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National Geologic Map Database

Geologic Unit: Hook

Usage:

Hook Member of Macy Limestone of Plattin Group (MO)


Geologic age:

Late Ordovician (Mohawkian)


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

Type section (same as Macy Limestone): roadcut on U.S. Highway 61 [MO Highway 25], in SE/4 NE/4 SE/4 sec. 28, T. 38 N., R. 8 E., Ste. Genevieve Co., Weingarten 7.5-min quadrangle, southeastern MO (Larson, 1951). [From T.L. Thompson (1991) and US geologic names lexicon, USGS Bull. 1200]
Reference sections: (1) well exposed on U.S. Interstate Highway I-55 in roadcuts beginning 0.5 mi north of the bridge over Joachim Creek and extending to the intersection with Jefferson County Road M at Barnhart, Herculaneum 7.5-min quadrangle; (2) in a roadcut on the north frontage road to U.S. Interstate Highway I-44 west of the Allenton-Six Flags exit, western St. Louis Co., Eureka 7.5-min quadrangle; (3) in roadcut on MO Highway 30 at Weber Hill, in NE/4 sec. 27, T. 43 N., R. 4 E., Jefferson Co., House Springs 7.5-min quadrangle. [From T.L. Thompson (1991)]


AAPG geologic province:

Ozark uplift


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 ([ ]).