Explorers invest in locations where they believe the geologic conditions are prospective to contain undiscovered mineral deposits, based upon known mine locations with similar geologic conditions in other parts of the world.
There has been exploration for copper and nickel deposits in the bedrock unit called the Duluth Complex in St. Louis and Lake Counties, since the discovery of copper and nickel mineralization there in 1948. Platinum and palladium were discovered in the Duluth Complex in 1986. Known deposits of titanium have been found in oxide-bearing ultramafic intrusions of the Duluth Complex.
Map of Duluth Complex Exploration » as of August 2016
The Midcontinent Rift's Tamarack intrusion in Aitkin County is being actively explored and is known to host copper and nickel mineralization. The Midcontinent Rift is a feature that formed when tectonic forces pulled the continent apart.
Map of Tamarack Intrusion Exploration » as of March 2017
Midcontinent Rift Graphic »
The greenstone terrane that host many of Canada's richest gold camps continue across the U.S. border and into the northern portion of Minnesota. There has been gold exploration in the greenstone terranes of Minnesota for more than 100 years. There are many bedrock locations that contain economic quantities of gold, but so far only small tonnages have been found. One example is near the cities of Virginia and Gilbert, just north of the iron mines. Currently there is gold exploration occurring in St. Louis, Itasca, and Koochiching counties.
Map of Greenstone Terrane Exploration » as of March 2017
There are private mineral leases in virtually all the same areas as the active state mineral leases. These are on privately owned lands, so the state does not have locations for them, except where a company discloses the lease in a public way such as on a website. There is also exploration for copper and nickel on private (not state) mineral leases in southern MN.