U.S. Geological Survey: Science for a Changing World - USGS visiaul identifier and link to main Web site at http://www.usgs.gov/

Chart showing divisions of geologic time. For a more detailed explanation, contact Stanley Schweinfurth at sschwein@usgs.gov

Figure 19. Chart showing divisions of geologic time (ages are approximate). Since the Mississippian Period, major coal deposits have formed some place in the world except during the most recent period (Quaternary); however, major peat deposits formed (and are still forming) during the Quaternary and it is possible that there may be Quaternary lignite deposits as well. Periods of major coal deposits in the U.S. are shaded.


U.S. Department of the Interior, U.S. Geological Survey
URL: https:// pubs.usgs.gov /circ/c1143/html/fig19.html
For more information, contact Stanley Schweinfurth
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