1. Erupted lavas are predominantly fine-grained because

A. there is very little water in the extruded magma.

B. they are made up of minerals which never form large crystals.

C. rapid cooling allows for insufficient time for large crystals to grow.

D. the lava crystallizes under very low pressure conditions.

2. Coarse-grained igneous rocks, like granite, are exposed on the Earth's surface today because

A. of uplift and erosion.

B. quickly cooled lavas erupted from ancient volcanoes.

C. silicate minerals precipitated from rainwater.

D. all of the above.

3. A porphyritic texture is formed

A. by a period of rapid cooling followed by a period of slow cooling.

B. by a period of slow cooling followed by a period of rapid cooling.

C. by the very slow cooling of a water-rich magma.

D. when a magma first crystallizes mafic minerals and then felsic minerals.

4. Sedimentary rocks are formed from loose sediments by

A. compaction and cementation.

B. erosion and deposition.

C. wind and water.

D. metamorphism.

5. Which of the following is a carbonate sedimentary rock?

A. Slate.

B. Basalt.

C. Conglomerate.

D. Limestone.

E. Shale.

6. The most abundant sediment in the Earth's crust is

A. shale.

B. sandstone.

C. basalt.

D. limestone.

7. A material that would not make a good cement for binding rock particles together to form a sedimentary rock is

A. clay.

B. calcium carbonate.

C. silica.

D. sand.

8. What is the distinguishing characteristic used to define the terms gravel, sand, silt, and clay?

A. Particle mineralogy.

B. Particle shape.

C. Sediment location.

D. Amount of fossils.

E. Particle size.

9. Which sequence of rock names is correctly arranged in order of decreasing particle diameters?

A. Conglomerate, shale, sandstone.

B. Sedimentary breccia, shale, sandstone, claystone.

C. Conglomerate, sandstone, claystone.

D. Shale, siltstone, sandstone.

10. What distinguishes conglomerate from breccia?

A. Grain size.

B. Grain composition.

C. Amount of matrix present.

D. Composition of cement.

E. Grain shape.

11. The sand grains in sandstone may be composed of

A. quartz.

B. mica.

C. rock fragments.

D. feldspar.

E. all of the preceding.

12. Not all sands are made of quartz grains. The sands of White Sands National Monument are made of

A. calcite.

B. gypsum.

C. broken fossil fragments.

D. basalt fragments.

13. What is the dominant mineral in a limestone?

A. Quartz.

B. Calcite.

C. Dolomite.

D. Feldspar.

E. Rock fragments.

14. Limestone overlain by shale overlain by sandstone tells you that

A. sea level was falling.

B. mountains were rising.

C. mountains were being eroded down.

15. Which has a crystalline texture?

A. Shale.

B. Arkose.

C. Quartz sandstone.

D. Rock salt.

E. Oolitic limestone.

16. In which of the following environments would you expect abundant carbonate sediments to be deposited?

A. Arctic Ocean.

B. Florida Keys.

C. Coast of Alaska.

D. Mississippi River channel.

17. In which of the following environments would you expect calcium carbonate to dissolve rather than to precipitate?

A. The Arctic Ocean.

B. The Great Salt Lake, Utah.

C. Soil in southern Arizona.

D. Yellowstone hot springs, Wyoming.

18. A sequence of coarse sandstones and conglomerates that contains coarse cross-beds and channel deposits probably was deposited in

A. a delta.

B. a flood plain.

C. a beach.

D. a lagoon.

E. an alluvial fan.

19. A sequence of siltstone and shale layers contains numerous mud cracks and ripple marks. What environment of deposition is most likely for these rocks?

