Usage:
Chocolay Group of Marquette Range Supergroup (recognized locally in MI*,WI*)
Notable exposures in Marquette Range, Menominee Range, Gogebic iron range, and Iron River-Crystal Falls district, Northern Peninsula.
Subunits:
(alphabetical): Bad River Dolomite (MI*,WI*), Enchantment Lake Formation (MI*), Fern Creek Formation (MI*), Kona Dolomite (MI*), Mesnard Quartzite (MI*), Randville Dolomite (MI*), Saunders Formation (MI*,WI*), Sturgeon Quartzite (MI*), Sunday Quartzite (MI*,WI*), Wewe Slate.
Geologic age:
Paleoproterozoic*
Type section, locality, area and/or origin of name:
Named from Mount Chocolay [not shown on modern topographic map] and Chocolay Junction on the Duluth, South Shore, and Atlantic RR, 3 mi southeast of Marquette, close to southeast corner of Marquette 7.5-min quadrangle, eastern Marquette Co., Northern Peninsula, northwestern MI (James, 1958; Gair and Thaden, 1968).
AAPG geologic province:
Lake Superior region*
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 ([ ]).