Pg. 4 (table 1); App., p. A8-1 to A8-3. Oak Creek Formation. Occurs in the Lake Michigan Lobe in southeastern Wisconsin. Consists of fine-grained glacial till, lacustrine clay, silt, and sand, and glaciofluvial sand and gravel. Thickness up to 35 m. Three till units designated 2A, 2B, and 2C, were identified by Mickelson and others (Wisconsin Coast Mgmt., Off. State Planning and Energy Shore Erosion Study Tech. Rpt., 1977). Overlies the upper till member of New Berlin Formation (new); contact is sharp or unconformable. Underlies lacustrine deposits, the Kewaunee Formation (new), or occurs as surface drift. Age is Pleistocene (late Wisconsinan).
Type section: Oakwood Road South section, exposure in Lake Michigan bluffs between Oakwood Road and Elm Road, just north of Oak Creek Power Plant, in NE/4 NE/4 NE/4 sec. 36, T. 5 N., R. 22 E., and NW/4 sec. 31, T. 5 N., R. 23 E., [in vicinity of Lat. 42 deg. 51 min. 15 sec. N., Long. 87 deg. 50 min. 06 sec. W.], Racine North 7.5-min quadrangle, Milwaukee Co., southeastern WI (Mickelson and others, 1984; Syverson and others, 2011).
Named from city of Oak Creek, southeastern Milwaukee Co., southeastern WI; name credited to Allan F. Schneider (Mickelson and others, 1984).
Reference section: Sheridan Park section, a Lake Michigan bluff exposures at the north end of Sheridan Park, just south of St. Francis Power Plant [now residential properties], in SW/4 NW/4 and NW/4 SW/4 sec. 24, T. 6 N., R. 22 E., [in vicinity of Lat. 42 deg. 58 min. 00 sec. N., Long. 87 deg. 50 min. 54 sec. W.], South Milwaukee 7.5-min quadrangle, Milwaukee Co., southeastern WI.
[Additional locality information from Syverson and others, 2011, Wisconsin lexicon of Pleistocene units, Wisconsin Geol. Nat. Hist. Survey Tech. Rpt., no. 1; supplemented from USGS historical topographic map collection TopoView and Wisconsin Highways www.wisconsinhighways.org, accessed on June 9, 2018.]

Source: Publication; US geologic names lexicon (USGS Bull. 1565, p. 224).