________ was an ancient reptile that lived in South America and Africa during the late Paleozoic.
In the early part of the twentieth century, ________ argued forcefully for continental drift.
The former late Paleozoic super continent is known as ________.
Today, ________ is in about the same geographic position as during late Paleozoic time.
Which of the following paleoclimatic evidence supports the idea of the late Paleozoic supercontinent in the Southern Hemisphere?
lithified loess (wind-blown) deposits in the deserts of Chile, Australia, and Africa
tillites (rocks formed by glaciers) in South Africa and South America
thick sediments in the Amazon and Congo deltas of South America and Africa
cold water fossils in the deep-water sediments of the South Atlantic abyssal plain
The ________ is an example of an active, continent-continent collision.
Arabian Peninsula slamming into North Africa under the Red Sea
westward movement of the South American plate over the Nazca plate
northern movement of Baja California and a sliver of western California toward the Hawaiian Islands
northward movement of India into Eurasia
Pull-apart rift zones are generally associated with a ________ plate boundary.
all plate boundaries
The temperature below which magnetic material can retain a permanent magnetization is called the ________.
A very long-lived magma source located deep in the mantle is called a ________.
Linear, magnetic patterns associated with mid-ocean ridges are configured as ________.
concentric circles about a rising plume of hot mantle rocks and magma
reversed magnetizations along the rift valleys and normal magnetizations along the ridge
normal and reversed magnetized strips roughly parallel to the ridge
normal and reversed magnetized strips roughly perpendicular to the ridge axis
The ________ is (are) a logical evolutionary analog of the African Rift Valleys ten million years from now.
San Andreas fault
A typical rate of seafloor spreading in the Atlantic Ocean is ________.
2 feet per year
0.1 inches per year
20 feet per year
2 centimeters per year
Which of the following energy sources is thought to drive the lateral motions of Earth's lithospheric plates?
gravitational attractive forces of the Sun and Moon
electrical and magnetic fields localized in the inner core
export of heat from deep in the mantle to the top of the asthenosphere
swirling movements of the molten iron particles in the outer core
The continental drift hypothesis was rejected primarily because Alfred Wegener could not ________.
find geologic similarities on different continents
disprove competing theories that were more accepted by scientists
identify a mechanism capable of moving continents
all of the above
All of the following are evidence supporting the theory of plate tectonics except for ________.
changes in the Moon's orbit due to shifting plates
ocean floor drilling
________ was never proposed as evidence supporting the existence of Pangaea.
Geometrical fit between South America and Africa
Islands of Precambrian rocks along the Mid-Atlantic Ridge
Late Paleozoic glacial features
Similar fossils on different continents
Which one of the following most accurately describes the volcanoes of the Hawaiian Islands?
stratovolcanoes associated with subduction and a convergent plate boundary
shield volcanoes fed by a long-lived hot spot below the Pacific lithospheric plate
shield volcanoes associated with a mid-Pacific ridge and spreading center
stratovolcanoes associated with a mid-Pacific transform fault
Which of the following statements apply to the asthenosphere, but not the lithosphere?
zone in the upper mantle that deforms by plastic flowage
cool, rigid layer of crust and upper mantle that forms the tectonic plates
deforms mainly by brittle fracturing and faulting
partial melting of rising granitic plumes produces huge volumes of basaltic magma
New oceanic crust and lithosphere are formed at ________.
divergent boundaries by submarine eruptions and intrusions of rhyolitic magma
convergent boundaries by submarine eruptions and intrusions of rhyolitic magma
divergent boundaries by submarine eruptions and intrusions of basaltic magma
convergent boundaries by submarine eruptions and intrusions of basaltic magma
Cooler, older, oceanic lithosphere sinks into the mantle at ________.
subduction zones along convergent plate boundaries
transform fault zones along divergent plate boundaries
rift zones along mid-ocean ridges
sites of long-lived, hot spot volcanism in the ocean basins
Deep ocean trenches are surficial evidence for ________.
rifting beneath a continental plate and the beginning of continental drift
sinking of oceanic lithosphere into the mantle at a subduction zone
rising of hot asthenosphere from deep in the mantle
transform faulting between an oceanic plate and a continental plate
A transform plate boundary is characterized by ________.
stratovolcanoes on the edge of a plate and shield volcanoes on the adjacent plate
two converging oceanic plates meeting head-on and piling up into a mid-ocean ridge
a divergent boundary where the continental plate changes to an oceanic plate
a deep, vertical fault along which two plates slide past one another in opposite directions
Which one of the following is an important fundamental assumption underlying the plate tectonic theory?
