Understand the history of the Earth through geologic time.

This is a nice explanation of geologic time and Earth's major eras. Although this site is designed for younger students, it is mostly text with few images.

This video reviews over geologic time scale and methods to teach this appropriately in the classroom. [9:15]

The Black Hills Institute of Geological Research is a world-renowned center for paleontology. Here they describe in clear language how fossils are formed and preserved, and what information they give us about the past, particularly in...

For this investigation, students start exploring the U.S. Geological Survey's (USGS) online version of the geologic map of Texas. The geologic time scale shown will help them figure out how old the rocks are in various parts of Texas.

Students learn about fossils - what they are, how they are formed, and why scientists and engineers care about them.