Reston, VA – The U.S. Geological Survey (USGS) and the Association of American State Geologists (AASG) announced that they have developed an updated geologic time scale and color scheme for use in ...

What are some events that all of us have had in our lives? Ask the class "What are some events that all of us have had in our lives?" Make a list of 5 or 6 things on the board. Let’s organize these!

Introduction / F.M. Gradstein -- Chronostratigraphy : linking time and rock / F.M. Gradstein, J.G. Ogg and A.G. Smith -- Biostratigraphy : time scales from graphic ...

Introduction -- Planetary time scale / Kenneth L. Tanaka and William K. Hartmann -- Precambrian / Martin J. Van Kranendonk, James Gehling, and Graham Shields -- Cambrian period / Shanchi Peng and ...

Much of our understanding of Earth's past is derived from stratigraphic records exposed in rock outcrops or recovered from ...

Every half-million years or so, for unknown reasons, the earth’s magnetic field suddenly flips. Within a period of 10,000 years—a mere instant on the geological time scale—the north and south magnetic ...