Wisconsin Arch
Location
Central Wisconsin, northern Illinois (fig. 1;
plate 1 inset)
References
Pirtle 1932, Bieber 1949, Willman and Templeton 1951, Green 1957, Heyl et al. 1959, Doyle 1965, Paull and Paull 1977, Kolata et al. 1978, Kolata et al. 1983
Description
The Wisconsin Arch is a broad, positive area that separates the Michigan Basin on the east from the Forest City Basin on the west. The northern end of the arch is termed the Wisconsin Dome and is a region of Precambrian outcrops in northern Wisconsin. The rest of the arch is overlapped by Cambrian, Ordovician, and Silurian sedimentary rocks. On the southeast the Wisconsin Arch connects with the Kankakee Arch, which runs between the Michigan and Illinois Basins.
The Wisconsin Arch apparently began to emerge late in the St. Croixan Epoch (Cambrian) and was well established by the middle of the Ordovician Period. It may have been covered by seas in late Ordovician through middle Silurian time, but rose again in late Silurian or Devonian time (Paull and Paull 1977).
Figure(s)
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