1. Which magma is most likely to quench (congeal) to a natural glass?
A) highly viscous; cools quickly
B) highly viscous; cools slowly
C) highly fluid; cools slowly
D) highly fluid; cools quickly
2. The sizes, shapes, and arrangements of mineral grains in an igneous rock are known as ___________.
A) silica content
C) mineral content
D) Bowen's reaction series
3. Visible quartz and potassium feldspar grains are the main constituents in a _________.
4. ___________is a volcanic rock that is extremely vesicular and glassy.
5. What is the main difference between a conglomerate and a sedimentary breccia?
A) breccia clasts are angular; conglomerate clasts are rounded
B) a breccia is well stratified; a conglomerate is poorly stratified
C) breccia clasts are the size of baseballs; conglomerate clasts are larger
D) breccia has a compacted, clay-rich matrix; conglomerate has no matrix
6. Which statement concerning sedimentary rocks is not true?
A) they may contain fossils that provide clues about ancient life forms
B) they probably show some evidence of stratification
C) they were originally deposited at depth below the bottom of the sea
D) they are composed of particles and constituents derived from weathering and erosion of other rocks
7. Which type of limestone consists mainly of very tiny (microscopic), marine fossils composed of calcite?
8. ___________is the most common type of chemical sedimentary rock.
C) Phosphate rock
D) Quartz sandstone
9. Coal beds originate in ___________.
A) shallow lakes in a dry, desert region
B) channels of fast-moving streams
C) deep, marine basins below wave action
D) freshwater coastal swamps and bogs
10. Tektites originate in what metamorphic environment?
A) low pressure and high temperature associated with volcanism
B) high temperatures associated with meteorite impacts
C) very high pressures and temperatures associated with deep subduction
D) high temperatures and shearing stresses in an oceanic-crust transform fault
11. Which of the following statements concerning slate is not true?
A) forms from shales and mudstones
B) has abundant, coarse-grained mica
C) rock cleavage is common
D) sedimentary features may be visible
12. ____________is a strong, parallel alignment of coarse mica flakes and/or of different mineral bands in a metamorphic rock.
A) Rock cleavage
C) Stress streaking
13. ___________forms from the metamorphism of limestone or dolostone.
14. What is the major source of heat for contact metamorphism?
A) deep burial and heat from the Earth's interior
B) heat from grinding and shearing on faults
C) heat from spontaneous decomposition of micas and feldspars
D) heat from a nearby magma body
15. What major change occurs during metamorphism of limestone to marble?
A) calcite grains grow larger and increase in size
B) clays crystallize to micas, forming a highly foliated, mica-rich rock
C) limestone grains react to form quartz and feldspars
D) calcite grains are dissolved away leaving only marble crystals