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National Geologic Map Database

Geologic Unit: Guernsey

Usage:

Guernsey Formation (WY*-recognized locally in Hartville uplift)


Geologic age:

Early Mississippian (Tournaisian; Kinderhookian to Osagean)*


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

[Mapped around town of Guernsey, Hartville uplift, Hartville quadrangle (scale 1:125,000), Platte Co., southeastern WY (see Smith, 1903).]
Type section considered to be Hartville Canyon section on south-facing nose immediately east of North Platte River below Guernsey Reservoir, in S/2 NE/4 sec. 27, T. 27 N., R. 66 W., [Guernsey Reservoir 7.5-min quadrangle], Platte Co., eastern WY. It is in vicinity of Smith's (1903, p. 2) measured section of the Guersney Formation, near town of Fairbank [no longer exists], which shows the general character of the beds composing the formation (Sando and Sandberg, 1987).


AAPG geologic province:

Denver basin*


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