Plummer Hollow (new name) assigned as middle member of Juniata formation. Consists of red silty mudstone with interbeds of red siltstone and sandstone. Overlies East Waterford red sandstone and shale member (new) and underlies Run Gap red sandstone member. Thins eastward, and, at Waggoners Gap, beds lithologically referable to Plummer Hollow are not present and instead are about 360 ft of red sandstones of type that forms East Waterford member.

Source: GNU records (USGS DDS-6; Reston GNULEX).

Subdivision of the Juniata Formation into three members in central PA is based largely on differences in the relative proportion of sandstone and mudrock. In the lowest East Waterford Member (lithofacies D of this report) red sandstones dominate over dark red mudrocks, and the sandstones are organized into beds that are medium to thick, cross-laminated, and laterally extensive and sheet-like. The middle Plummer Hollow Member (lithofacies E) contains more mudrock than sandstone, and the sandstone and mudrock are more or less regularly interbedded, in some places as fining-upward sequences. Abundant SKOLITHOS-like burrows filled with red mudstone occur in the sandstone. The upper Run Gap Member (lithofacies F) is largely red lithic wacke and underlies quartz arenite at the base of the Tuscarora Formation. Age is Ashgillian.

Source: GNU records (USGS DDS-6; Reston GNULEX).