Geology 101, Exam 4, 2000

 

  1. What kind of contact is between granite and basalt in the Moscow-Lewiston region? A) an intrusive contact; B) a metamorphic contact; C) a normal fault; D) a thrust fault; E) none of the preceding.
  2. What is believed to be the tectonic origin of the Snake River Plain ? A) a plate boundary; B) a hotspot track; C) an ancient subduction zone; D) a thrust fault; E) a monocline.
  3. What are the giant gravel bars in the Snake River due to? A) deposition by glaciers; B) formation by meandering streams; C) a giant flood; D) the building of dams by giant beavers; E) slow and steady deposition.
  4. On our field trip, we saw 3 major geologic formations: basalt, granite/gneiss, and loess. What was their order of formation, from oldest to youngest? A) basalt, granite, loess; B) granite, loess, basalt; C) granite, basalt, loess; D) loess, basalt, granite; E) loess, granite, basalt.
  5. Before the first star formed, what elements formed the universe? A) iron and silicon; B) silicon and oxygen; C) iron and oxygen; D) hydrogen and helium; E) hydrogen and iridium.
  6. Silicates are the most important mineral group. Their common feature is linked ________ of silicon and oxygen: A) octahedra; B) boxes; C) rings; D) tetrahedra; E) channels.
  7. The earth has been determined to be 4,650,000,000 years old on the basis of radioactive age determinations of what type of rock? A) gneisses; B) schists; C) marbles; D) all of the preceding; E) none of the preceding.
  8. A large amount of evidence exists suggesting that a 10 km diameter meteorite hit the earth at the end of the _______ era: A) Precambrian; B) Paleozoic; C) Pleistocene; D) Mesozoic; E) Cenozoic.
  9. With increasing amounts of stress, rocks progressively go through _____, _____, and _______ types of strain: A) elastic, plastic, brittle; B) yield, elastic, brittle; C) brittle, plastic, elastic; D) elastic, brittle, plastic; E) plastic, yield, elastic.
  10. Magnetic stripes occur parallel to what feature? A) hotspots; B) mid-ocean ridges; C) subduction zones; D) transform faults; E) the equator.
  11. What is an example of a mountain range formed by continental collision? A) the Himalayas; B) the Cascades; C) the Rockies; D) the Basin and Range; E) the Andes.
  12. What causes Milankovitch cycles? A) the tides; B) changes in the orbit and rotation of the earth; C) changes in sunspot activity; D) the moon; E) oxygen isotopes.
  13. What is the main reason the surface of Venus is nearly 500o hotter than the surface of Earth? A) Venus is much closer to the sun; B) Venus's atmosphere is much richer in carbon dioxide; C) Venus is much more reflective; D) the earth has glaciers; E) Milankovitch cycles.
  14. If you had to find a reservoir of oil, what type of geologic feature would you look for? A) Ice age till; B) a shield volcano; C) flood basalts; D) Cenozoic schists; E) a Paleozoic unconformity.
  15. The promised "diagram question". Which of the following best represents a cross section view of the structure on the Lewiston grade (the lines represent rock layers; dashed lines are faults)? C

    16.  

