- Usage in publication:
-
- Dreibelbis Member*
- Modifications:
-
- Named
- Dominant lithology:
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- Graywacke
- Sandstone
- AAPG geologic province:
-
- Appalachian basin
Summary:
Rocks mapped as the Martinsburg Formation by Willard (1943) are here named the Dreibelbis Member of the Windsor Township Formation in the Greenwich slice of the Hamburg klippe in PA. The member contains three main intercalated rock types which may be lens-shaped bodies: 1) laminated to thick-bedded calcareous graywacke interbedded with graywacke, siltstone, and mudstone; 2) ripple laminated, locally conglomeratic, calcareous graywacke sandstone interbedded with siltstone and mudstone; 3) medium- to thick-bedded locally calcareous sandstone interbedded with siltstone, mudstone, and claystone-shale. Apparent thickness is 3,660 m. Age is Middle Ordovician based on graptolites.
Source: GNU records (USGS DDS-6; Reston GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).