Download rock and mineral exam

PRACTICE EXAM 1
GEOL 131
CHAPTER 2 – MINERALS
1. What is a mineral’s effervescence?
a. Its chemical composition
b. The way it breaks
c. Its reactivity to hydrochloric acid
d. Its color in powdered form
2. Which of the following is a mineral? (Mark only one answer.)
a. Fingernail
b. Volcanic glass
c. Wood
d. Coal
e. None of the above
3. To be considered a mineral, a substance must have a defined chemical composition.
a. True
b. False
4. The electrons in an atom’s outermost electron shell are called variable electrons.
a. True
b. False
5. The elements in a silicate tetrahedron are
a. Sodium and oxygen
b. Silicon and oxygen
c. Silicon and carbon
d. Potassium and carbon
6. In the silicate tetrahedron, silicon bonds with other tetrahedra to form silicate
structures
a. True
b. False
7. Muscovite’s formula is KAl2(AlSi3O10)(OH) 2. It belongs to the ____ group.
a. Oxide
b. Silicate
c. Sulfide
d. Halide
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8. Which of the following is not a physical property of minerals?
a. Texture
b. Color
c. Streak
d. Hardness
Label the silicate structure shown in each of the following diagrams. Use the names in
the list following the diagrams (not all names will be used):
9.
10.
11.
A.
B.
C.
D.
Single-chain
Double-chain
Sheet
3-D network
12. Which of the following is a member of the sulfate mineral group?
a. Galena- PbS
b. Sulfur - S
c. Calcite – CaCO3
d. Anhydrite – CaSO4
13. Dark silicate minerals are high in
a. Aluminum and potassium
b. Carbon and oxygen
c. Silicon and lithium
d. Iron and magnesium
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CHAPTER 3 – MAGMA AND IGNEOUS ROCKS
14. All igneous rocks form by the cooling and crystallization of magma within the Earth’s
crust.
a. True
b. False
15. Magma cooling rate determines what about igneous rocks?
a. The composition
b. The cleavage
c. The texture (size of crystals)
d. Shape of crystals
e. None of the above
16. Lava from a Hawaiian volcano crystallizing into basalt is an example of ____ igneous
rock formation.
a. Intrusive
b. Extrusive
c. Porphyritic
d. Felsic
e. None of the above
For each blank box, write the correct rock name from the list on the next page.
FELSIC
INTERMEDIATE
MAFIC
PHANERITIC
APHANITIC
GLASSY
VESICULAR
PYROCLASTIC
A.
B.
C.
D.
E.
F.
G.
H.
I.
GABBRO
TUFF
GRANITE
SCORIA
ANDESITE
OBSIDIAN
RHYOLITE
BASALT
DIORITE
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17. Volcanic glass forms when magma is cooled instantly (quenched), and its atoms form
an ordered atomic structure.
a. True
b. False
18. Most magmas are generated by adding enough heat to rocks to cause them to melt.
a. True
b. False
19. In hydration melting, water is added to mantle rock, triggering melting. The water
comes from…
a. Heating of a subducting crustal plate
b. The Earth’s core
c. A geyser
d. Metamorphism of quartz crystals
20. Decompression melting occurs when solid mantle rock is pushed deeper into the
mantle.
a. True
b. False
21. According to Bowen’s Reaction Series, which of the following minerals will crystallize
last in a cooling magma?
a. Quartz
b. Biotite
c. Pyroxene
d. Olivine
22. A magma composed of 25% oxygen, 25% silicon, 25% iron, and 25% potassium
begins to cool and crystallize. All of the iron and silicon in the magma go into the first
mineral crystals to form, which accumulate at the bottom of the magma chamber. The
iron and silicon are therefore removed from the magma. What is the composition of
the remaining magma?
a.
b.
c.
d.
20% oxygen, 20% potassium
50% oxygen, 50% potassium
12.5% oxygen, 12.5% potassium
10% iron, 90% silicon
23. What is the name of the process described in the previous question?
a. Crystal settling
b. Magma mixing
c. Assimilation
d. None of the above
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CHAPTER 6 – SEDIMENTARY ROCKS
24. Which type of rock is held together mainly by compaction?
a. Graywacke
b. Shale
c. Conglomerate
d. Breccia
Indicate whether each rock named below is detrital or chemical. If detrital, mark “A”, if
chemical, mark “B”.
25. Graywacke
26. Breccia
27. Oolitic limestone
28. Travertine
Match each rock name with the correct description.
29. Conglomerate
30. Micrite
31. Arkose
32. Chalk
A.
B.
C.
D.
microscopic calcite plankton shells
sandstone type with significant feldspar component
inorganic limestone formed by precipitation of calcite
gravel-size, rounded sediment grains
33. Most detrital sedimentary rocks form by the precipitation of mineral crystals from
solution.
a. True
b. False
34. The salt deposits beneath the Detroit area are a type of
a. Sandstone
b. Limestone
c. Chalk
d. Chert
e. None of the above
Match each sedimentary rock to the environment in which it forms. Each environment will
be used only once.
35. Breccia
36. Arkose
37. Oolitic limestone
38. Chalk
39. Coal
A.
B.
C.
D.
E.
Swamp
Desert
Shallow ocean
Mountain stream channel
Deep ocean
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40. Which sedimentary structure(s) can be used to determine whether a bed has been
overturned? Circle all that apply.
a. Cross-bedding
b. Strata
c. Ripple marks
d. Mudcracks
CHAPTER 7 – METAMORPHIC ROCKS
41. Which of the following rock types can serve as a parent rock?
a. Granite
b. Schist
c. Travertine
d. All of the above
e. None of the above
42. Which of the following is one of the processes that can occur during metamorphism?
a. Rotation of crystals into parallel alignment
b. Partial melting
c. Crystal settling
d. Cementation
43. The three agents of metamorphism are
a. Heat, pressure, and burial
b. Burial, regional, and hydrothermal
c. Heat, chemically active fluids, and pressure
d. Radioactivity, contact, and impact
44. Which metamorphic agent is the most critical?
a. Pressure
b. Burial
c. Contact
d. Radioactivity
e. Heat
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45. Which of these sketches accurately represents differential stress?
a.
b.
c. Neither of the above
46. Which of the following is not a type of foliation?
a. Schistosity
b. Slaty cleavage
c. Gneissic banding
d. All of the above are types of foliation
47. Which environment is high temperature but low pressure?
a. Hydrothermal
b. Regional
c. Contact
d. Impact
48. Which metamorphic environment produces the most metamorphic rock?
a. Regional
b. Contact
c. Impact
d. Hydrothermal
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