The study of strata is called stratigraphy, and using a few basic principles, it is possible to work out the relative ages of rocks. In the Grand Canyon, the layers of strata are nearly horizontal.

The basin contains a sedimentary rock record of up to 5 km (16,000 ft) of strata that were deposited over 240 million ... exhibit will focus on generating a holistic understanding of its stratigraphy ...

and Talkeetna Mountains Physical sedimentology and stratigraphy of sedimentary strata in Alaska, Arizona, and Pennsylvania, including recent studies on fossil eurypterid-bearing Silurian carbonates in ...

This work has focused on a range of petroleum geology, sedimentology, ichnology, and stratigraphy questions related to understanding shallow-marine sedimentary strata. Dr. James MacEachern's past ...