Steven Dutch, Professor Emeritus, Natural and Applied Sciences, University of Wisconsin - Green Bay
The Cambrian consists of numerous thick sandstone units, many very mature. In the Green Bay area it is the most important deep aquifer. Note how the main Cambrian-Precambrian contact defines the Wisconsin Arch. Numerous Precambrian outliers poke through the Cambrian rocks; there would doubtless be many more if the rocks were better exposed.
Created 11 Sep 1997, Last Update 11 January 2020