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National Geologic Map Database

Geologic Unit: Mifflintown

Usage:

Mifflintown Formation (PA*,WV*,MD,VA)
Mifflintown Limestone (PA*)


Subunits:

Rochester Member (PA), McKenzie Member (PA), Rabble Run Member (PA)


Geologic age:

Silurian (Llandovery to Ludlow; Niagaran Provincial Age)


Type section, locality, area and/or origin of name:

Outcrops on west bank of Juniata River, near Mifflintown, Juniata Co., central PA (Lesley, 1878).
Type section (composite): 2 exposures near Mifflintown, Mifflintown quadrangle, Juniata Co., central PA; (1) along main line of Pennsylvania RR, 0.25 mi northwest of Mifflintown boundary, 2,900 ft south of Lat. 40 deg. 35 min. N., and 2,800 ft east of Long. 77 deg. 25 min. W., and (2) in roadcut on east side of U.S. Rte 22, 0.3 mi north of Mifflintown boundary, 2,000 ft south of Lat. 40 deg. 35 min. N., and 4,900 ft east of Long. 77 deg. 25 min. W. (Miller, 1961).


AAPG geologic province:

Appalachian basin


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).