Bronson Group (IAPAb;0)

Bronson Group

Interval includes Pleasanton, Hertha, Elm Branch, Swope, Galesburg, Dennis formations. Primary Lithologies: limestone, fossiliferous; shale/mudstone, light to dark gray. Secondary lithologies: mudstone to siltstone, gray to green-gray; limestone, coated grain. Minor: black shale, phosphatic; red/maroon mudstone; coal; chert. Maximum thicknesses 100-130 ft (30-40 m).

State	Iowa
Name	Bronson Group
Geologic age	Middle to Upper Pennsylvanian, uppermost Desmoinesian-lower Missourian
Lithologic constituents	Major Sedimentary > Carbonate > Limestone (Bed)fossiliferous; minor coated grain Sedimentary > Clastic > Mudstone > Shale (Bed)shale/mudstone, light to dark gray; incidental red/maroon Minor Sedimentary > Clastic > Mixed-clastic > Siltstone-mudstone (Bed)mudstone to siltstone, gray to green-gray Incidental Sedimentary > Chemical > Chert (Bed) Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed)phosphatic Sedimentary > Coal (Bed)
References	Witzke, Brian J., Anderson, Raymond R., and Pope, John P., 2010, Iowa Geological and Water Survey, DNR, Bedrock Geologic Map of Iowa, OFM-2010-1. Scale 1:500,000.
NGMDB product	NGMDB product page for 96753
Counties	Adair - Appanoose - Audubon - Cass - Clarke - Dallas - Decatur - Guthrie - Harrison - Madison - Mills - Pottawattamie - Ringgold - Shelby - Union - Wayne

Bronson Group

Witzke, Brian J., Anderson, Raymond R., and Pope, John P., 2010, Iowa Geological and Water Survey, DNR, Bedrock Geologic Map of Iowa, OFM-2010-1. Scale 1:500,000.