Plate Tectonics
In the early part of the 20th century, ________ argued forcefully for continental drift.
Alfred Wegener
Which of the following mountain ranges are examples of continental arcs?
Andes and Cascades
Which of the following statements about divergent boundaries is true?
New ocean crust is created at a divergent boundary.
Which of the following statements regarding transform plate boundaries is not correct?
New oceanic crust is formed at transform plate boundaries.
How do plates move at divergent plate boundaries?
Plates move apart.
How do plates move at convergent plate boundaries?
Plates move toward one another.
How do plates move at transform plate boundaries?
Plates slide past one another.
What would happen to Earth if ocean floor were created at divergent boundaries at a faster rate than it is destroyed at convergent boundaries?
The Earth would increase in volume.
What is the relationship between the crust and lithosphere?
The crust is part of the lithosphere.
When moving away from a divergent boundary in either direction, which of the following statements is true?
The rocks increase in age.
Why are volcanoes NOT found at transform boundaries?
Transform boundaries do not cause changes to the pressure, temperature, or composition of the mantle.
In studies of rock obtained from ocean basins all over Earth, the oldest ages obtained are approximately 200 million years before the present. Why have no older oceanic rocks been discovered?
Due to tectonic activity, rocks on the ocean floor are continually recycled.
________ was a flora that was widely distributed throughout the once contiguous, late Paleozoic, Southern Hemisphere landmass.
Glossopteris
________ was never proposed as evidence supporting the existence of Pangaea
Islands along the Mid-Atlantic Ridge with rocks dating back from 542 million to 2500 million years ago
________ first related the symmetrical magnetic patterns in seafloor basalts to seafloor spreading at a mid-ocean ridge.
Vine and Matthews
Currently the Juan de Fuca plate is interacting with the North American plate where inland volcanoes and deep focus earthquakes are occurring. What type of plate boundary is this?
a convergent plate boundary
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 volcanic arc?
a row of volcanoes that forms on the overriding plate near a subduction zone
Which of the following processes can be observed at the margins of lithospheric plates? faulting earthquakes volcanoes mountain building
all of these are correct
Where is the youngest ocean floor found?
along the crest of mid-ocean ridges
Continued movement of the continental crust on the west side of the San Andreas fault could result in which of the following features?
an island
The East African rift is a divergent plate boundary that is splitting the continent of Africa into two pieces. What will eventually form around this divergent boundary?
an ocean
australia is composed of
continental crust
In general, where do earthquakes AND volcanic eruptions occur?
convergent plate boundaries divergent plate boundaries
Plates move apart at __________ boundaries, move together at __________ boundaries, and move side-by-side at __________ boundaries.
divergent/convergent/transform
earthquakes occur in south california generally occur above a
fault
A very long-lived magma source located deep in the mantle is called a ________.
hot spot
old faitful geyser gets its energy from
hot spot
The continental drift hypothesis was rejected primarily because Alfred Wegener could not ________
identify a mechanism capable of moving continents
Which geologic features are associated with divergent boundaries?
mid-ocean ridges and continental rift valleys
Complete this statement: Divergence is to moving away as convergence is to _______.
moving toward
What forms at divergent plate boundaries?
new oceanic lithosphere
Linear, magnetic patterns associated with mid-ocean ridges are configured as ________.
normal and reversed magnetized strips roughly parallel to the ridge
The ________ is an example of an active, continent-continent collision.
northward movement of India into Eurasia
Which geologic features are associated with convergent boundaries?
ocean trenches and volcanoes
In general, where do volcanoes form in subduction zones?
on the overriding plate, away form the convergent boundary
The occurrence of stream channels that have been offset along a transform fault are indicative of which of the following conditions?
opposite sides of the fault have shifted horizontally
_______ _________ found in the atlantic ocean between NA and EU is composed of dense and relatviely young rock
seafloor crust
slowly increasing distance between south america is due to
seafloor spreading
layered____________ exposed by erosion at the grand canyon is
sedimentary rock
What type of stress is most directly associated with transform faults?
shear stress
extremely deep marianas trench is result of
subduction
Deep-focus earthquakes, those between 300 and 700 kilometers below the surface, occur only in association with ________.
subduction zones
Which of the following lithospheric plates is not included among the seven largest?
the Philippine plate
Earth's lithospheric plates are composed of crust and which of the following layers?
the outermost portion of the mantle
Which of the following paleoclimatic evidence supports the idea of the late Paleozoic super continent in the Southern Hemisphere?
tillites (rocks formed by glaciers) in South Africa and South America
Which of the following geologic processes and/or phenomena is not found at transform plate boundaries?
volcanoes
Movement of plates away from each other at divergent boundaries typically shows which of the following average velocities?
5 cm per year
