Photograph of Devonian sedimentary rock layers.

Quick Guides to Earth Science

Find quick introductions here to Earth science topics.

Last updated May 5, 2022.

Image above: Devonian-aged strata in New York State.

The Geologic Time Scale

Image showing the geologic time scale, including a pie chart that depicts the relative proportions of time represented by each geologic eon.

Introduction to Rocks

Photograph of rocks in Hawaii, including pieces of black basalt and white limestone made by corals.

Introduction to Plate Tectonics

Quick Guide to Common Fossils

Introduction to Earth Hazards

Photograph showing damage resulting from the San Francisco Earthquake of 1906.

Introduction to Climate

Photograph of a lake in northern Wisconsin.