| Abstract: | Introduction
Effective communication in the geosciences requires consistent uses of stratigraphic nomenclature, especially divisions of geologic time. A geologic time scale is composed of standard stratigraphic divisions based on rock sequences and calibrated in years (Harland and others, 1982). Over the years, the development of new dating methods and refinement of previous ones have stimulated revisions to geologic time scales. Since the mid-1990s, geologists from the U.S. Geological Survey (USGS), State geological surveys, academia, and other organizations have sought a consistent time scale to be used in communicating ages of geologic units in the United States. Many international debates have occurred over names and boundaries of units, and various time scales have been used by the geoscience community. |
| Genre: | USGS Numbered Series |
| ProdID: | 79747 |
| Citation Author: | U.S. Geological Survey Geologic Names Committee |
| Citation Contributing Office: | Geological Survey (U.S.) |
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| Citation Language: | ENGLISH |
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| Citation Month: | Mar |
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| Citation Phsyical Description: | 2 p. |
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| Citation Publisher: | Geological Survey (U.S.) |
| Citation Series: | Fact Sheet |
| Citation Series Code: | FS |
| Citation Series Number: | 2007-3015 |
| Citation Search Results Text: | Divisions of Geologic Time - Major Chronostratigraphic and Geochronologic Units; 2007; FS; 2007-3015; U.S. Geological Survey Geologic Names Committee |
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| Citation Year: | 2007 |
| Type: | citation/reference |
| Text: | Divisions of Geologic Time - Major Chronostratigraphic and Geochronologic Units; 2007; FS; 2007-3015; U.S. Geological Survey Geologic Names Committee |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/fs_2007_3015.jpg |
| URL (INDEX PAGE): | http://pubs.usgs.gov/fs/2007/3015/ |
| Date Other: | Tue, 3 Apr 2007 00:00 -0500 |
| Publisher: | Geological Survey (U.S.) |
