Science Ch. 6 Study Guide

Front 1

Where do volcanic belts form?

Back 1

Along the boundries of Earth's plates.

Front 2

Where does a volcano form?

Back 2

above a hotspot when magma erupts when magma erupts throught the crust and reaches the surface.

Front 3

volcano

Back 3

a weak spot in the crust where magma has come to the surface

Front 4

magma

Back 4

a molten mixture or rock-forming substances, gases, and water from the mantle

Front 5

lava

Back 5

magma when it reaches the surface

Front 6

Ring of Fire

Back 6

the volcano belt that rims the Pacific Ocean

Front 7

island arc

Back 7

a string of islands formed by volcanoes along a deep-ocean trench

Front 8

hot spot

Back 8

an area where magma from deep within the mantle melts through the crust above it

Front 9

how does a volcano errupt?

Back 9

the force of the expanding gasses pushes pushes magma from the magma chamber through the pipe until it flows or explodes out the vent

Front 10

What are the two ways geologists classify volcanic eruptions?

Back 10

quiet and expolsive

Front 11

Active volcano

Back 11

is likely to erupt again, has erupted in the past 10,000 years

Front 12

Dormant volcano

Back 12

volcano is not erupting, but likely to start again

Front 13

Extinct volcano

Back 13

volcano that is not expected to erupt again

Front 14

Magma chamber

Back 14

The pocket beneath a volcano where magma collects

Front 15

pipe

Back 15

a long tube through which magma moves from the magma chamber to Earth's surface

Front 16

vent

Back 16

opening through which magma leaves the volcano

Front 17

lava flow

Back 17

area covered by lava from a volcano's vent

Front 18

crater

Back 18

a bowl-shaped area that forms around a volcano's central opening

Front 19

silica

Back 19

a material found in magma that is formed from the elements of oxegyn and silicon (large amounts could cause expolisive eruptions)

Front 20

pyroclastic flow

Back 20

an expolosive volcanic eruption of ash, cinders, bombs, and gases

Front 21

geyser

Back 21

a fountain of water and steam that builds up pressure underground and erupts at regular intervals

Front 22

What are the features formed my magma?

Back 22

volcanic necks, dikes, sills, and batholiths

Front 23

Shield volcano

Back 23

a wide gently sloping mountain made of layers of lava; formed by quiet eruptions

Front 24

cinder cone

Back 24

a steep cone-shaped hill or small ountain made of volcanic ash, cinders, and bombs

Front 25

composite volcano

Back 25

A tall, cone-shaped mountain in which layers of lava and ash alternate

Front 26

caldera

Back 26

the large whole at the top of a volcano formed when the roof of a magma chamber collapses

Front 27

volcanic neck

Back 27

Hardened magma in a volcano's pipe

Front 28

dike

Back 28

a slab of volcanic rock formed when magma forces itself across rock layers (vertically)

Front 29

sill

Back 29

a slab of volcanic rock formed when magma squeezes between rock layers (horizontally)

Front 30

intrusion

Back 30

an igneous rock layer formed when magma hardens beneath Earth's crust

Front 31

batholith

Back 31

a mass of rock formed when a large body of magma cools inside the crust

Front 32

What geological features did the movements of the Pacific and North American plates produce

Back 32

faults, volcanoes, mountain ranges, and basins

Front 33

basins

Back 33

a broad, bowl-shaped valley formed where the crust is bent downward

Front 34

Central Valley

Back 34

the large basin in California between the Coast Ranges and the Sierra Nevada