DATE DUE: Name: Instructor: Ms. Terry J. Boroughs Geology 305 INTRODUCTION TO ROCKS AND THE ROCK CYCLE Instructions: Read each question carefully before selecting the BEST answer Provide specific and detailed answers to essay questions. Use GEOLOGIC VOCABULARY where APPLICABLE! 1. Granite and gabbro a. have a similar mineral composition. b. have a similar texture. c. a. and b. d. are in no way similar. 2. Andesite exhibits this texture. a. Aphanitic b. glassy c. porphyritic d. phaneritic e. pyroclastic 3. The composition of an igneous rock a. is controlled by the composition of magma. b. is the shape of the rock body. c. determines the color of the rock. d. records the rock's cooling history. e. Answers a. and c. f. Answers a. and b. 4. The texture of an igneous rock a. is controlled by the composition of magma. b. is the shape of the rock body. c. determines the color of the rock. d. records the rock's cooling history. e. Answers a. and c. f. Answers a. and b. 5. Igneous extrusive rock is formed a. on the surface of the Earth b. at great depth within Earth c. by crystallization of molten rock d. answers a. and c. e. answers b. and c. 6. Igneous intrusive rock is formed a. on the surface of the Earth b. at great depth within Earth c. by crystallization of molten rock d. answers a. and c. e. answers b. and c. 7. Intrusive rocks: a. are generally coarse grained b. form below the Earth's surface c. are quite often vesicular d. are also termed volcanic e. answers c. and d. f. answers a. and b. 8. As the rate of cooling increases (speeds up), the size of the crystals that form a. increases b. decreases c. is not affected. 9. Which one of the following is an igneous rock? a. Limestone b. rhyolite c. slate d. shale 10. An igneous rock that contains vesicles a. is also extrusive. b. is also fine grained. c. contains many small holes d. all of these
11. Select the coarse grained rock, which is composed mainly of quartz and potassium feldspar from the list below: a. Basalt b. andesite c. rhyolite d. granite e. diorite 12. Rocks that contain large crystals that are roughly equal in size and can be identified without a microscope are said to exhibit this texture: a. Aphanitic (fine grained) c. glassy e. porphyritic b. Phaneritic (coarse grained) d. pyroclastic 13. This igneous texture is characterized by two distinctively different crystal sizes. a. Aphanitic (fine grained) c. glassy e. porphyritic b. Phaneritic (coarse grained) d. pyroclastic 14. Diorite is the coarse-grained equivalent of this igneous rock. a. Basalt b. andesite c. rhyolite d. diorite e. granite 15. Which of the rocks listed below is a popular building stone? a. Basalt b. andesite c. granite d. diorite e. gabbro 16. Which of these factors influence the type and rate of weathering in general? a. mineral content c. climate e. presence of cracks b. topography d. all of these 17. Chemical weathering would be most effective: a. in a warm, dry climate b. in a cold, dry climate c. in a hot, humid climate d. equally in any kind of climate 18. Which one of the following is true about mechanical weathering? a. produces smaller pieces b. adds to the effectiveness of chemical weathering c. may lead to the formation of talus slopes d. can change the rock's appearance e. all of these are true of mechanical and/or physical weathering 19. If granite and basalt outcropped in an area with a hot and humid climate, a. the granite would weather more rapidly b. the basalt would weather more rapidly c. both would weather at the same rate 20. Which one of the following is related to chemical weathering? In other words, which process is due to chemical weathering? a. Dissolution b. frost wedging c. hydrolysis d. oxidation e. answers a., c., & d. 21. Which of the following is a by-product of the chemical weathering of potassium feldspar? a. Silica b. potassium and bicarbonate ions c. iron oxide d. clay e. answers a., b. & d. 22. Which of the following is a by-product of the chemical weathering of pyroxene? a. Silica b. potassium and bicarbonate ions c. iron oxide d. clay e. answers a. and c. 23. Calcite and Halite will chemically weather in the following way: a. Dissolution b. frost wedging c. hydrolysis d. oxidation e. answers a., c., & d. 24. The most important and/or most