Chapter 10. Continental Drift

Front 1

Continental Drift

Back 1

The hypothesis that a single large landmass broke up into smaller landmass broke up into smaller landmasses to form the continents, which then drifted to their present locations.

Front 2

Mid-Ocean ridge

Back 2

A long, undersea mountain chain that has a steep, narrow valley at its center, that forms as magma rises from the asthenosphere, and that creates new oceanic lithosphere (sea floor) as tectonic plates move apart.

Front 3

Sea-Floor spreading

Back 3

The process by which new oceanic lithosphere (sea floor) forms when magma rises to Earth's surface at mid-ocean ridges and solidifies, as older, existing sea floor moves away from the ridge.

Front 4

Paleomagnetism

Back 4

The study of the alignment of magnetic minerals in rock, specifically as it relates to the reversal of Earth's magnetic poles; also the magnetic properties that rock acquires during formation.

Front 5

Plate tectonics

Back 5

The theory that explains how large pieces of the lithosphere, called plates, move and change shape.

Front 6

Lithosphere

Back 6

The solid, outer layer of Earth that consists of the crust and the rigid upper part of the mantle.

Front 7

Asthenosphere

Back 7

The solid, plastic layer of the mantle beneath the lithosphere.

Front 8

Divergent boundary

Back 8

The boundary between tectonic plates that are moving away from each other.

Front 9

Convergent boundary

Back 9

The boundary between tectonic plates that are colliding.

Front 10

Transform boundary

Back 10

The boundary between tectonic plates that are sliding past each other horizontally.

Front 11

Rifting

Back 11

The process by which Earth's crust breaks apart; can occur within continental crust or oceanic crust.

Front 12

Terrane

Back 12

A piece of lithosphere that has a unique geologic a history and that may be part of a larger piece of lithosphere, such as a continent.

Front 13

Supercontinent cycle

Back 13

The process by which supercontinents form and break apart over millions of years.

Front 14

Pangaea

Back 14

The supercontinent that formed 300 million years ago that began to break up 200 million years ago.

Front 15

Panthalassa

Back 15

The single, large ocean that covered Earth's surface during the time the supercontinent Pangaea existed.