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41 Cards in this Set
- Front
- Back
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1. Sedimentary rocks can form
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o a. by precipitation of minerals from water solution. o b. by the cementing together of loose grains of preexisting rock. o c. from shell fragments or carbon-rich relicts of plants. o d. All the proposed answers are correct. |
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2. Choose the proper listing of detritus terms, going from smallest to largest. |
o b. mud, silt, sand
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· 3. Identify the TRUE statement: |
o a. Conglomerates consist of a single grain size. o b. Pieces of broken rock produced by physical weathering are collectively called clasts or detritus. o c. A well-sorted clastic rock is made up of different-sized particles. o d. An immature clastic rock has well-sorted, resistant grains. o e. All the possible answers are correct. |
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· 4. Which of the following features indicates the top of a sedimentary bed, or bed-surface, marker?
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o a. scour marks o b. fossil footprints o c. graded bedding o d. mud cracks o e. All the possible answers are correct. |
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5. Lithification is a general term used to describe all the physical, chemical, and biological processes that make a sedimentary rock from sediments. |
o a. True o b. False |
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6. The presence of mudcracks indicates the sediments lithified in water. |
o a. True o b. False
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· 7. A nonmarine clastic sedimentary rock composed of angular fragments surrounded by matrix is
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o a. breccia.
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· 8. Which of the following words is associated with the formation of travertine?
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o e. crystallization |
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· 9. A mud of fine calcite and/or aragonite shell debris could become which of these rocks?
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o a. micrite
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10. A clastic sedimentary rock with clay and silt-sized grains that breaks in thin sheets is called |
o b. shale.
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· 11. Which term has nothing to do with the mineral calcite?
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o a. chert o b. fossiliferous limestone o c. chalk o d. micrite o e. aragonite |
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12. An organic sedimentary rock originated as decaying plant matter is |
o b. coal.
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· 13. Identify the TRUE statement:
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o a. Both chert and limestone may have either chemical or biochemical origin. o b. Flint, jasper, agate, and petrified wood are all varieties of the siliceous rock chert. o c. Gypsum and halite are evaporite minerals. o d. Chemical sedimentary rocks are crystalline in texture. o e. All the possible answers are correct. |
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· 14. Flint and jasper were prized in early human cultures because
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o e. they broke with conchoidal fracture and thus made good cutting tools. |
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· 15. Ripple marks on a bedding plane
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o c. could suggest an ancient stream bed or a seashore.
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· 16. This diagram shown below is a profile of
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o a. ripple marks created by water flowing from A to B.
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· 17. What is the most logical past environment to have produced a deposit consisting of layers of well-sorted sandstone with cross beds several meters high?
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o b. sand dunes
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What is the most logical past environment to have produced a deposit consisting of layers of unsorted, unstratified sedimentary clasts, clay-sized to boulder-sized? |
o e. glacial valley |
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· 19. What is the most logical past environment to have produced a deposit consisting of very little sand and mud, but instead lots of broken-up carbonate shells of marine organisms?
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o c. shallow-water carbonate area
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· 20. Geologists find a thick sequence of alternating shales and sandstones. The probable depositional environment and interpretation of these are:
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o a. deep-marine deposits near the continental shelf.
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· 21. The structure that may form where a stream enters a lake
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o a. is called a delta. o b. has nearly horizontal topset beds composed of gravel. o c. has sloping foreset beds of gravel and sand. o d. has nearly horizontal silty bottomset beds on the lake floor. o e. All the possible answers are correct. |
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· 22. Which of the following geological features was NOT formed by sedimentary processes?
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o a. Columbia River Plateau, Washington o b. Bonneville Salt Flats, Utah o c. Mammoth Hot Springs, Yellowstone National Park o d. Mono Lake, California o e. Mediterranean sea floor |
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23. Which of the following sedimentary features is the surest indicator that the past environment was deep water? |
o a. turbidites
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24. Sedimentary rocks differ from igneous rocks in that sedimentary rocks can never be crystalline in texture and igneous rocks always are crystalline. |
o a. True o b. False |
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· 25. Sedimentary rocks form only at or near Earth’s surface, never at great depths.
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o a. True o b. False |
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· 26. The words weathering and erosion are synonyms; they can be used interchangeably.
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o a. True o b. False |
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27. Graywacke and conglomerate are examples of well-sorted rocks; claystone and siltstone are examples of poorly sorted rocks. |
o a. True o b. False |
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28. A rock with large, angular fragments and lots of feldspar is classified as immature; a rock with smaller, rounded grains and not much feldspar is classified as mature. |
o a. True o b. False |
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· 29. The formation of dolostone, due to the introduction of magnesium into limestone, is an example of diagenesis.
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o a. True o b. False |
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30. The word fluvial means lake. |
o a. True o b. False |
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· 31. Obvious sandstone beach deposits overlain by marine mudstone indicate transgression of the sea.
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o a. True o b. False |
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· 32. Diagenesis and metamorphism both alter the texture and mineral composition of rock; metamorphism is the higher temperature process.
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o a. True o b. False |
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· 33. A sequence of sedimentary beds, traceable across a region and distinctive enough to be recognized as a unit is called a stratigraphic formation.
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o a. True o b. False |
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· 34. Which of the following is NOT one of the major classes of sedimentary rocks?
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o a. clastic o b. biochemical o c. chemical o d. intrusive o e. organic |
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· 35. Formation of a clastic sedimentary rock involves five stages. Which of the following describes lithification?
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o b. compaction and cementation of loose particles to form solid rock
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36. As sediment is transported downstream, away from its point of origin, the particles found in the stream become |
o a. smaller. o b. rounder. o c. better sorted by size. o d. of greater resistance. o e. All the possible answers are correct. |
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37. Rocks formed dominantly from the calcium carbonate shells of marine organisms are classified as _____ and called _____. |
o c. biochemical; limestone
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· 38. Ripple marks, dunes, and cross bedding are useful indicators of
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o e. current direction. |
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39. A sedimentary basin that forms when continental lithosphere is stretched, causing down-dropped crustal blocks bordered by narrow mountain ranges and alluvial fans, is called a |
o a. rift basin.
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· 40. Sediments in a passive-margin basin are primarily fluvially derived but can also include carbonates.
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o a. True o b. False |
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· 41. When sea level rises, the shoreline migrates inland, flooding the land and depositing coastal sediments over preexisting terrestrial sediments. This process is called
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o c. transgression.
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