common mechanical weathering process is a. frost wedging b. hydrolysis c. exfoliation d. bioturbation e. thermal expansion 25. Soils contain the following: a. Humus (organic material) c. Water d. Air e. All of these b. Regolith (solid material such as rock and mineral fragments) 26. Soils differ from Sedimentary deposits in the following way: a. Soils contain organic material, sediments do not b. Soils can sustain plant life, sediments do not c. Soils contain regolith, sediments do not 27. Sedimentary rocks a. may contain fossils b. hold important clues to Earth's history c. are layered d. may be economically important e. all of these 28. The most abundant biochemical sedimentary rock is a. Limestone b. dolomite c. chert d. rock salt e. sylvite 2 Instructor: Terry J. Boroughs
29. Non-clastic (Chemical or Biological) sedimentary rocks are classified (named) primarily on the basis of a. Color b. particle size c. type of bedding d. mineral composition 30. Clastic sediments would predominate (be common) in the following environments except for a: a. Delta b. talus slope c. salt flat d. river floodplain e. all of these 31. One of the most abundant inorganic chemical sedimentary rock that can only be formed by inorganic means is: a. Limestone b. dolomite c. chert d. rock salt e. sylvite 32. Which rock type is associated with a very high-energy environment (such as a large high velocity river)? a. conglomerate b. shale c. both conglomerate and shale d. neither conglomerate nor shale 33. Which pair of minerals is most common in detrital (clastic) sedimentary rocks? a. quartz and olivine b. calcite and clay c. halite and feldspar d. clay minerals and quartz e. dolomite and gypsum 34. Which of the following is a sedimentary structure? a. Ripples b. Dunes c. Cross Bedding d. Stratification e. All of these are sedimentary structures 35. Compaction would probably be least significant as a lithification process for: a. shale b. sandstone c. conglomerate d. breccia e. answers c. and d. f. answers a. and b. 36. Which of the following lists presents forms of coal in the correct order from lowest grade to highest grade? In other words, from larger amounts of impurities to smaller amounts of impurities; i.e. (impure varieties to more pure varieties.) a. lignite, bituminous, anthracite b. bituminous, anthracite, lignite c. anthracite, lignite, bituminous d. lignite, anthracite, bituminous e. anthracite, bituminous, lignite 37. Clastic sedimentary rocks are classified (named) primarily on the basis of a. Color b. particle size c. type of bedding d. mineral composition 38. Metamorphism may result from: a. heat b. pressure c. chemically active fluids d. any or all of these e. only heat and pressure 39. Through metamorphic activity a. granite can change to gneiss b. limestone can change to marble c. quartz sandstone can change to quartzite d. answers a., b., and. c. e. answers f. and g. f. granite can change to clay minerals g. slate can change to shale 40. When certain minerals re-crystallize with a preferred orientation due to directed pressures, such as crystals that form perpendicular to the direction of the compressional force, the rock exhibits: a. Shear b. foliation c. aureole d. all of these e. none of these Instructor: Terry J. Boroughs 3
41. Many metamorphic rocks a. are extremely fossiliferous (contains fossils) b. have a linear orientation of minerals c. are unaltered sedimentary rocks d. all of these e. none of these 42. The common rock produced by the metamorphism of limestone is a. Marble b. mica schist c. phyllite d. gneiss e. hornfels 43. Which of the following changes may occur during metamorphism? a. crystals may grow larger b. certain minerals may recrystallize c. the rock becomes more compact d. all of these e. answers a. and b. 44. What type of metamorphic rock will shale normally become following high-grade metamorphism? a. marble b. mica schist c. slate d. gneiss e. none of these 45. The agents of metamorphism are a. uplifting and folding b. foliation and deposition c. heat, pressure, and chemical fluids d. contact and regional deformation e. slaty and platy cleavage 46. Most of the heat for contact metamorphism is supplied by a. frictional heating along a fault b. a nearby mass of magma c. radioactive elements