Plate tectonics

Dark rock with a fine texture.

Upper most mantle and crust together form this ridge layer about 100 km thick.

A dense ball of solid metal due to extreme pressure squeezing iron and nickel atoms.

A well-tested concept that explains a wide range of observations.

A layer of molten metal that surrounds the inner core.

Energy waves released by an earthquake that travel through the Earth.

A 50,000 km system of ridges that wind beneath Earth's oceans.

The place where two plates move apart.

Deep underwater canyons

Results from a force or weight such as rock pressing on an area

Typically light colored rock with a coarse texture.

The process where ocean floor sinks beneath a deep-ocean trench back into the mantle.

Any trace of an ancient organism that has been preserved in rock.

Cracks in the continents in the lithosphere broken into separate sections.

Device bounces sound waves off underwater objects and records their echoes.

A layer of hot solid rock about 3,000 km thick.

The idea that continents moved slowly over Earth's surface.

A process by which the sea floor spreads apart along both sides of the mid-Atlantic ridge.

The continents drifted together to form this super continent according to Wegener.

Breaks in Earth's crust where rocks have slipped past each other.

The place where two plates come together.

Theory by which pieces of Earth's lithosphere are in slow, constant motion driven by convection currents in the mantle.

The layer of rock that forms Earth's outer skin.

Hotter less ridge rock soften by the sun, like tar, just below the lithosphere.