Earthquake activity folded the rock layers

Volcanic eruptions destroyed a rock layer

Erosion removed several layers of rock.

Weathering changed the layering of the rocks

Earthquake activity folded the rock layers

Volcanic eruptions destroyed a rock layer

erosion removed several layers of rock.

Weathering changed the layering of the rocks

Tectonic plates on the earth pushed together.

Tectonic plates on the earth pulled apart.

Tectonic plates on the earth slid past each other.

Tectonic plates on the earth broke into small pieces.

an earthquake

a mountain range

a river

a volcano

Ancient organisms were able to swim much farther than modern organisms.

The same organisms existed more than once in the history of Earth.

Modern land masses were once connected but moved apart.

The same environmental conditions once existed all over Earth.