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GE2100 Environmental Geology - Exam 2 (Spring 2005)
Each question is worth 2 pts - show your work to get credit for calculations!
TRUE OR FALSE
1. If the rate of groundwater withdrawal exceeds the rate of recharge, regional water tables may be lowered.
2. Artesian water is desirable for making beer because it is unusually pure and clean.
3. The “water table” is the top of the saturated zone in the subsurface.
4. The link between plate tectonics and formation of mineral deposits has made the search for new ores more efficient.
5. In the United States, we use many times greater amounts of rock resources, like sand and gravel, than we do of metals like iron and copper.
6. To promote national security, the U.S. Strategic Petroleum Reserve is increased as necessary to maintain a one-year supply of oil.
7. Exploration techniques are now so efficient that approximately one out of every two exploratory wells drilled strikes a commercially valuable deposit of oil or natural gas.
8. As sediments rich in marine microorganisms undergo deeper burial, the organic molecules are broken down into simpler and simpler hydrocarbons, progressing from heavy oils to natural gas.
9. The seriousness of many environmental problems is a direct result of the large number of humans interacting with the environment.
10. Population growth rates are very nonuniform worldwide, with the fastest rates of increase in the technologically advanced countries.
11. The Woburn, MA environmental problems concerned
a) the effects of acid mine drainage on a nearby housing development
b) ground subsidence from excess groundwater removal
c) city well water contaminated by industrial waste
d) a disastrous oil spill near Boston, MA
12. The Earth’s current population is 6 billion, with an annual growth rate of 1.3 percent. Assume exponential growth (equation: N = No * ekt). How long will it take for the population to double?
13. As population increases,
a) the demand for resources will tend to increase.
b) growing demand for resources will ensure that more will always be found.
c) natural systems will continue to compensate adequately for such disruptions as pollution; the earth is a big place.
d) all of the above.
14. The Earth’s carrying capacity is:
a. defined as the ability to sustain the population at a basic healthy lifestyle.
b. calculated primarily as a function of population versus land surface area.
c. consistently predicted to be at 30 billion people.
d. independent of agricultural efficiency.
15. At the current daily use of 20 mbo, the U.S. reserves of 25 bboare sufficient to meet about _____ years of domestic demand. Remember, according to Dr. Wylie, about 50% of the U.S. daily usage is imported.
a. 2
b. 7
c. 50
d. zero; the United States has no significant oil reserves.
16. The world’s petroleum reserves are approximately:
a. 2 million barrels
b. 200 billion barrels
c. 2 trillion barrels
d. 200 trillion barrels
17. The number of gallons in a barrel of oil is:
18. Which of the following statements is not true?
a. oil was first extracted for commercial uses in Pennsylvania, in 1859
b. Texas was the main oil producing region in the early 1900’s
c. Middle East oil reserves became dominant in the 1950’s
d. Geophysical methods for oil exploration began in the 1980’s
19. Gas prices reflect
a) price of crude oil
b) refining and transportation costs
c) Federal and state taxes
d) all of the above
20. Coal is formed from
a) the remains of land plants.
b) graphite under high pressure.
c) the remains of marine microorganisms.
d) heavy oils like asphalt.
21. Which of the following is estimated to be the largest potential fuel resource?
a) oil
b) conventional natural gas
c) gas in gas hydrates
d) coal
22. Enhanced oil recovery methods include
a) deliberate fracturing to increase reservoir porosity
b) use of gas under pressure to force out more oil.
c) heating the oil to decrease its viscosity.
d) all of the above.
23. Most oil and natural gas is found in
a) igneous rocks
b) metamorphic rocks
c) sedimentary rocks
d) volcanic rocks
24. In a petroleum trap,
a) either oil or gas will be found, but not both.
b) the oil is found dissolved in pore water under pressure.
c) the oil and gas are found in impermeable rocks.
d) gas and oil may both be found, contained by impermeable rocks above.
25. Most of the water consumed in the United States is consumed by
a) agriculture
b) thermoelectric power generation
c) municipal water supply systems
d) hydroelectric power generation
26. Recharge of aquifers may be reduced by all of the following except
a) consumption of artesian well water.
b) the filling-in of a swamp for construction.
c) construction over the recharge area of a confined aquifer.
d) increasing the efficiency of surface runoff.
