CAMBRIAN 8 ORDOVICIAhT 



Fig. 5.3. Cross section of the Michigan basin, after American Association of Petroleum Geolo- 

 gists, 1954, Geo/ogic Cross Section of Paleozoic Rocks, central Mississippi to northern Michigan. 

 The Cambrian is mostly a sandstone and shale sequence; the Black River through Traverse a 



limestone, dolomite, and evaporite sequence, the Antrim through Michigan a shale and sand- 

 stone sequence. 