d. deep burial within Earth e. heat trapped by cap rock 47. This metamorphic rock is composed of alternating bands of light and dark silicate minerals a. Marble b. mica schist c. phyllite d. gneiss e. quartzite 48. This hard, dense, non-foliated metamorphic rock is produced most often from deformation of sandstone or chert. a. Marble b. mica schist c. phyllite d. gneiss e. quartzite 49. This metamorphic rock is particularly prized as a building stone a. Marble b. mica schist c. phyllite d. gneiss e. quartzite 50. The primary agent of regional metamorphism is a. Folding b. heat c. pressure or stress d. strain e. all of these 51. The process of metamorphism involves a. formation of rock from magma b. transformation or deformationof pre-existing rock c. weathering and/or decomposition of pre-existing rock d. mass movement of rock material e. only Precambrian rocks True = A/False = B 52. Bowen's reaction series helps to explain different igneous rock compositions. 53. Olivine and quartz are NOT commonly found together in the same rock. 54. The coarse-grained equivalent of Basalt is Diorite. 55. A single magma can evolve (undergo magmatic differentiation) to produce several different igneous rocks having different mineral compositions. 56. Feldspars can easily weather to form Kaolinite clay. 57. Clay minerals, such as Kaolinite, are a product of chemical weathering. 58. Some sedimentary deposits can sustain plant life. 59. Chemical weathering is slowest in a hot, humid setting. 60. Soils can NOT sustain plant life. 4 Instructor: Terry J. Boroughs
61. Texture and grain size is the primary basis for distinguishing among the various clastic, detrital sedimentary rocks. 62. Texture and grain size is the primary basis for distinguishing among various chemical sedimentary rocks. 63. The single most characteristic feature of sedimentary rocks horizontal stratification, or horizontal beds that are deposited as sediments blanket an area. 64. The most abundant sedimentary rock is shale, which covers much of the ocean s floor. 65. Most limestone has a inorganic chemical origin. 66. Metamorphism is commonly associated with mountain building. 67. Metamorphism can affect any rock type, even other metamorphic rocks. 68. When sandstone contains appreciable quantities of plagioclase feldspar, the rock is called arkose sandstone. 69. Foliation is caused by directed pressures. 70. The largest quantity of metamorphic rock is produced by regional metamorphism. Fill-in and Essay Questions: 71. Igneous rocks are classified on the basis of their mineral composition and. 72. Basalt exhibits a texture. 73. Granite is an igneous rock because it forms from the crystallization of magma below the surface. 74. Rock salt will undergo a type of chemical weathering in which the solid material is returned to its original ionic state. 75. is a form of chemical weathering which occurs when feldspar minerals incorporate water to form clays, ions and/or other compounds. 76. is a type of chemical weathering that primarily affects iron bearing silicates and other iron-rich rocks. 77. often form due to the large scale dissolution of the calcite in limestone or marble rocks over time. 78. A type of physical or mechanical weathering that involves plants or animals is called: 79. A type of physical or mechanical weathering that involves the weathering of various layers of sedimentary rock that weather at different rates due to their various composition and/or hardness which in turn, produces a terraced appearance is called: 80. A type of physical or mechanical weathering that involves the rounding of a particle either in-situ (in place) or by the tumbling action of a river is called: 81. When water in cracks and joints freezes and expands the rock is broken into angular fragments. This process is known as. 82. Another term for the organic material present in soils is called: 83. When intrusive igneous rock is exposed to the surface, it can produce a form of weathering that exhibits sheet-like structures and the process itself is called: 84. When a sedimentary rock consists of rounded, gravel-sized particles, it is called. 85. A common sedimentary structure that occurs in fine grained rocks due to intermittent presence of water, is: 86. Sandstones that contain abundant potassium feldspar that has not been transported very far from its source is called an: sandstone. 