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National Geologic Map Database

Geologic Unit: Chainman

Usage:

Chainman Shale (CA*,NV*,UT*)
Chainman Formation (NV*)


Subunits:

(descending): Delle Phosphatic Member (NV*,UT*), Jensen Member (UT), Needle Siltstone Member (UT*), Scotty Wash Member (NV), Skunk Spring Limestone Bed (UT*), Willow Gap Member (UT).


Geologic age:

Mississippian, Early*
Osagean*
Mississippian, Late*
Meramecian*
Chesterian*


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

Named from the Chainman Mine, near Lane, Ely quadrangle, White Pine Co., eastern NV (Spencer, 1917).
Type section: Robinson Canyon, 2 mi west of Ely, Egan Range, [Ely quadrangle, White Pine Co., eastern NV] (GNC index card files).


AAPG geologic province:

Great Basin province*


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 ([ ]).