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Geologic Time Scale
A geologic time scale
Time subdivisions and geologic ages in millions of years (Ma) are after the Geological Society of America 1999 Geologic Time Scale.

Click here to learn about the geologic history of the Big Bend region.
Click here for a list of selected references (reports and maps) for the Big Bend region.
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U.S. Department of the Interior - U.S. Geological Survey
The URL of this page is: http://3dparks.wr.usgs.gov/bigbend/html/timescale.htm
Maintained by Webmaster, Menlo Park, CA
Last modified: 4/21/2005

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