Sullivan Siltstone Member of Bonneterre Formation (MO*)
latest Middle to earliest Late Cambrian (early Croixan; latest Lincolnian to earliest Millardan; latest Marjuman to earliest Steptoean)*
Type section (surface): Crooked Creek cryptoexplosive structure, in center E/2 NW/4 sec. 17, T. 36 N., R. 4 W., Crawford Co., MO, in the Ozark uplift (this is the only surface exposure of this unit). Named from town of Sullivan, Franklin Co., MO, which is located 38 mi north of type section, just north of the Franklin-Crawford Co. line (Kurtz and others, 1975).
Reference section (subsurface): depth-interval 1,495.0 to 1,533.0 ft, St. Joe Minerals Corp. No. 64W63 (WR-1) core, in SE/4 SE/4 sec. 16, T. 29 N., R. 13 W., Wright Co., MO (Kurtz and others, 1975; Thompson and others, 2013).
Ozark uplift*
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
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Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).