Hook Member of Macy Limestone of Plattin Group (MO)
Late Ordovician (Mohawkian)
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)]
Ozark uplift
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
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