Named for Petersburg, Pike Co., southwestern IN. Includes strata from base of Petersburg coal to base of Millersburg coal. Consists of alternating sandstones and shales with persistent bed of limestone at top. Thickness is 80 ft. Underlain by Brazil formation; overlain by Millersburg formation. [Age is Pennsylvanian.]
Source: GNU records (USGS DDS-6; Reston GNULEX).
Springfield Coal Member of Petersburg Formation of Carbondale Group is split locally in Warrick and Gibson Cos., IN, by clastic rocks of Folsomville Member of Petersburg Formation.
Source: GNU records (USGS DDS-6; Reston GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
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