____ was an ancient reptile that lived in South America during the late Paleozoic.
Mesosaurus
In the early part of the 20th century, ____ argued forcefully for continental drift.
Alfred Wegener
The former late Paleozoic super continent is known as ____.
Pangaea
Today, ____ is in about the same geographic position as during late Paleozoic time.
Antarctica
What paleoclimatic evidence supports the idea of the late Paleozoic supercontinent in the Southern hemisphere?
tillites (rocks formed by glaciers) in South Africa and South America.
Pull -apart rift zones are generally associated with a ____ plate boundary.
divergent
The temperature below which a magnetic material can retain a permenant magnetization is called the ____.
Curie point
A very long-lived magma source located deep in the mantle is called a ____.
hot spot
Linear, magnetic patterens associated with mid-ocean ridges are configured as ____.
normal and reversed magnitized strips roughly parallel to the ridge.
The ____ is(are) a revolutionary analog of the African Rift Valleys ten million years from now.
Red Sea
A typical rate of seafloor spreading in the Atlantic Ocean is ____.
2 centimeters per year.
What energy source is thought to drive the lateral motions of earth's lithospheric plates?
export of heat from deep in the mantle to the top of the asthenosphere.
The continental drift hypothesis was rejected primarily because Alfred Wegener could not ____.
identify a mechanism capable of moving continents.
What is not evidence that supports the theory of plate tectonics?
changes in the moon's orbit due to shifting plates.
____ was never proposed as evidence supporting the existence of Pangaea.
Islands of Precambrian rocks along the Mid-Atlantic ridge.
What most accurately describes the volcanoes of the Hawaiian Islands?
sheild volcanoes fed by a long-lived hot spot below the Pacific lithosphere plate.
What statement applies to the asthenosphere but not the lithosphere?
zone in the upper mantle that deforms by plastic flowage.
New oceanic crust and lithosphere are formed at ____.
divergent boundaries by submarine eruptions and intrusions of basaltic magma.
Cooler, older, ocaenic lithosphere sinks into the mantle at ____.
subduction zones along convergent plate boundaries.
Deep ocean trenches are surficial evidence for ____.
sinking of oceanic lithosphere into the mantle at a subduction zone.
A transform plate boundary is characterized by ____.
a deep, verticle vault along which two plates slide past one another in opposite directions.
What is an important fundamental assumption underlying the plate tectonic theory.
Earth's diameter has been essentially constant over time.
The modern-day Red Sea is explained by tectonics theory because it is ____.
a rift zone that may eventually open into a major ocean if Arabia and Africa continue to separate.
Mount St. Helens and other cascade volcanoes are ____.
young, active strato volcanoes built on a continental margin above a sinking slab of oceanic lithosphere.
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.
The Aleutian Islands occur at ____.
convergent boundary on a volcanic arc above a northward-subconducting Pacific plate.
____ most effectively outline the edges of the lithospheric plates.
Lines of earthquake epicenters.
Deep-oceanic trenches are most abundant around the rim of the ____ ocean basin.
Pacific
Where would you drill to recover samples of the oldest basalts of the oceanic crust, which are Jurassic in age?
oceanic side of the Aleutian trench.
____ first related the symmetrical magnetic patterns in seafloor basalts to seafloor spreading at a mid-ocean ridge.
Vine and Mathews
Early results of the deep Sea Drilling Project clearly justified the conclusion that ____.
the ocean basins are relatively young; most ocean basin rocks and sediments are Cretaceous or younger.
divergent
plates are moving apart from one another.
convergent
plates are moving toward one another
transform
plates are sliding past one another horizontally
This boundary is normally devoid of volcanism
transform plate boundary
Where lithosphere is sinking into the mantle
convergent plate boundary
Characterized by basaltic volcanism and seafloor spreading
divergent plate boundary
characterized by arcs of stratovolcanoes and deep-ocean trenches.
convergent plate boundary
The Mid-Atlantic Ridge is a ____.
divergent plate boundary
Where subduction zones occur
convergent plate boundary
The San Andreas fault is a ____.
transform plate boundary
The west coast of South America is a ____.
convergent plate boundary.