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GEOL 10: Environmental Geology
Mid-Term I
(1) 2 pts. A ________ is a well-tested and widely accepted view that best explains certain scientific
observations.
A) law B) hypothesis C) generalization D) theory
(2) 2 pts. The currently accepted age of the Earth is ________ years.
A) 4.6 billion B) 4.6 thousand C) 6.4 million D) 6.4 trillion
(3) 2 pts. Which is the thinnest Earth layer?
A) Continental Crust
B) Oceanic Crust
C) Mantle
D) Core
(4) 3 pts. Describe thermal convection. Include the source of heat, where this heat goes, what it does to
Earth’s materials, and what those materials do. Include information about the two following questions:
Why do the Earth materials rise? Why do they fall?
(5) 2 pts. What are Earth’s layers based upon physical properties?
A) core, mantle, lithosphere
B) core, mantle, crust
C) core, mesosphere, asthenosphere, lithosphere
D) inner core, outer core, mesosphere, asthenosphere, lithosphere
(6) 2 pts. What are Earth’s layers based upon mineralogy/chemical properties?
A) core, mantle, lithosphere
B) core, mantle, crust
C) core, mesosphere, asthenosphere, lithosphere
D) inner core, outer core, mesosphere, asthenosphere, lithosphere
(7) 2 pts. Sedimentary rocks that are dipping at an angle
A) were always that way.
B) have been uplifted/deformed tectonically.
C) are younger than the fault that cut them.
D) are older than the fault that cut them.
E) A & B
F) B & C
G) B & D
(8) 2 pts. What happens to oceanic crust as it gets older, in the correct order?
A) crust cools, becomes more dense, and sinks B) crust becomes more dense and sinks
C) crust gets more dense, cools, and rises
D) crust heats, becomes less dense, and rises
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GEOL 10: Environmental Geology
Mid-Term I
(9) 2 pts. Oceanic crust rock composition is ____ and Continental crust rock composition is _____.
A) mafic, felsic
B) felsic, mafic
C) algic, felsic
D) mafic, algic
(10) 2 pts. Which is the most dense?
A) continental crust
B) oceanic crust
C) core
D) mantle
(11) 2 pts. Which is the least dense?
A) continental crust
B) oceanic crust
C) core
D) mantle
(12) 2 pts. Which of the following best describes the fundamental concept of superposition?
A) Any sedimentary deposit accumulates on older rock or sediment layers.
B) Older strata generally are deposited on younger strata without intervening, intermediate age strata.
C) Strata with fossils are generally deposited on strata with no fossils.
D) Older fossils in younger strata indicate a locally inverted geologic time scale.
(13) 2 pts. Which of the following best describes the fundamental concept of cross cutting relations?
A) Rocks are younger than a fault if they are cut by the fault.
B) Processes that cut across geological units are older than those geological units.
C) Processes that cut across geological units are younger than those geological units.
D) Fossils are younger than a fault if they are cut by the fault.
(14) 2 pts.________ rocks form by crystallization and consolidation of molten magma.
A) Igneous
B) Primary
C) Sedimentary
D) Indigenous
(15) 2 pts.________ rocks always originate at the surface of the solid Earth.
A) Secondary B) Sedimentary
C) Igneous
D) Metamorphic
(16) 2 pts.________ is the process by which rocks break down in place to produce soils and sediments.
A) Subduction B) Lithification C) Weathering D) Metamorphism
(17) 2 pts. Which one of the following statements is NOT correct?
A) Sedimentary rocks may weather to igneous rocks.
B) Igneous rocks can undergo metamorphism.
C) Magmas crystallize to form igneous rocks.
D) Metamorphic rocks may melt to magma.
(18) 2 pts. An unconformity is a buried ________.
A) surface of erosion separating younger strata above from older strata below
B) fault or fracture with younger strata above and older strata below
C) surface of erosion with older strata above and younger strata below
D) fault or fracture with older rocks above and younger rocks below
(19) 2 pts. Which of the following best characterizes an angular unconformity?