  16. The discovery that there have been many glacial-interglacial cycles in the past 1,600,000 years was based on: A) iridium distribution in glacial sediments; B) iridium distribution in fossil plankton; C) oxygen isotope ratios in meteorites; D) oxygen isotope ratios in fossil plankton; E) none of the preceding.
  17. Ores of metals like copper, lead, and zinc come from the ______ minerals: A) silicate; B) sulfide; C) carbonate; D) oxide; E) sulfate.
  18. Which of the following has not been used to support the theory of plate tectonics? A) similar fossils in rocks older than 200 million years in Africa and North America; B) widely different life forms in eastern and western Indonesia; C) the worldwide distribution of transform faults; D) the concentration of meteorites in Antarctica; E) actual measurements of motion using satellite technology.
  19. At what type of plate boundary would you be most likely to find a normal fault? A) mid-ocean ridge; B) transform; C) island arc; D) continental arc; E) continental collision zone.
  20. What part of the earth is made out of liquid metal? A) the hydrosphere; B) the mantle; C) the lithosphere; D) the outer core; E) the asthenosphere.
  21. About how many magnitude 4 earthquakes does it take to release the same amount of energy as a magnitude 5 earthquake? A) 1; B) 5; C) 10; D) 30; E) 100.
  22. If an earthquake has an epicenter in Boise, which wave will arrive in Moscow first? A) S; B) surface; C) P; D) tsunami; E) they will arrive at the same time.
  23. What is the main ingredient in magma that causes it to explode? A) water; B) silicon; C) nitrogen; D) quartz; E) feldspar.
  24. Where does the white volcanic ash in the Snake River canyon near Lewiston come from? A) Mt. Rainier; B) Yellowstone; C) Mt. Hood; D) Columbia River basalts; E) Mt. Mazama (Crater Lake).
  25. What type of lava makes up the Columbia River basalt flows? A) pahoehoe; B) aa; C) pillow lavas; D) all of the preceding; E) A and B only.
  26. Which of the following rocks has finer grains than a sandstone? A) conglomerate; B) breccia; C) shale; D) all of the preceding; E) none of the preceding.
  27. If a schist undergoes more severe metamorphism, what will it turn into? A) slate; B) basalt; C) peridotite; D) gneiss; E) marble.
  28. What group of meteorites has undergone the least amount of differentiation since the formation of the solar system? A) granites; B) chondrites; C) achondrites; D) rhyolites; E) irons.
  29. How does CO2 cause the Greenhouse effect? A) by absorbing incoming solar radiation; B) by absorbing outgoing infrared radiation; C) by reflecting solar radiation; D) by increasing the amount of carbon-14; E) by absorbing other radioactive isotopes.
  30. What is the main cause of the El Nino climate event? A) large changes in ocean currents in the north Atlantic; B) abnormally warm water in the equatorial Pacific; C) upwelling of deep water in the south Pacific; D) all of the preceding; E) none of the preceding. Note: this question was a bit vague with respect to cause and effect, so I accepted either B or E.
  31. If a stream has a discharge of 1000 gallons/second during a 30-year flood, what is a possible discharge for a 100-year flood? A) 100 gallons/second; B) 500 gallons/second; C) 33.3 gallons/second; D) 1000 gallons/second; E) 2000 gallons/second.
  32. What feature listed below is NOT caused by glacial erosion or deposition? A) moraine; B) U-shaped valley; C) flood plain; D) cirque; E) horn.
  33. What is thought to have been the cause of the buildup of glacial lake Missoula, the source of the Spokane flood? A) giant ripple marks; B) a dam formed by glacial ice; C) a dam formed by a moraine; D) a giant gravel bar; E) a giant waterfall.
  34. The water table separates the zone of aeration from the ________: A) vadose zone; B) zone of recharge; C) zone of discharge; D) contaminant plume; E) saturated zone.
  35. What is the main reason that subduction zones make magma? A) by introducing hot lithosphere into the asthenosphere; B) by cooling off the lithosphere; C) by introducing water to the asthenosphere; D) by converting eclogite to basalt; E) by the plate deflecting off the outer core.
  36. Why would you become a famous scientist if you discovered a dinosaur fossil in Paleozoic shales in central Idaho? A) there were no dinosaurs in what is now Idaho; B) shale is a metamorphic rock and fossils are only found in igneous rocks; C) dinosaurs did not inhabit the earth until the Mesozoic; D) there are no Paleozoic rocks in Idaho; E) dinosaurs were abundant during the Precambrian but went extinct in the Paleozoic.
  37. In addition to a source rock and reservoir rock, what is the main geologic feature that is required to form an economic oil deposit? A) a dike; B) a sill; C) a syncline; D) a structural trap; E) loess.
  38. Most ores form by deposition of metals from what? A) rhyolite magma; B) hydrothermal waters; C) seawater; D) freshwater lakes; E) eclogite.
  39. Milankovitch cycles are caused by changes in: the tilt of the spin axis, the wobble of the spin axis, and the ________: A) crystallization of the inner core; B) length of the day; C) length of the year; D) shape of the earth's orbit; E) tidal bulge.

40. What causes inflation pits in lava flows? A) meteorite impacts; B) lava flowing around large dinosaurs; C) airplanes crashing into thick lava flows; D) large phenocrysts; E) two lobes of a lava flow inflating together.

 

 

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