Transcript
The Earth Through Time
Chapter 4—Rocks and Minerals: Documents that record Earth’s History
Multiple Choice Questions
Select the best answer.
1. What message can minerals provide about the history of the Earth?
a. Color.
b. Streak.
c. Paleomagnatism.
d. Age of the Earth.
e. Both c. and d.
2. Which of the following is not a mineral?
a. Glass.
b. Quartz.
c. Orthoclase.
d. Mica.
e. All of the above.
3. To qualify as a mineral which of the following must be true?
a. Naturally occurring.
b. Inorganic.
c. Crystalline.
d. Specific chemical composition.
e. All the above.
4. Why should color be used in conjunction with other physical property to identify a mineral?
a. The shape of a mineral can change its color.
b. Trace impurity in a mineral can influence the color.
c. Some minerals do not have color.
d. Color is not a physical property of a mineral.
e. Both a. and d.
5. What is the term for the quality of reflected light off a mineral surface?
a. Color.
b. Streak.
c. Hardness.
d. Luster.
e. Density.
6. Which of the following is a unit of density?
a. Grams/meter cubed.
b. Meter cubed/gram.
c. Gallon/slug.
d. Pound/inch.
e. Kilogram/centimeter squared.
7. What is the most common group of minerals in the Earth’s crust?
a. Carbonates.
b. Evaporites.
c. Silicates.
d. Natives.
e. Sulfates.
8. What is the most abundant element in the Earth’s crust?
a. Iron.
b. Silicon.
c. Calcium.
d. Potassium.
e. Oxygen.
9. What the name of the most common mineral group in the Earth’s crust?
a. Quartz.
b. Mica.
c. Olivine
d. Feldspar.
e. Amphibole.
10. Why are some varieties of quartz called chert?
a. Color.
b. Sub-microscopic crystal size.
c. Igneous origins.
d. Metamorphic origins.
e. Both c. and d.
11. Which feldspar mineral contains potassium?
a. Orthoclase.
b. Plagioclase.
c. Quartz.
d. Biotite.
e. Augite.
12. Micas are characterized by which of the following physical properties?
a. Cleavage.
b. Color.
c. Density.
d. Luster.
e. Hardness.
13. The difference between diorite and andesite is
a. texture.
b. mineral composition.
c. lack of crystals.
d. silica content.
e. texture and composition.
14. Which of the following minerals belongs to the ferromagnesian group?
a. Augite.
b. Orthoclase.
c. Quartz.
d. Olivine.
e. Both a. and d.
15. Which of the following minerals is common in the upper mantle?
a. Biotite.
b. Orthoclase.
c. Quartz.
d. Muscovite.
e. Olivine.
16. A mineral in the discontinuous side of Bowen’s reaction series is
a. olivine.
b. plagioclase.
c. pyroxene.
d. hornblende.
e. All but b.
17. The mineral pair calcite and aragonite are chemically identical, but structurally different. What is the name for this type of mineral pair?
a. Matched.
b. Polymorph.
c. Monomorph.
d. Symetric.
e. none of the above.
18. The magma generated by partial melting basalt is called _________.
a. Basalt.
b. Andesite.
c. Gabbro.
d. Granite.
e. Rhyolite.
19. What is the name of the rock type formed from a molten state?
a. Rock gypsum.
b. Metamorphic.
c. Sedimentary.
d. Igneous.
e. Conglomerate.
20. What process is required to convert an igneous rock to sediment?
a. Metamorphism.
b. Weathering.
c. Lithification.
d. Melting.
e. Solidification.
21. Rock groups are organized based on their origins while individual rocks are identified by ________ and composition.
a. Mineralogy.
b. Pressure.
c. Temperature.
d. Texture.
e. Melting.
22. Carbonate spheres in limestone form a texture called __________.
a. carbonate clasts.
b. carbonate spar.
c. oölites.
d. micrite.
e. fossils.
23. Plutonic rocks form ____________ crystals.
a. Invisible.
b. Pink.
c. Visible.
d. Round.
e. Square.
24. What is the name of the igneous texture containing no minerals?
a. Course grained.
b. Fine grained.
c. Porphyritic.
d. Vesicular.
e. Glass.
25. As magma cool along the discontinuous branch of the Bowens’ Reaction Series which mineral will form after hornblende?
a. Quartz.
b. Olivine.
c. Boitite.
d. Plagioclase.
e. Clay.
26. Which of the following rock types has the highest viscosity as a melt?
a. Basalt
b. Rhyolite
c. Gabbro
d. Andesite
e. Schist
27. How could igneous activity play a role in mass extinction events?
a. Emission of ash, CO2, and other gases
b. Formation of mountains
c. Creation of ocean basins
d. Lava flows
e. None of the above
28. Sediments are converted into rocks by a process called ________.
a. Igneous intrusion.
b. Lithification.
c. Evaporation of sea water.
d. Transport of sediments.
e. Weathering of rocks.
