Geology Midterm (Chapter 4)

A mid-ocean ridge

is marked by a series of submarine volcanoes

According to current plate tectonics theory,

plates are composed of the crust and the uppermost part of the mantle

According to the mantle plume model, hot-spot plumes

partially melt the base of the overlying lithosphere, and the magma that is formed rises toward the surface

Accretionary prisms form due to what process

Subduction

Asthenosphere

is warm enough to flow slowly

Continental mountain ranges such as the Alps and Appalachians are the result of which of the following

Collision

Continents

passively ride along as the sea floor spreads

Earthquakes but not volcanoes occur in San Francisco because

two plates are moving past each other there

Plates shift the continents

around as they move, so Earth's surface is constantly changing.

The direction of movement of the Pacific Plate

changed about 47 million years ago, which created a bend in the Hawaiian-Emperor hot-spot track

Oceanic lithosphere

that is 10 million years old is cool enough to be denser than the asthenosphere, so it can sink down through the asthenosphere

Of the choices below, select the one that accurately pairs the feature with the type of plate boundary at which it occurs

Trenches occur at subduction zones

Plate movement is influenced by each of the following EXCEPT

mantle plumes, which are created when hot rock rises up from the deep mantle and creates melting at the base of the lithosphere

Sometimes more than two plates come together at a special kind of plate boundary, as shown in the figure. What type of plate boundary is shown here at the intersection between the African, Indian, and Antarctic plates

Triple junction

The Himalayas are growing because

a continental plate is colliding with another continental plate there

The center of a mid-ocean ridge is where

new oceanic lithosphere is being created

The chain of Hawaiian Islands extends northwest across the Pacific as shown in the figure

a hot spot currently sitting under Hawaii and the Pacific Plate moving across it in a northwesterly direction

The figure shown here is a typical example of what plate boundary?

convergent

The global occurrence of earthquakes reveals that

they usually occur on the boundaries of plates or at hot spots

What about lithosphere and asthenosphere is true?

Lithosphere consists of the crust and the upper mantle, and behaves like a hard layer that breaks and bends