USGS Visual Identifier
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Geologic Unit: Juniata

Usage:
Juniata Formation (WV*,VA*,TN*,PA*,MD*)
Juniata Formation of Judy Gap Group (WV)

Age:
Ordovician, Late*
Maysvillian*
Richmondian*


Geologic Province:
Appalachian basin*




Areal Extent:
MD*
PA*
TN*
WV*
VA*

Type Locality:
Occurrence on Juniata River, south-central PA (Clark, 1897).

Subunits:
East Waterford (PA), Plummer Hollow (PA), and Run Gap (PA) Members

Unit Name History:
Named (Darton, 1896). Overview (Clark, 1897). Age modified (Stose, 1909). Assigned Bald Eagle as basal member (Willard and Cleaves, 1939). Extended into TN (Rodgers, 1953). Revised, subdivided (Swartz, 1957). Overview, members used (Thompson, 1970). Overview (Young and Rader, 1974). Revised to part of Judy Gap Group (Chen, 1977). Overview (Berg and others, 1980). Overview in PA, informal members (Faill and others, 1989). Extended into WV subsurface (Ryder, 1992). Overview (Driese and Foreman, 1992; Retallack, 1993).

Note: If you need more information, please contact Nancy Stamm (nstamm@usgs.gov).
Asterisks (*) indicate usage by the U.S. Geological Survey. Other usages by state geological surveys.

"No current usage" implies that a name has been abandoned or that it has fallen into disuse. Former usage and, if known, replacement name given in parentheses ().

Slashes (/) indicate unit name usage violates the 1983 North American Stratigraphic Code. This violation may be explained within brackets ([ ]).






U.S. Department of the Interior, U.S. Geological Survey, Reston, VA, USA
URL http://ngmdb.usgs.gov/ngmdb/ngm_catalog.ora.html
Database project personnel
Last modified: 15-Jan-2013