110) Areas of crustral collision and subduction occur along
A) divergent boundaries.
B) areas of seafloor spreading.
C) transform boundaries.
D) convergent boundaries.
111) Convergent plate boundaries are characteristic of
A) sea-floor spreading centers.
B) collision zones between plates.
C) lateral motions of plates.
D) all plate boundaries.
112) Areas of upwelling material from the mantle to form new seafloor occur along
A) divergent boundaries.
B) areas of seafloor spreading.
C) transform boundaries.
D) convergent boundaries.
113) Divergent plate boundaries are characteristic of
A) sea-floor spreading centers.
B) collision zones between plates.
C) transform plate boundaries.
D) all plate boundaries.
114) Areas where plates slide past one another, usually are right angles to a seafloor spreading
are
A) divergent boundaries.
B) areas of seafloor spreading.
C) transform boundaries.
D) convergent boundaries.
115) Transform faults along plate boundaries are typically associated with
A) sea-floor spreading centers.
B) subduction zones.
C) volcanism.
D) earthquake activity.
116) ________ are sites of upwelling of magma from the mantle independent of plate
boundaries.
A) Hot spots
B) Subduction zones
C) Transform faults
D) Mid-ocean ridges
117) Plate boundaries are associated with
A) earthquakes.
B) volcanoes.
C) subduction.
D) rifting.
E) All of these are correct.
118) Which of the following is not correct regarding geothermal energy?
A) It is the product of exogenic processes.
B) It’s in use in Iceland, Japan, and California.
C) Used geothermal water can be returned to aquifers via injection wells.
D) It can be used to produce both heat and electricity.
119) The Hawai’ian Islands were formed as a result of
A) a rising plume of magma from the mantle.
B) an oceanic-oceanic plate collision.
C) a continental-oceanic plate collision.
D) activity along a mid-ocean ridge.
120) Which of the following is not correct?
A) The Hawai’ian island chain will subduct in approximately 40 my.
B) The newest Hawai’ian island, Lo’ihi, should reach the surface in around 10,000 years.
C) Measured from the sea floor to its summit, Mauna Kea is the tallest mountain on Earth.
D) The formation of the island of Hawaii took less than 1 my.
121) The geologic cycle is fueled by
A) solar energy.
B) the Earth’s internal heat.
C) both solar energy and the Earth’s internal heat.
D) neither solar energy and the Earth’s internal heat.
122) The three principal cycles composing the geologic cycle include all the following except
A) hydrologic cycle.
B) biogeochemical cycle.
C) tectonic cycle.
D) rock cycle.
123) In terms of the geologic cycle, which of the following is not an exogenic process?
A) weathering
B) erosion
C) deposition
D) subduction
124) In terms of human-environment interaction, which of the following is an example of an
anthropogenic endogenic process contributing to the geologic cycle?
A) strip mining
B) harnessing geothermal energy for electricity development
C) injection wells contributing to earthquake activity
D) rock removal for building contributing to land slides
12.2 True/False Questions
1) True north is a fixed geographic point.
2) The North Magnetic Pole is moving northwest at approximately 55 to 60 km (34-37 mi) per
year.
3) Endogenic processes cause warping, folding, faulting, and uplift of Earth’s surface.
4) Exogenic processes cause warping, folding, faulting, and uplift of Earth’s surface.
5) The oldest rocks on Earth are between 3.96 and 4.3 billion years old.
6) Uniformitarianism assumes the physical processes now activity have been operating
throughout the Earth’s history.
7) Uniformitarianism holds that all geologic change affecting Earth’s surface requires immense
amounts of time to occur.
8) The geological time scale uses equal intervals for dividing the Earth’s long history in a series
of eons, eras, periods, and epochs.
9) Major events in Earth’s history, such as major extinctions, determine the boundaries between
the intervals in the geologic time scale.
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10) The relative age of geologic features is ascertained through the use of radiometric dating.
11) The half-life of a radioactive isotope does not vary.
12) According to currently accepted scientific theories, Earth is never affected by catastrophes.
13) Scientists have direct evidence of the Earth’s internal structure down to upper mantle.