29. Bedded chert deposits are associated with ___________.
a. Evaporites.
b. Volcanic activity.
c. Metamorphism.
d. Mountain building.
e. Trapped sea water.
30. One of the principle features of sedimentary rocks is _________.
a. being green in color.
b. being hard.
c. Iron formations.
d. Quarts.
e. Layers.
31. What rock type will be produced by the residual solid left behind after the chemical weathering of feldspar?
a. Arkose.
b. Quartz sandstone.
c. Shale.
d. Chert.
e. Greywacke.
32. Sedimentary rocks form on the Earth’s surface. As a consequence they are important in the recording of the ____________ of the Earth.
a. Core temperature.
b. Age.
c. Greenstone.
d. Paleoclimates.
e. Grade of metamorphism.
33. The formation of metamorphic rocks takes place while in the ___________.
a. Molten state.
b. Solid state.
c. Liquid state.
d. Gaseous state.
e. Vapor state.
34. Metamorphic rocks that have experienced primarily heat and not pressure are called ______.
a. Regional metamorphism.
b. Spatial metamorphism.
c. Contact metamorphism.
d. Elevated metamorphism.
e. Reduced metamorphism
35. Metamorphic rocks possessing a foliated texture have what characteristic?
a. Equal sized minerals.
b. Random distribution of mineral shapes.
c. Visible minerals.
d. All the same minerals.
e. Parallel mineral alignment
36. Which of the following metamorphic rocks possesses black and white banding?
a. Hornfels.
b. Greenstone.
c. Mica schist.
d. Marble.
e. Gneiss
37. Metamorphic rocks that form from the alteration of limestone are _____.
a. Quartzite
b. Marble
c. Greenstone
d. Slate
e. Phyllite
38. Calk is composed of _____________.
a. Trapped sea water.
b. Marine plankton.
c. Clam shells.
d. Fragments of basalt.
e. Vertebrate fossils.
39. Which of the following are favorable conditions for carbonate deposition?
a. Cold shallow seas.
b. Cold deep oceans.
c. Warm shallow seas.
d. Turbulent seas.
e. Streams and rivers.
40. Many regionally metamorphosed rocks were once ____________.
a. Roots of tall mountains.
b. Shallow basins.
c. Open plains.
d. Volcanoes.
e. All the above.
Answers to Questions
1. c 11. a 21. d 31. c
2. a 12. a 22. c 32. d
3. e 13. a 23. c 33. b
4. b 14. e 24. e 34. c
5. d 15. e 25. c 35. e
6. a 16. e 26. b 36. e
7. c 17. b 27. a 37. b
8. e 18. b 28. b 38. b
9. d 19. d 29. b 39. c
10. b 20. b 30. e 40. a
TEST 2
1. Earth's crustal rocks are dominated by which two elements?
a) iron and oxygen
b) silicon and oxygen
c) iron and magnesium
d) oxygen and aluminum
e) silicon and aluminum
Ans: b
Feedback: See page 53
2. What is the dominant mineral in the Earth's crust?
a) quartz
b) clay
c) feldspar
d) calcite
e) basalt
Ans: c
Feedback: See page 54
3. What is the mineral that is the main constituent of limestone and marble?
a) quartz
b) feldspar
c) calcite
d) clay
e) halite
Ans: c
Feedback: See page 56
4. The igneous, sedimentary, and metamorphic rocks may be changed into one another through processes such as melting, compression and alteration, or weathering and erosion. These changes are part of:
a) Bowen’s reaction series.
b) mineralization.
c) neptunism.
d) catastrophism.
e) rock cycle.
Ans: e
Feedback: See page 58
5. Rocks which have cooled from a molten state are referred to as:
a) carbonates.
b) metamorphic.
c) igneous.
d) sedimentary.
e) sandstones.
Ans: c
Feedback: See pages 58-59
6. Rocks which consist of weathered fragments of pre-existing rocks are called:
a) plutonic.
b) sedimentary.
c) igneous.
d) metamorphic.
e) extrusive.
Ans: b
Feedback: See pages 67-68
7. Rocks which have been changed by heat, pressure, and associated chemical activity are referred to as:
a) plutonic.
b) metamorphic.
c) igneous.
d) sedimentary.
e) extrusive.
Ans: b
Feedback: See page 72
8. Igneous rocks that cool slowly beneath the Earth's surface have:
a) small crystals.
b) large crystals.
c) large crystals in a fine-grained matrix.
d) glass but no crystals.
e) foliation.
