Earth Science 1
Terms in this set (58)
What ancient reptile lived in South America and South Africa during the late Paleozoic?
In the early part of the 20th century, who argued forcefully for continental drift?
The former late Paleozoic super continent is known as?
Today, what is in about the same place as during the later Paleozoic time?
Which of the following paleoclimatic evidence supports the idea of the late Paleozoic supercontinent in the southern hemisphere?
tillites (rocks formed by glacers) in South Africa and South America
What is an example of an active, continent-continent collision
northward movement of India into Europe
Pull-apart rift zones are generally associated with what type of plate boundary?
The temperature below which magnetic material can retain a permanent magnetization?
A very long-lived magma source located deep in the mantle?
Linear, magnetic patterns associated with mid-ocean ridges are configured as?
Normal and reversed magnetized strips roughly parallel to the ridge
What is the logical evolutionary analog of the African rift valleys 10,000,000 years from now?
The Red Sea
A typical rate of seafloor spreading in the Atlantic Ocean is?
2 centimeters per year
Which of the following energy sources is thought to drive the lateral motions of the 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 Wenger could not?
identify a mechanism capable of moving continents
All of the following are evidence supporting Plate tectonics except?
changes in the moon's orbit due to shifting plates
What was never proposed as evidence supporting the existence of Pangaea?
islands of Precambrian rocks along the mid-Atlantic ridge
Which of the following most accurately describes the Hawaiian Island volcanoes?
shield volcanoes fed by a long-lived hot spot below the Pacific lithospheric plate
What 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, oceanic lithosphere sinks into the mantle at?
subduction zones along convergent plate boundaries
Deep ocean trenches are superficial evidence for?
sinking oceanic lithosphere into the mantle at the subduction zone
A transform plate boundary is characterized by?
a deep, vertical fault along which two plates slide past one another in opposite directions
What is a fundamental assumption underlying plate tectonic theory?
Earth's diameter has been essentially constant over time
The modern day Red Sea is explained by Plate Tectonics:
a rift zone that may eventually open into a major ocean if Arabia & Africa continue to separate
Mount St. Helen and other Cascade volcanoes are:
young, active stratovolcanoes 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
Aleutian Islands occur at a?
convergent boundary on a volcano arc above a North West subducting Pacific plate
What most effectively outlines the edges of the lithospheric plates?
lines of earthquake epicenters
Deep-oceanic trenches are the most abundant around the rim of what ocean basin?
The Pacific Ocean basin
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
Who first related the symmetrical magnetic patterns in seafloor basalts to seafloor spreading at a mid-oceanic ridge?
Vine and Matthews
Early results of the deep sea drilling project clearly justified what conclusion?
the oceanic basins are relatively young; most ocean based rocks and sediments are Cretaceous or younger in age
a. fossil evidence
b. fit of the continents
a. curie point
c. magnetic poles
a. oceanic ridge
b. seafloor spreading
c. arc volcanoes
c. arc volcanoes
b. island arc
c. volcanic arc
a. slab pull
b. mantle drag
c. ridge pull
d. slab suction
b. mantle drag
Plates are moving apart from one another.
Plates are sliding past one another.
Boundary is normally devoid of volcanoism.
Where lithosphere sinkis into the mantle.
Basaltic volcanoism and seafloor spreading.
Arc of stratovolcanoes and deep floor trenches
where a subduction zone occurs
San Andreas fault
West coast of South America
The oldest rocks on the seafloor are much younger than the oldest rocks on the continents.
Earth's radius and surface are slowly increasing to accommodate the new oceanic crust being formed at mid-oceanic ridges.
Hawaii is the oldest island in the Hawaiian Island chain.
The oldest rocks of the oceanic crust are found in deep oceanic 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.
Rocks of the continental crust are less dense than rocks of the oceanic crust
At times in the past, the polarity of Earth's magnetic field has been reversed.
Average rate of seafloor spreading is 1 meter per year.
Wenger's continental drift hypothesis lacked a viable mechanism to explain continental movement.
The magnetic field poles have generally been close to Earth's rotational poles.
Seafloor spreading rates can be restricted if geologic ages of the magnetic field reversals are independently known.