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GeoWhen Database
This project aims to reconcile the international stratigraphic standards with many of the regional and archaic naming schemes that appear in the literature. In the process, the most recent International Commission on Stratigraphy (ICS) time scale has been combined with information on the estimated placement and length of other stages in order to put approximate dates on all of the stratigraphic intervals recorded here and to reconcile all of the various geologic time scales into a single self-consistent whole. The data is presented as timelines with and without stages, an A-Z list of stage names, and as downloadable files. The downloadable files consist of text versions of the Geologic Timeline (no stage), Geologic Timeline (with stages), and the A-Z Stage List, plus four files containing documented matrix laboratory (MATLAB) source code, which can be run to generate any of the pages in this archive as well as providing a variety of other functions.
Intended for grade levels:
  • High (9-12)
  • College (13-14)
  • College (15-16)
  • Graduate / Professional
Type of resource:
  • Text:
    • Ref. material
  • Dataset:
    • Modeled
  • Geological Sciences:
    • Geologic time
Technical requirements:
No specific technical requirements, just a browser required
Cost / Copyright:
No cost
Copyright 2003-2004 GeoWhen Database
DLESE Catalog ID: DLESE-000-000-006-661
Educational standards:
  • National Science Education Standards (NSES):
    • 9-12:
      • Unifying concepts and processes:
        • Systems, order, and organization
      • D - Earth and space science:
        • Origin and evolution of the earth system
Resource contact / Creator / Publisher:
Author: Robert A. Rohde
University of California at Berkeley