27. Possible consequences of excessive groundwater withdrawal include
a) surface subsidence
b) swelling of aquifer rocks
c) increased permeability of aquifer rocks
d) all of the above
28. Around an actively pumped well in an unconfined aquifer, a _____ may develop in the water table.
a) sinkhole
b) recharge
c) cone of depression
d) zone of saturation
29. The largest reservoir of unfrozen fresh water is
a) the water in all lakes and streams.
b) ground water.
c) water in the atmosphere.
d) water in the biosphere.
30. Hard water is
a) water containing high levels of dissolved calcium and magnesium.
b) hard to drink because it tastes bad.
c) hard to extract from aquifers because of all the dissolved minerals.
d) all of the above.
31. Which of the following would probably have the highest porosity?
a) sandstone
b) rock salt
c) granite
d) gneiss
32. The ease with which fluids pass through a rock is determined by the rock’s
a) porosity.
b) permeability.
c) grain size.
d) age.
33. Select the one statement which does not accurately describe the "water table":
a. is the boundary between the saturated and unsaturated zones.
b. generally follows topography in its depth from the surface.
c. remains constant throughout the year.
d. intersects the surface at lakes, rivers, and wetlands.
34. Assuming that all of the following rocks are unfractured and unweathered, which would likely make the best aquifer?
a. gneiss
b. basalt
c. shale
d. sandstone
35. Why (explain your answer above, using proper terminology)?
36. The EPA's Primary and Secondary Drinking Water Standards focus on, respectively:
a. taste, and smell charactieristics
b. health, and aesthetic concerns
c. copper, and iron concentrations
d. organic, and inorganic contaminants
37. Water resource engineers estimate that every person requires 100 gallons (gallon = 3.8 L) of water per day. If Hancock (population = 7,000) decided to fluoridate their water at 1.5 ppm (= mg/L), how much fluoride (in kilograms) would have to be added to their daily water supply?
38. If demand forces metal prices up, all of the following can be expected except
a) development of lower-grade ore deposits.
b) significant rapid increases in total world metal resources.
c) disturbance of more land area for mineral extraction.
d) reclassification of some resources as reserves.
39. All of the following are mined from evaporite deposits except
a) halite.
b) gypsum.
c) phosphates.
d) quartz.
40. Which of the following was NOT discussed by Dr. Mayer as a potential environmental impact of the Yellowdog Mine, which has been proposed in the nearby Huron Mountains?
a) disposal of waste rock and other material processing
b) extraction of water from the mine (dewatering the mine shaft)
c) strip mining causes changes in topography and hydrology
d) dewatering can change the path of groundwater flow in the area
41. Jeremy Shannon discussed potential Yellowdog Mine acid drainage – which factor is least important?
a) sulfide ores
b) silicate ores
c) oxygen-rich environment
d) water
42. Weathering in tropical climates can produce residual ores rich in
a) calcite and quartz.
b) feldspar and mica.
c) sulfur and sulfide ores.
d) iron and aluminum.
43. An igneous rock from which diamonds may be mined is
a) pegmatite.
b) evaporite.
c) kimberlite.
d) iron formation.
44. Ore deposits of dense minerals concentrated by stream action are
a) evaporates.
b) placers.
c) hydrothermal.
d) metamorphic.
45. Hydrothermal ore deposits
a) are formed by deposition of dissolved minerals from hot fluids.
b) are found only at seafloor spreading ridges.
c) produce only a few kinds of valuable ores, mostly of precious metals.
d) all of the above.
46. Dense minerals, like chromite and native gold, may be concentrated in a crystallizing magma chamber by
a) fluids.
b) gravity.
c) gases.
d) porosity.
47. An igneous rock with very large crystals, often enriched in rarer elements, is
a) pegmatite.
b) placer.
c) kimberlite.
d) chromite.
Choose any three rock samples. Identify what type of ore deposit it represents, and explain your reasoning.
Sample # / Ore Deposit Type / Reasoning48.
49.
50.