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National Geologic Map Database

Geologic Unit: Flour Sack

Usage:

Flour Sack Member of Bright Angel Shale of Tonto Group (AZ*-local)
Recognized locally in western Grand Canyon.


Geologic age:

Middle Cambrian*


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

Not designated. Named from former rapids of that name 8 mi east of Grand Wash Cliffs, western Grand Canyon [Mohave Co., northwestern AZ] (McKee, 1945).


AAPG geologic province:

Plateau sedimentary province*


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 ([ ]).