Water

D) Water

35) The average composition of rocks comprising a large composite cone or stratovolcano is similar to a (an) ________ magma. A) rhyolitic B) ultramafic C) basaltic D) andesitic

D) andesitic

28) What in the name given to an atom that gains or loses electrons in a chemical reaction? A)isotope B) nucleon C) molecule D) ion

D) ion

3)The ________ forms the relatively cool, brittle plates of plate tectonics. A) Eosphere B) Astrosphere C) Asthenosphere D) lithosphere

D) lithosphere

3) Atoms of the same element, zinc for example, have the same number of ________. A)electrons in the valence bond level B) neutrons in the outer nuclear shell C) electrons in the nucleus D) protons in the nucleus

D) protons in the nucleus

45) Which one of the following shows the correct order (left to right) of decreasing magma viscosity? A) andesite, rhyolite, basalt B) basalt, andesite, rhyolite C) basalt, rhyolite, andesite D) rhyolite, andesite, basalt

D) rhyolite, andesite, basalt

31) Which kind of volcanism is typical of mid-oceanic ridge systems? A) explosive; composite cones B) explosive; rhyolitic, pyroclastic flows C) fissure eruptions; flood basalts fields D) submarine; basaltic lava flows

D) submarine; basaltic lava flows

40) The Icelandic volcanoes are related to plate tectonics because ________. A) they lie on a spreading center where two plates are converging B) they lie on a subduction zone where two plates are converging C) they lie along a subduction zone where two plates are diverging D) they lie on a spreading center where two plates are moving apart

D) they lie on a spreading center where two plates are moving apart

9)Atoms of the same element, zinc for example, have the same number of ________. A)neutrons in the outer nuclear shell B)electrons in the nucleus C)electrons in the valence bond level D)protons in the nucleus

D)protons in the nucleus

________ is a volcanic rock that is extremely vesicular and glassy. A. Obsidian B. Pegmatite C. Tuff D. Pumice

D. Pumice

________ rocks always originate at the surface of the solid Earth. A. Secondary B. Igneous C. Metamorphic D. Sedimentary

D. Sedimentary

All silicate minerals contain which two elements? A. Iron, Silicon B. Silicon, Sodium C. Oxygen, Carbon D. Silicon, Oxygen

D. Silicon, Oxygen