Methods of dating meteorites
Over the years, the development of new dating methods and the refinement of previous methods have stimulated revisions to geologic time scales.
Advances in stratigraphy and geochronology require that any time scale be periodically updated. Geological Survey (USGS), State geological surveys, academia, and other organizations have sought to create a consistent time scale to be used in communicating ages of geologic units in the United States.
Geologic Time Scale: Divisions of Geologic Time approved by the U. It reflects ratified unit names and boundary estimates from the International Commission on Stratigraphy (Ogg, 2009). * Changes to the time scale since March 2007 (see text). URL: Effective communication in the geosciences requires consistent uses of stratigraphic nomenclature, especially divisions of geologic time. By 1788 Hutton had formulated a theory of cyclic deposition and uplift, with the earth indefinitely old, showing “no vestige of a beginning—no prospect of an end.” Hutton considered the present to be the key to the past, with geologic processes driven by the same forces as those we can see at work today.