14) The Earth’s interior composition has been inferred by the use of seismic waves.
15) Earth’s magnetic field is generated from within the uppermost mantle and crust.
16) Earth’s magnetic field has reversed nine times in the last four million years.
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17) The core comprises 1/3rd
of the Earth’s mass, but only 1/6th of its volume.
18) The inner core is liquid iron, surrounded by a solid iron outer core.
19) The Moho separates the outer core from mantle.
20) The Moho separates the uppermost mantle from the crust.
21) The mantle represents 80% of the Earth’s volume.
22) The lithosphere lies above the aesthenosphere.
23) The upper mantle is rigid, whereas the aesthenosphere is plastic-like.
24) Just eight natural elements make up over 98% of the Earth’s crust by weight.
25) The crust is thickest under mountains and thinnest under the oceans.
26) The principle of isostasy refers to the vertical movement of Earth’s crust in response to
loading and unloading of weight, such as ice or sediment.
27) A mineral can be either organic or inorganic.
28) Roughly 95% of the Earth’s crust is made up of silicates.
29) Oceanic crust is denser than continental crust.
30) An intrusive igenous rock has finer crystal grains than an extrusive igeneous rock.
31) The formation of clastic sedimentary rock may involve weathering, erosion, transportation,
and deposition.
32) Sedimentary rock may be formed from the shells of organisms containing calcium carbonate.
33) Contact metamorphism involves changes in the texture and minerology of a rock caused by
the extreme heat and pressure of intruding magma.
34) Most sedimentary rocks are derived from preexisting rocks, or from organic materials (such
as bone and shell).
35) Any rock, either igneous or sedimentary, may be transformed into a metamorphic rock, by
going through profound physical and/or chemical changes under increased pressure and
temperature.
36) The rock cycle is fueled both by the hydrologic cycle and the tectonic cycle.
37) The arrangement of continents is permanent with only minor changes wrought by crustal
movement (e.g. earthquakes.)
38) Alfred Wegner’s theory of continental drift was immediately accepted by the scientific
community when it was proposed.
39) Rock assemblages from the east coast in South America and west coast of Africa provide
supporting evidence of the theory of plate tectonics.
40) The continents of the words were once connected, forming a supercontinent called Pangaea.
41) New oceanic crust is formed at mid-ocean ridges.
42) Earthquake and volcanic occurrences do not correlate well with crustal plate boundaries.
43) Ocean floor is destroyed along transform faults.
44) Evidence of reversals in the Earth’s magnetic field is found along areas of seafloor spreading.
45) Though the Earth is 4.6 billion years old, the oldest seafloor is no more than 280 million
years old.
46) The deepest places in the ocean are those in which rifting occurs.
47) Convergent plate boundaries occur in areas of seafloor spreading.
48) Transform plate boundaries are associated with earthquake activity.
49) The geologic cycle is powered both by exogenic and endogenic energy systems.
50) Humans can contribute to both the endogenic and exogenic processes shape the Earth.
12.3 Essay Questions
1) Present the main assumptions of uniformitarianism.
2) Draw or verbally depict a cross-section of Earth from the center to the surface including all of
its major components. Include important physical characteristics, such as the thickness of the
layer, the nature of the rock, approximate temperature, density, and mineral types.
3) Which part of Earth is primarily responsible for Earth’s magnetic field? Why? What are the
characteristics of magnetic reversals? How often do they occur? When will the next one occur,
and what will happen when it does?
4) Describe the three basic rock types, how each are formed, and subcategories of each.
5) Briefly review the history of the theory of plate tectonics. What was Alfred Wegener’s role?
What evidence did he present? Why was his theory not widely accepted initially? What new
evidence led to its later acceptance?
6) Describe the important aspects of the formation and breakup of Pangaea.
7) What is the relationship between seafloor spreading and reversals in the Earth’s magnetic
field?
8) Diagram and label the three types of plate boundaries.
9) Describe the endogenic and exogenic processes involved in the geologic cycle.
10) What are some examples of anthrogenic endogenic and exogenic processes in the geologic
cycle?