This page kindly sponsored by Bill Cordua
|Location is approximate, based on center of defined region.|
|Latitude & Longitude:||44° North , 90° West (est.)|
|Museums in region:|
Wisconsin has a diversity of mineral occurrences. Glaciers covered most of the state during the Pleistocene. The glacial drift contains a variety of jumbled materials, including drift copper, diamonds, flour gold, and, most notably, Lake Superior agates. Despite the glacial cover, many bedrock outcrops occur in the state. The bedrock structure is essentially a gentle arch cored by Precambrian rocks. Proterozoic carbonate rocks form the edge of the arch. Vugs in these rocks yield interesting crystallized minerals, such as millerite, fluorite, calcite and marcasite. In the southwestern portion of the state (Iowa, Lafayette and Grant counties) these rocks host classic Mississippi Valley-type lead-zinc deposits. The state mineral, galena, and state mascot, the badger, refer to the main ore and the nineteenth century miners. Toward the center of the state is a broad swath underlain by Cambrian sandstones, worked currently for “frac sand”. The bedrock in the northwestern part of the state is dominated by a continuation of the 1,100 million year old Midcontinent Rift from Michigan’s famous Keweenaw Peninsula. Although lacking in the bonanza copper deposits of Michigan, these rocks do contain similar minerals, most notably in Douglas County. The central part of the state contains granites and metamorphic rocks. Wisconsin’s state rock, red granite, comes from pits in this region. Some granitic rocks, notably in Marathon County, host interesting complex pegmatites. Across central Wisconsin is a 1,800 million year old volcanic belt that contains large massive sulfide deposits. Of these, the Flambeau Mine in Rusk County, produced many excellent mineral specimens. In the northeastern part of the state, Proterozoic banded iron formation of the Gogebic Range produced excellent specimens, particularly from the Montreal Mine in Iron County.
Commodity ListThis is a list of exploitable or exploited mineral commodities recorded from this region.
Mineral ListMineral list contains entries from the region specified including sub-localities
324 valid minerals. 1 (TL) - type locality of valid minerals. 1 (FRL) - first recorded locality of unapproved mineral/variety/etc.
Rock Types Recorded
Note: this is a very new system on mindat.org and data is currently VERY limited. Please bear with us while we work towards adding this information!
Rock list contains entries from the region specified including sub-localities
Select Rock List TypeAlphabetical List Tree Diagram
Entries shown in red are rocks recorded for this region.
- Igneous rock
- Normal crystalline igneous rock
- Exotic crystalline igneous rock
- ⓘ Pegmatite
- Sedimentary rock and sediment
- Metamorphic rock
- Unclassifed rock
- Lunar, meteorite and other extra-terrestrial rock and sediment