Geologic units in Juneau county, Wisconsin

Additional scientific data in this geographic area

Cambrian, undivided (Cambrian) at surface, covers 99 % of this area

Sandstone with some dolomite and shale, undivided; includes Trempealeau, Tunnel City, and Elk Mound Formations

Gneiss, migmatite, and amphibolite (Late Archean) at surface, covers 0.5 % of this area

Quartzofeldspathic gneiss and less abundant amphibolite and migmatite. Includes granitoid rocks. Granitic gneiss at Port Edwards, WI on Wisconsin River has a U-Pb zircon age of 2870 +/- 13 Ma, and gneiss at Jim Falls in Chippewa River valley has a U-Pb zircon age of 2522 +/- 22 Ma (Sims and others, 1989)

Prairie du Chien Group (Ordovician) at surface, covers 0.3 % of this area

Dolomite with some sandstone and shale; includes Shakopee and Oneota Formations