A) Horizontal lava flows lie below the unconformity, and horizontal, sedimentary strata lie above.
B) Tilted strata lie below the unconformity with loose, unconsolidated soil above.
C) Tilted strata lie below the unconformity, and bedding in younger strata above is parallel to the
unconformity.
D) It is the discordant boundary between older strata and an intrusive body of granite.
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GEOL 10: Environmental Geology
Mid-Term I
(20) 2 pts. Sandstone strata and a mass of granite are observed to be in contact. Which of the following
statements is correct geologically?
A) The sandstone is younger if it shows evidence of contact metamorphism.
B) The granite is older if it contains inclusions of sandstone.
C) The granite is older if the sandstone contains pebbles of the granite.
D) The sandstone is younger if the granite contains sandstone inclusions.
(21) 2 pts. Assume that you have just examined several flat-lying sedimentary layers. After much study
you determine that there is a considerable span of time for which no sedimentary rock layer exists at
this site. You have just discovered a(n) ________.
A) disconformity
B) example of cross-cutting relationships
C) series of conformable strata
D) angular unconformity
(22) 2 pts. What fundamental concept states that in a horizontal sequence of conformable sedimentary
strata, each higher bed is younger than the bed below it?
A) theory of correlative deposition
B) law of original correlation
C) law of superposition
D) theory of superstition
(23) 2 pts. The half-life of carbon-14 is about 6000 years. Assume that a sample of charcoal formed by
burning of living wood 15,000 years ago. How much of the original carbon-14 would remain today?
A) between 33% and 50%
B) between 25% and 50%
C) more than 50%
D) between 12.5% and 25%
(24) 2 pts. In the chart of radioactive decay
shown at the right:
(a) how many half-lives have elapsed by this
time? __2__
(b) how many half-lives have elapsed by this
time? __3__
(25) 2 pts. Which of the following energy
sources is thought to drive the lateral motions
of Earth's lithospheric plates?
A) electrical and magnetic fields localized in the
inner core
B) swirling movements of the molten iron
particles in the outer core
C) export of heat from deep in the mantle to
the top of the asthenosphere
D) gravitational attractive forces of the Sun and
Moon
(26) 2 pts. Pull-apart rift zones are generally
associated with a ________ plate boundary.
A) convergent
B) divergent
C) transform
D) all plate boundaries
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GEOL 10: Environmental Geology
Mid-Term I
(27) 2 pts. New oceanic crust and lithosphere are formed at ________.
A) divergent boundaries by submarine eruptions and intrusions of basaltic magma
B) convergent boundaries by submarine eruptions and intrusions of basaltic magma
C) divergent boundaries by submarine eruptions and intrusions of rhyolitic magma
D) convergent boundaries by submarine eruptions and intrusions of rhyolitic magma
(28) 2 pts. The ________ is an example of an active, continent-continent collision.
A) westward movement of the South American plate over the Nazca plate
B) Arabian Peninsula slamming into North Africa under the Red Sea
C) northern movement of Baja California and a sliver of western California toward the Hawaiian Islands
D) northward movement of India into Eurasia
(29) 2 pts. Linear, magnetic patterns associated with mid-ocean ridges are configured as ________.
A) reversed magnetizations along the rift valleys and normal magnetizations along the ridge
B) normal and reversed magnetized strips roughly parallel to the ridge
C) normal and reversed magnetized strips roughly perpendicular to the ridge axis
D) concentric circles about a rising plume of hot mantle rocks and magma
(30) 2 pts. The distance
between the modern Hawaii
Volcano (Mauna Loa = 0 years
old) and the island that is
circled is 3,200 km. What is the
plate motion rate for the past
30 million years? (Round your
answer to the nearest mm.)