Earth's magnetic field originates in the outer core.
Earth's diameter has been essentially constant over time
Radioactive decay slows down at the extreme pressures of the inner core.
Earth's ocean basins are very old and stable features
The modern-day Red Sea is explained by plate tectonics theory because it is ________.
a tiny remnant of a once immense ocean that was closed as Africa moved toward Asia
the site of a transform fault along which Arabia is moving away from Africa
a rift zone that may eventually open into a major ocean if Arabia and Africa continue to separate
a rare example of a two-continent subduction zone where the African continental plate is sinking under the Arabian continental plate
Mount St. Helens and the other Cascade volcanoes are ________.
young, active stratovolcanoes built on a continental margin above a sinking slab of oceanic lithosphere
a row of young, active, shield volcanoes built as western North America moved over a hot spot deep in the mantle
old, deeply eroded stratovolcanoes built before the Pacific Ocean existed
old, deeply eroded, basaltic shield volcanoes built when western North America was over the present-day site of the Hawaiian hot spot
The volcanoes and deep valleys of east Africa are related to a ________.
continental rift along which parts of the African continent are beginning to slowly separate
fault allowing Arabia to slip westward past east Africa and penetrate into Turkey
transform fault aligned with the Red Sea carrying the Arabian and African blocks in opposite directions
continental collision zone between Africa and the Zagros Mountains along the southern margin of Eurasia
The Aleutian Islands occur at a ________.
convergent boundary on a volcanic arc above a northward-subducting Pacific plate
transform boundary where North America has moved towards Alaska
divergent boundary where shield volcanoes are forming
convergent, continental margin with uplifted fault blocks, much like those of the Basin and Range Province
________ most effectively outline the edges of the lithospheric plates.
Lines of active stratovolcanoes
Margins of the continental shelves
The locations of deep mantle hot spots
Lines of earthquake epicenters
Deep-oceanic trenches are most abundant around the rim of the ________ ocean basin.
Where would you drill to recover samples of the oldest basalts of the oceanic crust, which are Jurassic in age?
crest of the East Pacific, mid-ocean ridge
oceanic side of the Aleutian trench
just offshore from the Hawaiian Islands
Mid-Atlantic Ridge under Iceland
________ first related the symmetrical magnetic patterns in seafloor basalts to seafloor spreading at a mid-ocean ridge.
Evans and Novak
Vine and Matthews
Matthews and Marks
Wegener and Wilson
Early results of the Deep Sea Drilling Project clearly justified the conclusion that ________.
the oceans have not always contained most of Earth's water
the ocean basins are relatively young; most ocean basin rocks and sediments are Cretaceous or younger in age
Proterozoic rocks are found only as seamounts in the deepest parts of the ocean basins
the youngest sediments were deposited directly on the oldest seafloor basalts
Choose the option which does not fit the pattern.
fit of the continents
Choose the option which does not fit the pattern.
Choose the option which does not fit the pattern
The oldest rocks on the seafloor are much younger than the oldest rocks on the continents.
Earth's radius and surface area are slowly increasing to accommodate the new oceanic crust being formed at mid-ocean ridges.
Hawaii is the oldest island of the Hawaiian Island chain.
The oldest rocks of the oceanic crust are found in deep ocean trenches far away from active, mid-ocean ridges
As the South Atlantic basin widens by seafloor spreading, Africa and South America are moving closer together.
In general, rocks of the continental crust are less dense than rocks of the oceanic crust.
During various times in the geologic past, the polarity of Earth's magnetic field has been reversed.
The rate of seafloor spreading is, on the average, about one meter per year.
Wegener's continental drift hypothesis was weakened because a viable mechanism for moving the continents was lacking.
During the geologic past, the magnetic field poles have generally been very close to Earth's rotational poles.
Seafloor spreading rates can be estimated if the geologic ages of the magnetic field reversals are independently known.
The volcanoes of Hawaii are localized above a deep mantle hot spot; they are not part of the East Pacific oceanic ridge
Iceland is a good example of an island arc, formed from an oceanic-oceanic plate collision.
An extensive, late Paleozoic glaciation affected southern India, southern Africa and southeastern South America.
The Himalayan Mountains are the tectonic product of a collision between India and Eurasia that began in Eocene time and still continues.