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National Geologic Map Database

Geologic Unit: Lance

Usage:

Lance Formation (CO*,MT*,WY*)
Called Ceratops beds and Lance Creek Beds in early reports.


Subunits:

(alphabetical): Black Buttes coal group (informal) (WY), Ilo Ridge Member (WY), Red Rim Member (CO*,WY*), Torrington Member (WY).


Geologic age:

Late Cretaceous (Maastrichtian)*; locally early Tertiary (Paleocene)*


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

Type locality: Lance Creek area, north-central part Niobrara Co. (formerly a part of Converse Co.), WY; mouth of Lance Creek is in sec. 11, T. 39 N., R. 62 W., [Lance Creek 30- x 60-min quadrangle] (US geologic names lexicons, USGS Bull. 896, 1200).


AAPG geologic province:

Bighorn basin*
Central Montana uplift*
Green River basin*
Powder River basin*
Sioux uplift*
Williston basin*
Wind River 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 ([ ]).