The Earth formed about 4.5 billion years ago through the accretion of dust and gas in the solar nebula.

Pangea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras, about 250 million years ago.

Stromatolites are the oldest known fossils, dating back to about 3.5 billion years ago.

The Cretaceous-Paleogene extinction event, also known as the K-T extinction event, occurred about 66 million years ago and wiped out the dinosaurs.

Plate tectonics is the theory that explains how the Earth's continents have moved over time.

Seafloor spreading is the process by which new oceanic crust is formed.

Subduction is the process by which oceanic crust is recycled back into the mantle.

The crust is the layer of the Earth that is composed of solid rock.

The mantle is the layer of the Earth that is composed of molten rock.

The outer core is the layer of the Earth that is composed of liquid iron.

The inner core is the layer of the Earth that is composed of solid iron.

Erosion is the process by which the Earth's surface is eroded by wind, water, and ice.

Deposition is the process by which eroded material is deposited in a new location.

Sedimentation is the process by which sediment is compacted and cemented together to form rock.

Weathering is the process by which rocks are broken down into smaller pieces.