This is an example of questions from a previous midterm intended to show you the type of questions I have asked in previous years. I teach the course differently each year, so some (all?) of these question may not apply to this year. It is only intended as an example of the format of a midterm you might expect.
Multiple Choice (2 points each, total 48 points). Chose the one best answer (a-e) for each question. If you feel the question is ambiguous and therefore wish to explain your choice, mark the one answer (a-e) you feel is best and justify your choice in the space labeled F. Any ambiguities in your marking will be counted as incorrect, so make any corrections carefully and clearly.
1. Our mineral reserves are
a) the part of resources that have already been consumed
b) the entire mineral endowment of Earth
c) always smaller than mineral resources
d) usually found in igneous rocks
e) measured by satellite observations combined with lab studies
F)
2. Skewed or log-normal sample populations
a) have some very high or very low values
b) do not have the same proportions of high and low values
c) are difficult to describe accurately with an average or mean
d) all of the above
e) none of the above
F)
3. The mining law of 1872 has been widely criticized recently because
a) it allows mineral exploration in National Parks
b) it lacks provisions for payments of royalties to the government for gold and copper mining
c) it does not provide for extralateral mining rights
d) all of the above
e) none of the above
F)
4. The global sulfur cycle refers to
a) the accumulation of sulfur in the crust due to accretion of the planet
b) addition of sulfur dioxide to the atmosphere due to acid rain
c) addition of sulfur dioxide to the atmosphere due to burning coal
d) the largest amount of sulfur that can cycle through the oceans
e) the transfer of sulfur between large-scale earth reservoirs
F)
5. Earlier in its history, Earth
a) was hotter, which increased the rate of volcanism associated with seafloor spreading
b) had an oxygen rich atmosphere that permitted the formation of placer deposits containing uranium and sedimentary deposits rich in iron.
c) had large concentrations of gold in the crust, which resulted in large immiscible gold deposits
d) all of the above
e) none of the above
F)
6. Mineral deposits are called "non-renewable" because
a) environmental considerations limit the degree to which mined land can be reclaimed
b) they are formed much more slowly than the rate at which they are exploited
c) economic limitations make it impossible to mine all of the lowest grade material
d) deposits can form rapidly, but they are difficult and expensive to find
e) a and d
F)
7. Trace element
a) include elements such as O and Si, which form many rocks
b) include elements such as Al, which commonly substitute in small amounts for more abundant elements.
c) are so named because they leave traces that can be easily detected by chemical analyses allowing us to find ore deposits
d) all of the above
e) none of the above
F)
8. A natural concentration of minerals or rocks that can be mined at a profit is
a) a laterite
b) an ore deposit
c) a result of seafloor spreading
d) a placer
e) none of the above
F)
9. The safest and cheapest method for producing ore minerals from a natural deposits is
a) underground mining
b) surface mining
c) froth floatation
d) beneficiation
e) direct reduction smelting
F)
10. The windfall profits tax
a) applied only to profits obtained from sales of gold when the price exceeded $500 per ounce
b) was applied only to Oil and gas produced from federal lands
c) was an excise tax applied to the revenues from the sale of oil at prices above a specified minimum price
d) was an income tax applied to excess profits (greater than 16 2/3% of gross net production) from the sale of oil at high prices following the OPEC oil embargo
e) applied only to imported oil, but was not applied to domestic production
F)
25. Briefly define the difference between severance tax and income tax. Which tax most favors mineral conservation? Which tax provides the most stable source of income to a taxing agency? (4 points)
Examine the following chemical reactions. They are all presented in standard form with reactants on the left side of the equals sign and products on the right. Answer the following questions for each reaction, as written below. Each correct answer is worth 2 points; 2 points will be deducted for each incorrect answer.
A. ZnSO4 = Zn+2 + SO4-2
B. 2Fe+2 + 1/2O2 + 2H+ = H2O + 2Fe+3
C. SO2 + H2O + 1/2 O2 = SO4-2 + 2H+
D. CaCO3 + H+ = Ca++ + HCO3-
(Calcite)
E. 2FeS2 + 2H2O + 7O2 = 4H+ + 4SO4-2 + 2Fe+2
(pyrite)
F. CO2 + H2O = H+ + HCO3-
G. NaCl = Na+ + Cl-
H. 2KAlSi3O8 + 2H+ + H2O = 2K+ + Al2Si2O5(OH)4 + 4 SiO2
(Potassium feldspar) (Kaolinite)
26. Which reaction(s) are acid producing? ______________________________
27. Which reaction(s) consume acid? ______________________________
29. Which reaction is the most important source of anthropogenic acid rain? ____
30. The moon is made predominantly of basaltic rocks. Plate tectonics does not operate on the moon because the interior is solid. There is no free flowing water on the moon and the moon never had a significant atmosphere. Give three examples of mineral deposits, each formed by a different geological process, that you would not expect to find on the moon. Give one example of a mineral deposit type you might expect to find on the moon. In each case, provide a short justification for your answer; no justification, no points. (8 points)
31. Provide a coherent discussion (well organized, clearly stated, complete sentences) of mercury (Hg) in the environment. Your discussion should include, but not necessarily be limited to, the natural and human influenced sources of Hg, the distribution of Hg in the environment, and the geochemical and biological controls on distribution and environmental consequences of Hg. (20 points).