A. 156 mm/year
B. 458 mm/year
C. 107 mm/year
D. 352 mm/year
(31) 2 pts. In the diagram
below, label each illustration
with the correct type of plate
boundary.
Convergent, Transform, Divergent
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GEOL 10: Environmental Geology
Mid-Term I
(32) 3 pts. List the units and processes from oldest to youngest.
(33) 3 pts. Using the figure at the right,
knowing the stream is 1,000 years old,
what is the slip rate on the fault?
A) 100 mm/yr
C) 1 mm/yr
B) 10 mm/yr
D) 1,000 mm/yr
(34) 2 pts. Which wave is the last to
reach the seismograph station?
A) P-waves
B) S-waves
C) Surface waves
D) Body waves
E) All of the waves reach the station at
the same time
(35) 2 pts. Which of the following is true about seismographs taken far from the epicenter of the
earthquake as compared to those that are closer?
A) There will not be any P-waves detected
B) There will not be any S-waves detected
C) The P and S waves will be closer together
D) The P and S waves will be further apart
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GEOL 10: Environmental Geology
Mid-Term I
The following five questions refer to the faults in figure below.
(36) 2 pts. Which of
the above choices is
a true reverse fault?
i. A
ii. B
iii. C
iv. D v. E
vi. F
(37) 2 pts. Which of
the above choices is
a true normal fault?
i. A
ii. B
iii. C
iv. D v. E
vi. F
(38) 2 pts. Which is a
blind thrust fault?
i. A
ii. B
iii. C
iv. D v. E
vi. F
(39) 2 pts. Which is a right-lateral, strike-slip fault?
i. A
ii. B
iii. C
iv. D
v. E
vi. F
(40) 2 pts. Which of the following pairs of faults are the results of compressive stresses?
i. a&b
ii. b&c
iii. d&e
iv. none of these
(41) 2 pts. What causes earthquakes in San Francisco?
A) Dip-slip faults from Subduction
B) Transform faults
C) Dip-slip faults from divergent plate boundaries
D) Dip-slip faults from convergent plate boundaries
E) These are intraplate earthquakes
(42) 2 pts. The __________ is measured in cross-sectional view as the angle of inclination from
horizontal of a tilted rock layer, and _______ is viewed in map view as the compass bearing of the rock
layer where it intersects a horizontal plane.
A) strike; strike
B) dip; dip
C) strike; dip
D) dip; strike
E) strike and dip; strike and dip
(43) 2 pts. Faults on which the dominant forces are extensional are recognized by the separation of the
pulled-apart rock layers in a zone of omission. These are ____________.
A) reverse faults
B) thrust faults
C) transform faults
D) strike-slip faults
E) normal faults
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GEOL 10: Environmental Geology
Mid-Term I
Use the plot to the right for the next 2
questions. There are two sets of data
plotted, one on the left (blue) and one on
the right (red).
(44) 2 pts. What are the different data
sets, in order, from left to right?
A) P-wave, Love-wave
B) Raleigh-wave, P-wave
C) S-wave, P-wave
D) S-wave, Love-wave
(45) 2 pts. What does the blue curve on
the left tell us about the outer core?
A) The outer core is liquid and P-waves cannot travel through liquid.
B) The outer core is liquid and S-waves cannot travel through liquid.
C) The outer core is solid and P-waves cannot travel through solid.
D) The outer core is solid and P-waves cannot travel through solid.
(46) 2 pts. Using the plot at the right,
choose the correct names for the
seismic waves labeled a, b, and c.
i. Surface-waves, P-wave, S-wave
ii. P-wave, S-wave, Surface-waves
iii. S-wave, P-wave, Surface-waves
iv. P-wave, Surface-waves, S-wave
(47) 2 pts. The Elastic Rebound Theory is made up of four parts. Which of the following is in the correct
sequential order?
A) stress, rebound, rupture, strain
B) rebound, rupture, stress, strain
C) stress, strain, rupture, rebound
D) none of these is correct
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