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. Obsidian exhibits this texture. a. Aphanitic b. glassy c. porphyritic d. phaneritic e. pyroclastic 2. 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 3. 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 4. 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 5. Granite is the coarse-grained equivalent of this igneous rock. a. Basalt b. andesite c. rhyolite d. diorite e. granite 6. Which of the rocks listed below is a popular building stone? a. Basalt b. andesite c. granite d. diorite e. gabbro 7. 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. 8. 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. 9. 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. 10. 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. 11. Extrusive 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. 12. As the rate of cooling decreases (slows down), the size of the crystals that form a. increases b. decreases c. is not affected. 13. Which one of the following is an igneous rock? a. Limestone b. rhyolite c. slate d. shale 14. An igneous rock that contains vesicles a. is also extrusive. b. is also fine grained. c. contains many small holes d. all of these 15. Granite and rhyolite a. have a similar mineral composition. b. have a similar texture. c. a. and b. d. are in no way similar. 16. 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. 17. Which of the following is a by-product of the chemical weathering of olivine? a. Silica b. potassium and bicarbonate ions c. iron oxide d. clay e. answers a. and c. 18. The most important and/or most common mechanical weathering process is a. frost wedging b. hydrolysis c. exfoliation d. bioturbation e. thermal expansion 19. A type of chemical and/or mechanical weathering process that involves biological activity is: a. frost wedging b. hydrolysis c. exfoliation d. bioturbation e. thermal expansion 20. 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 21. 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 22. 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 23. If granite and basalt outcropped in an area with a hot and humid climate, a. the granite would weather more quickly b. the basalt would weather more quickly c. both would weather at the same rate 24. Which one of the following is NOT related to chemical weathering? In other words, which process is NOT due to chemical weathering? a. Dissolution b. frost wedging c. hydrolysis d. oxidation e. answers a., c., & d. 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. 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 2 Instructor: Terry J. Boroughs 28. Clastic sedimentary rocks are classified (named) primarily on the basis of a. Color b. particle size c. type of bedding d. mineral composition 29. Which of the following is NOT a sedimentary structure? a. Ripples b. Dunes c. Cross Bedding d. Stratification e. All of these are sedimentary structures 30. Compaction would probably be most significant as a lithification process for: a. shale b. sandstone c. conglomerate d. breccia e. answers c. and d. f. answers a. and b. 31. 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 32. The most abundant biochemical sedimentary rock is a. Limestone b. dolomite c. chert d. rock salt e. sylvite 33. 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 34. Which rock type is associated with a very low-energy environment (such as a lake or pond)? a. conglomerate b. shale c. both conglomerate and shale d. neither conglomerate nor shale 35. 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 36. 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 37. Clastic sediments would predominate (be common) in the following environments: a. Delta b. talus slope c. salt flat d. river floodplain e. answers a., b., and d. f. answers b., c., and d. 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. 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 40. 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 41. This metamorphic rock is particularly prized as a building stone a. Marble b. mica schist c. phyllite d. gneiss e. quartzite 42. The primary agent of regional metamorphism is a. Folding b. heat c. pressure or stress d. strain e. all of these Instructor: Terry J. Boroughs 3 43. 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 44. 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 45. 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 46. The agents of metamorphism are a. uplifting and folding b. foliation and deposition c. heat, pressure, and chemically active fluids d. contact and regional deformation e. slaty and platy cleavage 47. 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 48. 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 49. The common rock produced by the metamorphism of limestone is a. Marble b. mica schist c. phyllite d. gneiss e. hornfels 50. 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.