Geology 101
Exam #3
Fall 2001

1. At current rates of use, how long will the United State's known oil reserves last?
a. less than 10 years
b. about 20-25 years
c. about 65 years
d. about 90 years
e. all of the above

2. When we take ore rock out of the ground, we separate it into ore and _________.
a. gangue
b. detritus
c. tailings
d. laterite
e. mollisol

3. Ore grade refers to
a. the concentration of ore minerals in a particular ore rock
b. the amount of reserves available to mine
c. the market value of an ore body
d. the steepness of an ore deposit
e. the size of the grains of ore minerals in a cumulate ore deposit

4. Which of the following processes may concentrate ore minerals to make an ore deposit?
a. hydrothermal waters flowing through rocks
b. gravity settling in streams, lakes or the ocean
c. gravity settling as mineral crystallize from a magma
d. by crystallization of a pegmatite
e. all of the above

5. Which of the following is not a fossil fuel?
a. coal
b. lignite
c. gas
d. uranium
e. anthracite

6. Which of the following human activities has upset the natural carbon cycle?
a. damming rivers
b. damning rivers
c. burning fossil fuels
d. mining uranium and using it in nuclear reactors
e. leaving tailings piles at mine sites

7. Which is true about oil production and use in North America.
a. we use much less than we produce
b. we use slightly less than we produce
c. we use much more than we produce
d. we use slightly more than we produce
e. we use a lot but don't produce any

8. Besides CO2, when we burn coal we put sulfur and nitrogen in the atmosphere which is bad because they turn into
a. greenhouse gases
b. smog
c. fog
d. acid rain
e. all of the above

9. Prior to 1976, over 150 commercial nuclear reactors were built in the U.S. How many have been built since then?
a. over 200
b. about 50
c. 11
d. none
e. all of the above

10. Today, most of the waste generated at nuclear power plants in the United States is
a. thrown in the ocean
b. shipped to Africa
c. shipped to Canada
d. shipped to Mexico
e. stored near where it is generated

11. Which of the following is a renewable resource?
a. human energy
b. petroleum
c. lignite
d. natural gas
e. all of the above

12. At present, most of the energy consumed in the United States comes from
a. petroleum
b. coal
c. natural gas
d. nuclear
e. hydroelectric

13. What is the main fuel for nuclear fission reactors?
a. uranium 235
b. plutonium 239
c. americium 242
d. coal
e. water

14. Name the principle ore of aluminum and describe how it forms:
a. bauxite forms by weathering
b. placer forms by gravity in water
c. cumulate forms by gravity in magma
d. gravel forms by rounding and settling
e. massive sulfide forms by filter pressing

15. Dams built to provide hydroelectricity cannot produce power forever because
a. the water eventually flows somewhere else
b. we may run out of fossil fuels
c. sediment may fill the lake behind the dam
d. concrete fractures after being exposed to the sun for long periods of time
e. environmental activists eventually blow them up

16. "Having an orderly and repetitive atomic structure"
a. igneous
b. sedimentary
c. metamorphic
d. erosion
e. crystalline

17. The nucleus of an atom contains
a. protons and electrons
b. neutrons and electrons
c. positrons and protons
d. positrons and electrons
e. protons and neutrons

18. When an atom ionizes, it
a. combines with water and oxygen to make a hydroxide
b. breaks down by nuclear reaction
c. shares electrons with another compound
d. bonds to another atom
e. gives up or gains an electron, thus getting a charge

19. Different forms of the same element having different atomic masses are called _______.
a. compounds
b. synclines
c. polymorphs
d. protons
e. isotopes

20. Which of the following is a formula of a silicate mineral?
a. Al2O3
b. CuFeS2
c. FeO
d. NaCl
e. MgSiO3

21. The term "foliation" in metamorphic rocks refers to:
a. the inclusion of fossilized plant remains in rocks
b. a quantitative measure of the degree of metamorphism
c. folding of the rock by lateral pressure
d. a consistent orientation of the mineral grains
e. the size of the lineations

22. The type of metamorphism that results entirely from the heat of magma and from hot circulating fluids is:
a. contact metamorphism
b. regional metamorphism
c. dynamothermal metamorphism
d. shock metamorphism
e. butterfly metamorphism

23. In general, gems are
a. rare minerals
b. radioactive minerals
c. beautiful varieties of common minerals
d. not colored or dyed or altered in any way from the way they occur naturally
e. made of diamond

24. Which of the following would be considered a mineral?
a. Opal.b. Diamond.
c. Obsidian.
d. Glass.
e. Dexyite

25. A silicon tetrahedron has ___ oxygen ions.
a. 1
b. 2
c. 3
d. 4
e. 5

26. The rock that results from the metamorphosis of relatively pure limestone is:
a. hornfels
b. quartzite
c. gneiss
d. marble
e. all of the above

27. In geology, a mineral is defined as:
a. a natural substance that is neither animal nor plant, has a specific composition and structure, and contains one or more silicon-oxygen tetrahedra.
b. a solid substance or element that is essential to human nutrition.
c. a naturally occurring usually inorganic solid consisting of chemical elements in specific proportions, whose atoms are arranged in a systematic internal pattern.
d. a naturally occurring crystalline inorganic solid that contains only one element.
e. anything that occurs naturally

28. What do ferromagnesian minerals have in common?
a. they are very light
b. they cleave very well
c. they form cubic crystals
d. they contain iron and magnesium
e. all of the above

29. Which of the following types of rocks can become metamorphic rocks?
a. sedimentary rocks only
b. sedimentary or igneous rocks only
c. sedimentary or metamorphic rocks only
d. sedimentary, igneous, or metamorphic rocks
e. acid rock, punk rock or grunge rock

30. Slate and phyllite resemble each other, so how might you distinguish them?
a. slate is heavier than phyllite
b. slate is lighter than phyllite
c. slate contains lots of easily seen mica crystals
d. phyllite has a sheen to it because of very small mica crystals
e. slate easily breaks into thin slabs

For each term, tell me if it refers to an igneous rock, a sedimentary rock, a metamorphic rock, an element, or to a mineral:
31. diorite
32. gabbro
33. magnesium
34. feldspar
35. sandstone
36. basalt
37. gabbro
38. mica
39. mercury
40. slate
41. shale

Short Answer Questions

42. Most high-grade metamorphic rocks and minerals form deep within the Earth. In contrast, many low-grade metamorphic rocks and minerals form at shallow levels in the Earth. Why?

43. Although all minerals have an orderly internal arrangement of atoms (crystalline structure), most mineral samples do not exhibit their crystal form. In other words, they do not have a nice pretty geometric shape. Why?

44. Define and make it clear to me that you know the difference between elements, minerals, and rocks.