Named the Llewellyn Formation for Llewellyn, Schuylkill Co., eastern PA. Consists of gray- and brown-hued beds of conglomeratic sandstone, quartzose sandstone, subgraywacke, and siltstone with lesser amounts of conglomerate, shale, and anthracite. Maximum thickness is 3500 feet. Base of unit is placed below the shale bed that underlies the Buck Mountain coal bed. Overlies the Pottsville. The Llewellyn is of Late Pennsylvanian age.
Source: GNU records (USGS DDS-6; Reston GNULEX).
The age of the Llewellyn Formation is shown on geologic map as Middle and Late Pennsylvanian.
Source: GNU records (USGS DDS-6; Reston GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
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