87. Rock salt and rock gypsum are common examples of a group of chemical sedimentary rocks that form through the process of: (hint: think about how they form or what process they are associated with!) 88. A common sedimentary structure that occurs in sedimentary rocks and is often found on the top of a migrating sand dune due to the oscillating movement of wind or water currents is called: 89. Metamorphism that occurs at the ocean floor due to alteration of rocks by chemically active fluids near mid-ocean ridges is called: metamorphism 90. Metamorphism that occurs at depth due to intense confining pressures associated with the weight of the overlying rocks and/or sediments is called metamorphism. 91. Metamorphism that occurs at depth due to intense directed pressures along plate boundaries and produces extensive foliation is called metamorphism. 92. Metamorphism that occurs due to the intense shearing along faults is called: metamorphism. 93. Metamorphism that occurs because of close proximity to a mass of magma is called metamorphism. Instructor: Terry J. Boroughs 5
94. When a metamorphic rock is uniform in appearance without any layering, it is said to exhibit a texture. 95. When a metamorphic rock exhibits a layered or banded appearance, it is said to exhibit a texture. 96. Metamorphic rocks often contain large crystals called porphyroblasts that grow preferentially during metamorphism and are indicative of the temperature and pressure conditions. These minerals are referred to as minerals because they indicate the metamorphic conditions. 97. List three different types of chemical weathering.,, 98. List three different agents of metamorphism.,, GEOLOGY 305: INTRODUCTION TO ROCKS-CLUES ACROSS 1. This term describes minerals that are high in silica. 7. This term describes an object composed of one or more minerals. 9. A term used to describe rock that is molten. 10. These types of rock are produced by the solidification of magma. 11. This type of weathering involves the breakdown of minerals at the atomic level. 15. These deformed rocks are produced by an increase in temperature, pressure, and/or chemically active fluids. 21. A term used to describe igneous rocks that form in the subsurface. 23. This type of sedimentary rocks is composed of detrital sediments. 25. A common igneous intrusive rock that is felsic and phaneritic. 26. A common extrusive rock that is aphanitic and mafic. DOWN 2. This term describes minerals that contain high amounts of iron and magnesium and very little silica. 3. The describes the recycling of the three rock groups that make up the Earth s crust. 4. The deformation of a pre-existing rock, which is caused by an increase in temperature, pressure, and/or chemically active fluids. 5. These rocks are produced by the process of diagenesis of sediments. 6. This general term describes igneous rocks that are rich in nonferromagnesian minerals. 8. A deposit of fine-grained pyroclastic material. 12. The process by which rocks and minerals are broken down. This process is often associated with the process of erosion. 13. The parallel alignment of minerals, etc. due to the directed pressures associated with metamorphism. 14. All rocks are classified based upon two general criteria. Texture is one and is the other. 16. A general term used to describe intrusive rocks and the solidified bodies they produce. 17. A type of physical/mechanical weathering that involves the unloading and expansion of intrusive rocks. 18. A general term to describe igneous rocks that are rich in ferromagnesian minerals. 19. These types of igneous rocks form on the surface of the Earth and are often associated with volcanic processes. 20. Classification of rocks is based upon and mineral content. 22. A common non-foliated metamorphic rock. 24. Molten magma that is erupted onto the surface. GEOLOGY 305: INTRODUCTION TO ROCKS - WORD LIST ASH GABBRO METAMORPHISM BASALT GRANITE MINERALOGY CHEMICAL IGNEOUS NONFERROMAGNESIAN CLASTIC INTRUSIVE PLUTONIC EXFOLIATION LAVA ROCK EXTRUSIVE MAFIC ROCK CYCLE FELSIC MAGMA SEDIMENTARY FERROMAGNESIAN MARBLE TEXTURE FOLIATION METAMORPHIC WEATHERING 6 Instructor: Terry J. Boroughs