Chapter 6 Volcanoes Flashcard

Front

What factors determine whether a volcanic eruption will be violent or relatively quiet?

Back

The amount of dissolved gases in the magma and the temperature of the magma.

Front

How are intrusive igneous bodies classified?

Back

They are classified by size and shape.

Front

What type of landform develops at plate boundaries where one oceanic plate descends beneath another?

Back

Volcanic Island Arc.

Front

What is a lens-shaped intrusive igneous mass close to Earth’s surface called?

Back

Laccolith.

Front

What type of lava flow resembles twisted braids in ropes as it cools and hardens?

Back

Pahoehoe.

Front

What is the primary cause of volcanic eruptions?

Back

The movement of magma from beneath the Earth's crust to the surface.

Front

What is the difference between intrusive and extrusive igneous rocks?

Back

Intrusive rocks form from magma that cools slowly beneath the Earth's surface, while extrusive rocks form from lava that cools quickly on the surface.

Front

What is a volcanic island arc?

Back

A chain of volcanic islands formed at a convergent plate boundary where one oceanic plate subducts beneath another.

Front

What is a dike in geology?

Back

A dike is a vertical or steeply inclined sheet of igneous rock that cuts across existing rock layers.

Front

What is the significance of the amount of dissolved gases in magma?

Back

The amount of dissolved gases affects the explosiveness of a volcanic eruption.