Physical Geology Exam II - October 2, 2006 - Prof. Kenneth A. Eriksson, Exams of Geology

Download Physical Geology Exam II - October 2, 2006 - Prof. Kenneth A. Eriksson and more Exams Geology in PDF only on Docsity! PHYSICAL GEOLOGY 1004 EXAM II — October 2, 2006 FORM A SECTION 1 CHOOSE THE BEST ANSWER AND FILL IN THE NUMBER ON THE OPSCAN SHEET. 1. Which is NOT TRUE for granitic (felsic) melts? 1. They have high silica contents 2. They have high potassium contents 3. They contain high sodium contents 4. They have high viscosities 5. They have low melting temperatures 6. All of the above are true 2. In a cooling silicate melt containing the eight most abundant elements in the crust, which mineral (s) would crystallize last? 1. olivine and Ca-plagioclase 2. biotite 3. Na-plagioclase and pyroxene 4. amphibole (e.g. hornblende) 5. quartz 3. Each Hawaiian island is made by the coalescing of volcanoes of this type. 1. shield volcano 2. cinder cone 3. composite volcano 4. Andesitic volcanoes are found 1. at converging plate boundaries. 2. at diverging plate boundaries. 3. at the mid-oceanic ridge crest. 4. at transform boundaries. 5. along fracture zones. 5. Hawaiian volcanoes have broad, gently sloping profiles because: 1. abundant tropical rainfall has smoothed then off 2. viscous rhyolitic lava has been emitted from a number of widely spaced vents 3. they have subsided into the sea somewhat 4. there has not been time to erode them into steep slopes 5. basaltic lava has a low viscosity and therefore flows easily 6. none of these of the above 6. Which of the following would be characteristic of pahoehoe lava: 1. High viscosity 2. Violent eruptions 3. Quick cooling from the surface downwards 4. Blocky surfaces 5. Felsic composition 7. A sedimentary rock that containing only quartz is a: 1. mudstone. 2. andesite. 3. basalt. 4. obsidian. 5. sandstone 8. A rock that contains no minerals is called: 1. granite. 2. andesite. 3. basalt. 4. obsidian. 5. quartz. 9. Clay minerals produced in the weathering environment are: 1. Minerals resistant to weathering 2. Iron oxides 3. New minerals consisting mainly of calcium carbonate 4. New minerals consisting mainly of aluminum, silicon and oxygen 10. Exfoliation refers to 1. trees losing their leaves due to soil deficiencies. 2. the parallel layering in metamorphic rock. 3. the tendency of some rocks to weather more rapidly than others. 4. the tendency of rocks such as granite to crack into slabs due to pressure release. 5. none of these answers is correct. 11. Intense chemical weathering results in the removal in solution of all the following cations except: 1. potassium. 2. sodium. 3. aluminum 4. magnesium 12. Acid mine drainage is common in coal mining areas and results from the reaction between: 1. Water and coal. 2. Air and coal 3. Water and Pyrite 4. Air and ash 13. Which of the following is NOT shared by gabbro and basalt: 1. Mafic composition 2. absence of quartz 3. abundant dark minerals containing Fe and Mg 4. fine-grained texture 14. The B horizon of a soil is: 1. the zone of accumulation. 2. the zone of partially disintegrating bed rock. 3. the lowest horizon of a soil. 4. the zone of leaching. 15. The following are all products of chemical weathering except: 1. pyroxene 4. kaolinite 2. silica in solution 5. Soluble cations 3. iron oxides SECTION 2 FIND THE BEST TERM TO COMPLETE THESE STATEMENTS USING THE LIST AT THE END OF THE EXAM. FILL IN THE NUMBER (1-10) ON THE OPSCAN SHEET. 31. ________ acid is be formed by CO2 dissolving in rainwater. 32. _______ solutions have a pH of less than 7. 33. The mineral that is most resistant to chemical weathering is _______. 34. _________ are small sand-sized spheres of calcite that have been directly precipitated from seawater. 35. Factors that influence weathering are rock type, slope, and _________. 36. Lithification of sedimentary rocks involves compaction and _______. 37. Weathering of feldspar produces __________. 38. The mineral halite precipitates from solution at higher salinities than _________ 39. Chemical reaction between iron and oxygen produces ____. 40. Limestones are examples of ______ sedimentary rocks. 41. Arid region soils are characterized by the accumulation of _______ in the B Horizon. 42. Chemical weathering of limestone produces ___________. 43. Turbidity currents deposit __________. 44. Organisms such as corals and clams precipitate ______ as part of their life cycle. 45. Felsic lavas are low temperature and high _________ flows. 46. Rock consisting mainly of pyroxene, olivine and Ca-feldspar is confined to the _______ crust. 47. Composite volcanos form along _______ plate boundaries. 48. Ultramafic igneous rocks make up the Earth’s _________. 49. The islands of Hawaii decrease in elevation to the northwest because of weathering and ________. 50. Tiny fragments of pyroclastic material that has been blown into the atmosphere by explosive volcanic activity is referred to as _______ . ANSWERS FOR MATCHING QUESTIONS IN SECTION B 1. Acidic 2. Ash 3. Batholith 4. Basic 5. Biochemical 6. Bombs 7. Calcite 8. Carbonic 9. Caves 10. Cementation 1. Concordant 2. Continental 3. Convergent 4. Clastic 5. Clays 6. Climate 7. Cooling 8. Crust 9. Disintegration 10. Divergent 1. Feldspar 2. Frost Wedging 3. Graded beds 4. Gypsum 5. Halite 6. Hawaii 7. Heating 8. Iceland 9. Lithosphere 10. Mantle 1. Oceanic 2. Obsidian 3. Ooids or Oolites 4. Pillows 5. Quartz 6. Rhyolite 7. Rust 8. Shield volcano 9. Sulfuric 10. Viscosity