Jacobsville Sandstone (MIYj;0)

State	Michigan
Name	Jacobsville Sandstone
Geologic age	Middle Proterozoic
Original map label	Yj
Primary rock type	sandstone
Secondary rock type	siltstone
Other rock types	conglomerate; shale
Lithologic constituents	Major Sedimentary > Clastic > Sandstone (Bed)Red, brown, and white quartzose sandstone, and minor siltstone, shale and conglomerate Minor Sedimentary > Clastic > ConglomerateRed, brown, and white quartzose sandstone, and minor siltstone, shale and conglomerate Sedimentary > Clastic > Mudstone > ShaleRed, brown, and white quartzose sandstone, and minor siltstone, shale and conglomerate Sedimentary > Clastic > SiltstoneRed, brown, and white quartzose sandstone, and minor siltstone, shale and conglomerate
Map references	Sims, P.K., 1992, Geologic map of Precambrian rocks, southern Lake Superior region, Wisconsin and northern Michigan: U.S. Geological Survey Miscellaneous Investigations Map I-2185, scale= 1:500,000 [http://pubs.er.usgs.gov/publication/i2185]
Unit references	Sims, P.K., 1992, Geologic map of Precambrian rocks, southern Lake Superior region, Wisconsin and northern Michigan: U.S. Geological Survey Miscellaneous Investigations Map I-2185, scale= 1:500,000 [http://pubs.er.usgs.gov/publication/i2185]
Geographic coverage	Alger - Baraga - Chippewa - Gogebic - Houghton - Keweenaw - Luce - Marquette - Ontonagon