State | Iowa |
---|---|
Name | Douglas Group |
Geologic age | Upper Pennsylvanian, upper Missourian-lower Virgilian |
Lithologic constituents |
Major
Sedimentary > Clastic > Mudstone (Bed, Calcareous, Carbonaceous)light to dark gray, part silt laminated; minor pedogenic mudstone, part red-brown, part calcareous/nodular; incidental carbonaceous shale
Sedimentary > Clastic > Mudstone > Shale (Bed)light to dark gray, part silt laminated
Minor
Sedimentary > Clastic > Siltstone (Bed)siltstone to very fine sandstone
Sedimentary > Carbonate > Limestone (Bed)fossiliferous, part coated grain
Incidental
Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed)
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 | |
Counties | Adair - Adams - Cass - Fremont - Madison - Mills - Montgomery - Pottawattamie - Ringgold - Taylor - Union |