Usage:
Equality Formation of Mason Group (IL*)
Equality Formation (IN,MI*,WI)
Subunits:
(alphabetical) --all in IL: Carmi Member; Cottage member (informal); Texas City member (informal).
Geologic age:
Pleistocene (Wisconsinan Age)*
Type section, locality, area and/or origin of name:
Type section [no longer exposed, ca. 1996]: Saline River section, excavation at bridge crossing Saline River, 4 mi (6.4 km) southwest of Equality, in southeast corner of SW/4 sec. 27, T. 9 S., R. 7 E., Gallatin Co., southeastern IL. Named from village of Equality, Gallatin Co., southeastern IL (Willman and Frye, 1970; see Hansel and Johnson, 1996).
Principal reference sections (Hansel and Johnson, 1996):
(1) Charleston section, in south wall of Charleston stone quarry, approx. 500 ft (152 m) west of Embarrass River and 100 ft (30 m) north of RR tracks, in SW/4 NW/4 sec. 5, T. 12 N., R. 10 E., Ashmore 7.5-min quadrangle, Coles Co., east-central IL;
(2) Core 9V, Lake Michigan, Lat. 42 deg. 23.8 min. N., Long. 87 deg. 33.2 min. W., about 12.5 mi (20 km) east of Waukegan, IL;
(3) Wedron section, in highwalls of pits in Wedron Silica Company quarries, in secs. 8, 9, 10, and 16, T. 34 N., R. 4 E., Wedron 7.5-min quadrangle, La Salle Co., IL.
AAPG geologic province:
Illinois basin*
Michigan basin*
Wisconsin arch*
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 conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).