A. Fast-moving stream.

B. Tidal flat.

C. Deep marine.

D. Beach with a strong surf.

20. Cross-bedding should be common in

A. sediment deposited by streams.

B. sediment deposited from bodies of still water.

C. organic sediments deposited in swampy areas.

D. ancient reefs.

21. Radiometric dates have been attached to the stratigraphic time scale by the determination of radiometric ages of

A. igneous rocks younger and older than sedimentary formations.

B. shales.

C. fossil skeletons.

D. metamorphosed sediments.

22. A disconformity represents

A. an interval of nondeposition followed by submergence.

B. an interval of nondeposition, or of erosion, or both.

C. a time period for which no record exists.

D. all of the above.

23. Metamorphism is the process by which existing rocks are changed by

A. color and hardness.

B. melting and crystallization from that melt.

C. the weathering process at or near the surface.

D. the application of heat, pressure and shearing.

24. Metamorphic rocks can usually be distinguished from igneous and sedimentary rocks in that their constituent grains

A. are rounded and cemented together.

B. interlock, forming a continuous mosaic.

C. tend to be lined up in a particular direction or plane.

D. have quite different chemical compositions.

25. The chemical compositions of metamorphic rocks mainly depend on the

A. temperature to which they have been raised.

B. pressures to which they have been subjected to.

C. effects of both temperature and pressure.

D. composition of the original igneous or sedimentary rocks.

26. Metamorphism can affect

A. only igneous rock.

B. any younger igneous and sedimentary rock.

C. any younger igneous and metamorphic rock.

D. any older igneous, sedimentary, or metamorphic rocks.

27. A major cause of metamorphism on the Moon is

A. contact metamorphism.

B. cold temperatures.

C. meteor impacts.

D. thermal metamorphism.

E. water reactions.

28. The metamorphic rock associated with the highest temperature and pressure is

A. basalt.

B. marble.

C. slate.

D. gneiss.

29. Which of the following rocks is the metamorphic product of limestone?

A. Hornfels.

B. Gneiss.

C. Marble.

D. Quartzite.

E. Granite.

30. Metamorphic processes may convert shale to

A. slate.

B. schist.

C. gneiss.

D. all of the above.

E. none of the above.

31. Quartzite is the metamorphic product of

A. sandstone.

B. granite.

C. limestone.

D. shale.

E. rhyolite.

32. Mylonite is

A. intensely sheared rock.

B. metamorphosed limestone.

C. a hydrothermal metamorphic rock.

D. produced by contact metamorphism of shale.

33. Which of the following rocks is most likely to indicate that partial melting took place?

A. Migmatite.

B. Quartzite.

C. Hornfels.

D. Muscovite schist.

E. Slate.

34. Many rocks produced by contact metamorphism show little or no foliation platy or elongated crystals are randomly oriented because

A. very little deformation accompanies the metamorphism.

B. this type of metamorphism occurs at very high temperatures.

C. this type of metamorphism occurs at very low pressures.

D. none of the original minerals recrystallized during the metamorphism.

35. When a magma intrudes into a host rock, the rock immediately adjacent to the margins of the intrusion, thus forming a new rock, what is the general term for this process?

A. Schistosity formation.

B. Contact (thermal) metamorphism.

C. Deposition alteration.

D. Recrystallization.

E. Regional metamorphism.

36. Regional metamorphism is associated with

A. very low pressures.

B. hot springs.

C. lava flows.

D. subduction zones and cores of mountain ranges.

E. deposits of weathered rock.

37. As temperature and pressure increase in regional metamorphism, which of the following does not occur?

A. Water is driven off.

B. Major changes in bulk chemical composition take place.

C. Grain-size of minerals increases.

D. Minerals take up preferred orientations.

38. The Phanerozoic Eon has been subdivided into three eras. These are

A. the Cryptozoic, the Mesozoic, and the Psychozoic.

B. the Paleozoic, the Permian, and the Tertiary.

C. the Paleozoic, the Mesozoic, and the Cenozoic.

D. the Precambrian, the Postcambrian, and the Proterozoic.

39. James Hutton contributed greatly to the study of the Earth when he formulated the Principle of Uniformitarianism which states

A. that geologic processes took place at uniform rates in the past.

B. that geologic processes take place today as they did in the past.

C. that igneous rocks must be older than sedimentary rocks.

D. that there is a uniform evolution of life forms represented in the fossil record.

40. Radiometric dates have been attached to the stratigraphic time scale by the determination of

A. radiometric ages of igneous rocks younger and older than sedimentary formations.

B. radiometric ages of shales.

C. radiometric ages of fossil skeletons.

D. radiometric ages of metamorphosed sediments.

41. Most radiometric dates on rocks represent the last time the rock

A. crystallized from a magma or metamorphosed.

B. was deposited.

C. was eroded.

D. became cemented.

42. The Principle of Fossil Succession

A. can be used to establish relative ages.

B. can be applied to the correlation of sedimentary rock strata.

C. states that fossils at the bottom of a sedimentary rock sequences are oldest.

D. all of the above.

43. The Earth is thought to be 4.5 billion years old based on

A. the age of the oldest rocks on Earth.

B. the energy level of the sun, today.

C. the crater density of the lunar highlands.

D. the radiometric ages of meteorites and lunar rocks.

44. The oldest rocks on the sea floor are about

A. 20 million years old.

B. 200 million years old.

C. 600 million years old.

D. 3 billion years old.

E. 4.5 billion years old.

1. Mountains / Conglomerates

2. Shale / Slate / Gneiss

3. Sandstone / Granite

4. Acid rain / Chemical weathering

5. Sedimentary rocks / Cement

1. Discuss the geologic circumstance that can be inferred from each of the following rocks and geologic structures.

A. A well-rounded conglomerate mixed with coarse, rounded sand.

B. A limestone with abundant fossil clams and snails.

C. A slate.

D. A graben, a valley or basin with normal faults on both sides.

Note: Be sure to discuss the basis for your interpretations. Use sketches or diagrams to illustrate your discussion.

2. Briefly explain how foliation is created during metamorphism.

3. What is regional metamorphism and how and where does it occur? Explain briefly. In metamorphism, pre-existing rocks are transformed to new metamorphic rocks with different structures and mineral combinations. Describe the progressive changes that might occur in a shale (very fine-grained clastic rock) if it was subjected to regional metamorphism. Several metamorphic rock types can be produced from shale, and you will obtain full credit by listing as many of them as possible.

4. Contact, regional, dynamic. To what process do these terms refer? Define them, and give examples of rocks produced by each of the three types of the process. Which one of the three is most common and therefore most important?