Ans: b
Feedback: See page 59
9. The most abundant kind of volcanic rock, which underlies the ocean basins and comprises the Hawaiian islands is:
a) basalt.
b) rhyolite.
c) granite.
d) peridotite.
e) granodiorite.
Ans: a
Feedback: See pages 63 and 65
10. As feldspars weather, they form a mineral called:
a) quartz.
b) augite.
c) calcite.
d) clay.
e) olivine.
Ans: d
Feedback: See page 56
11. What is coal formed from?
a) sand grains
b) plant remains
c) carbonate minerals
d) extrusive igneous rocks
e) clay minerals
Ans: b
Feedback: See page 72
12. Which mineral reacts with hydrochloric acid to produce bubbles of CO2 gas?
a) anhydrite
b) gypsum
c) quartz
d) calcite
e) feldspar
Ans: d
Feedback: See page 57
13. What is the parallel alignment of flakes of mica in a rock, which is the result of directional pressure called?
a) clastic texture
b) foliation
c) crystalline texture
d) cleavage
e) stratification
Ans: b
Feedback: See page 73
14. When granite is weathered, this mineral will remain unaltered because it is relatively very resistant to weathering:
a) olivine.
b) feldspar.
c) quartz.
d) calcite.
e) pyroxene.
Ans: c
Feedback: See page 68
15. Which of these minerals formed by precipitattion from a body of water that evaporated?
a) quartz
b) dolomite
c) micas
d) halite
e) olivine
Ans: d
Feedback: See page 57
TEST 3
1. The rock cycle shows us that
a. metamorphic rocks can only be derived from igneous rocks.
b. metamorphic rocks are derived from magma.
c. any rock type can be derived from any other rock type.
d. igneous rocks are composed of quartz and gabbro.
2. A textural term used to describe an igneous rock with large crystals called phenocrysts in a matrix of more finely crystalline rock is
a. phenocryptic. c. porphyritic.
b. polymorphic. d. dolomitic.
3. Which of the following is a foliated metamorphic rock?
a. schist c. gabbro
b. shale d. marble
4. A carbonate mineral that occurs in a different crystal form and is less common than either calcite or dolomite is
a. aragonite. c. calcite.
b. gypsum. d. silica.
5. An example of a sedimentary evaporite is
a. calcite. c. limestone.
b. dolomite. d. gypsum.
6. Rocks that cool from a melt are
a. metamorphic rocks. d. hard rocks.
b. igneous rocks. e. on the rocks.
c. sedimentary rocks.
7. Rocks that have recrystallized under high temperatures and pressures are
a. metamorphic rocks. d. granite.
b. igneous rocks. e. basalt.
c. sedimentary rocks.
8. The size, shape, and arrangement of mineral grains in a rock constitutes its
a. permeable origin. c. cement.
b. porosity. d. texture.
9. A clastic rock composed of water-worn, rounded particles larger than 2 mm in diameter is
a. mudstone. c. breccia.
b. siltstone. d. conglomerate.
10. The overwhelmingly predominant constituent of an igneous rock is
a. silicon. c. aluminum.
b. oxygen. d. calcium.
11. Which of the following is one of the eight most common elements in the earth’s crust?
a. nitrogen d. thorium
b. potassium e. hydrogen
c. uranium
12. The fine extrusive equivalent of granite is
a. diorite. d. basalt.
b. rhyolite. e. gabbro.
c. andesite.
13. The ferromagnesium silicate mineral that occurs commonly in igneous and metamorphic rock is
a. amphibole. d. sylvite.
b. pyrite. e. goethite.
c. sphalerite.
14. An igneous rock that is an extrusive is
a. rhyolite. d. conglomerate.
b. gabbro. e. schist.
c. granite.
15. Because of its iron and magnesium content which one of the following is considered a ferromagnesium (mafic) mineral?
a. orthoclase c. hornblende
b. plagioclase d. obsidian
16. The elements that comprise 60% of earth’s crust and are silicates are called
a. dolomites. d. feldspars.
b. carbonates. e. quartz.
c. sulfates.
17. The most common extrusive rock composed of fine mineral crystals is
a. basalt. d. diorite.
b. gabbro. e. conglomerate.
c. rhyolite.
18. Diorite is a relatively coarse-grained intrusive igneous rock composed mainly of plagioclase feldspar. Its fine grained equivalent is
a. basalt. c. pumice.
b. andesite. d. rhyolite.
19. A biochemical rock made from microscopic nonsiliceous plant remains is
a. coal. d. rock salt.
b. chalk. e. siltstone.
c. chert.
