Geography

Age of Earth

4.6 billion years old.

Erratic

A misfit boulder carried by a glacier and deposited kilometers away.

Pangaea

The supercontinent that included all lands.

Convection currents

Movements in the Earth’s mantle responsible for plate movement.

Inner core

The very dense solid layer of the Earth made mostly of iron and nickel.

Outer core

The liquid layer of the Earth made mostly of iron and nickel.

Mantle

The thick rocky layer of the Earth made of molten rock with slow-moving currents.

Crust (Lithosphere)

The thin solid outer layer of the Earth made mostly of rocks and minerals.

Hydrosphere

The layer of water that covers 2/3 of the Earth.

Precambrian Era

The earliest era, 4600 million years ago, characterized by microscopic single-celled organisms.