Silurian-aged bedrock in eastern Wisconsin is shallow, fractured, and contains groundwater that is susceptible to surface water contamination. Revisions to Wisconsin state rules ATCP50 and NR151 to regulate manure spreading over this Silurian-aged bedrock create …
Lafayette County
Bedrock Geology of Lafayette County, Wisconsin
Located primarily in the Driftless Area of southwest Wisconsin, Lafayette County is underlain by Paleozoic-aged bedrock, primarily siliciclastic and carbonate sedimentary units. These sedimentary rocks were mildly deformed during the Paleozoic, with fold amplitudes and …
Anglesite
Formula: PbSO4 Orthorhombic Description: Close-up of pale yellow anglesite crystals on galena. Largest crystal is about 2 mm across. Bear Hole Mine, Shullsburg, Lafayette County, Wisconsin. (Image courtesy of Tom Loomis, Dakota Matrix Minerals, Rapid City, South Dakota.) Anglesite is a …
Ankerite
Formula: Ca(Fe,Mg,Mn)(CO3)2 Hexagonal Description: Ankerite is formed as a sedimentary precipitate, a groundwater and hydrothermal precipitate and by metamorphic recrystallization of iron-rich sedimentary rocks. ASHLAND COUNTY: Ankerite is a component of the Ironwood iron formation in the Penokean …
Apatite Group
Formula: Ca5(PO4)3(F,Cl,OH) Hexagonal Description:Apatite denotes a family of minerals referred to variously in older literature as “fluorapatite,” “chlorapatite,” “carbonate-apatite” or “hydroxlyapatite” and in newer literature as apatite- (CaF) etc. depending on which anion group dominates. Members …
Aragonite
Formula: CaCO3 Orthorhombic Description: Aragonite forms in low temperature hydrothermal deposits, especially as sinter around hot springs and amygdules in basalts. It also occurs as speleothems, as organic or inorganic precipitates in marine sediments. Finally, it forms …
Aurichalcite
Formula: (Zn,Cu)5(CO3)2(OH)6 Monoclinic Description: Aurichalcite with pen for scale. From the mineral collection of Brigham Young University Department of Geology, Provo, Utah, Mineral Specimens 082. Courtesy of the U.S. Geological Survey Denver Library Photographic Collection. (Photo by Andrew …
Azurite
Formula: Cu3(CO3)2(OH)2 Monoclinic Description: Azurite is an attractive blue mineral found as a secondary weathering and supergene mineral formed from the alteration of native copper and other copper minerals. It is often found associated with and altering …
Baryte
Formula: BaSO4 Orthorhombic Description:Baryte is found general in low temperature hydrothermal deposits. It is most common in Wisconsin in the Upper Mississippi Valley zinc-lead district in Grant, Iowa, and Lafayette Counties where it is associated with …
Bornite
Formula: Cu5FeS4 Orthorhombic Description: Bornite forms as a primary hydrothermal precipitate or a later supergene replacement mineral. It occurs with other copper minerals such as covellite, malachite and azurite. It is marked by its intense purple to …