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