20. Silicates of hydrogen and aluminum with additions of magnesium, iron and potassium are called
a. nonsilicate minerals. c. mica.
b. olivine. d. clay minerals.
Fill in the Blank
1. A naturally occurring element or compound formed by inorganic processes that has a definite chemical composition or range of compositions as well as distinctive properties that reflect its internal atomic structure is .
2. The size, shape, and arrangement of constituent minerals in a rock is called .
3. Rocks that have cooled from a molten state are .
4. Halite and the various gypsum minerals are sometimes referred to as
because they are often precipitated from bodies of water that have been subjected to intense evaporation.
5. Rocks that have been changed from previously existing rocks by the action of heat, pressure, and associated chemical activity are .
6. Orthoclase and plagioclase are members of this major group of silicate minerals called __________.
7. The minerals that are silicates of hydrogen and aluminum with additions of magnesium, iron, and potassium are called .
8. A carbonate mineral that occurs more rarely than either calcite or dolomite is .
9. A silica-rich, relatively light-colored intrusive rock composed primarily of potassium feldspar, quartz, sodium plagioclase, hornblende, and mica is .
10. The general process by which a rock subjected to high temperature and pressure is partly melted and the liquid component is moved to another location is .
Loose sediment is converted to coherent solid rock by any of several processes: precipitation of a cementing material around individual grains, compaction, or crystallization. These processes constitute .
Alterations of rock immediately adjacent to igneous intrusions constitute this type of metamorphism. .
13. The texture of a rock that is composed of grains and broken fragments (clasts) of pre-existing minerals, rocks, and fossils is called .
14. The term reserved for clastic rocks composed of fragments that are angular but similar in size to those of conglomerates is .
15. A soft, porous variety of limestone that is composed largely of extremely minute calcareous skeletal elements is called .
True/False
1. Lava is the term used to describe a mixture of molten silicates and gases while it is still beneath the surface.
2. Regional metamorphism is a type of rock alteration that is really extensive and occurs under the conditions of great confining pressures and heat accompanying deep burial and mountain building.
3. The common foliated metamorphic rocks are gneiss and marble.
4. Most metamorphic rocks exhibit a layering called foliation which results from the parallel alignment of mineral grains.
5. Slate is a nonfoliated metamorphic rock that is composed of calcite or dolomite and therefore relatively soft.
6. All sedimentary rocks are classified according to their composition and texture.
7. The most abundant limestones are of marine origin and have formed as a result of precipitation of calcite or aragonite by organisms that have died and settled to the sea floor.
8. Evaporites are chemically precipitated rocks that are formed as a result of evaporation of saline water bodies.
9. The span of time through which the earth has evolved is termed geologic time.
10. Sedimentary rocks are formed by the accumulation and consolidation of the products of weathering derived from older rock masses, as well as by chemical precipitation and the accumulation of organic debris.
Answer Key
Multiple Choice
c
c
a
a
d
b
a
d
d
a
b
b
a
a
c
d
a
b
a
d
Fill Ins
mineral
texture
igneous
evaporites
metamorphic
feldspar
clay minerals
aragonite
granite
partial melting
lithification
contact
clastic
breccia
calk
True/False
F
T
F
T
F
T
T
T
T
T
RESPONSES TO QUESTIONS ACCOMPANYING SELECTED FIGURES
FIGURE 4–13 (p. 55) Iron and magnesium are generally abundant elements in dark-colored (dark gray, black, or green) igneous rocks.
FIGURE 4–22 (p. 60) Porphyritic texture results when a magma is initially cooling very slowly so that lare crystals (phenocrysts) have ample time to grow in the melt, and then rapidly cooled (as in a volcanic eruption) so that the surrounding melt solidifies as a finely crystalline mass. As indicated in the legend, the phenocrysts are likely to be orthoclase.
FIGURE 4–25 (p. 62) According to the chart,‘midrange basalt’ would be composed of about 55 percent calcium plagioclase, 30 percent pyroxene, and 15 percent olivine.
FIGURE 4–27 (p. 64) Amphibole and biotite are likely to form when pyroxene crystals react with liquid magma. Plagioclase in granite is mostly likely to be of sodium rich variety.
FIGURE 4–33 (p. 68) Clay is the most abundant insoluble product resulting from the weathering of feldspars. Quartz is the most stable and least likely to experience dissolution during chemical weathering.
FIGURE 4–35 (p. 69) Conglomerate is composed of rounded fragments greater than 2 mm in diameter cemented in a fine-grained matrix of finer particles. In a breccia, the fragments are of the same size but are angular.
FIGURE 4–47 (p. 76) Quartzite has the same hardness as quartz and will scratch plate glass. In addition, quartzite will not effervesce on the application of dilute hydrochloric acid (as does marble).
