The North American Midcontinent Rift System is a major metallogenic feature that contains
This study is part of a comprehensive USGS data acquisition and multidisciplinary research effort to image and characterize the Midcontinent rift and related mineral resources, to document mineral resource potential, and to evaluate mineral environmental impact of past and future mineral resource development in the region.
Researchers will study the sediment-hosted copper deposits of the Midcontinent Rift to address these questions:
Contact: Jeff Mauk, firstname.lastname@example.org
Our objectives are to describe the ore mineralogy and geochemistry of the Copperwood deposit. We will use modern analytical methods (petrographic analysis, SEM, microprobe, LA-ICP-MS) to document the silver and mercury in the ore minerals and to test for the presence of other critical and strategic elements in the ore minerals. We will collect whole rock geochemical data from the host rock Nonesuch Formation to test for geochemical fingerprints that can reflect widespread hydrothermal alteration.
Contact: Timothy Hayes, email@example.com
We are evaluating whether hydrothermal alteration in footwall rocks can be used as a vector towards ore. We will use whole rock geochemistry and petrography to test for sodium alteration of the aquifer and (or) source rocks related to copper mobilization and transport through the Copper Harbor Conglomerate by ore fluids en route to the White Pine and Copperwood deposits.
Contact: Cliff Taylor, firstname.lastname@example.org
We will compile and review studies of the Kupferschiefer deposits to document the location of gold (Au) and platinum-group element (PGE) mineralization in the deposits. The resulting information will be used to determine the lithostratigraphic horizons that are mostly likely to contain these elements in the Midcontinent Rift region and the location where those horizons might be mineralized.
Gallagher, T.M., Sheldon, N.D., Mauk, J.L., Petersen, S.V., Gueneli, N., and Brocks, J.J., 2017, Constraining the thermal history of the North American Midcontinent Rift System using carbonate clumped isotopes and organic thermal maturity indices: Precambrian Research, 294, p. 53-66, doi:10.1016/j.precamres.2017.03.022.
Stewart, E.K., and Mauk, J.L., 2017, Sedimentology, sequence-stratigraphy, and geochemical variations in the Mesoproterozoic Nonesuch Formation, northern Wisconsin, USA: Precambrian Research, 294, p. 111-132, doi:10.1016/j.precamres.2017.03.023.
Stewart, E.K., and Mauk, J., 2016, Sequence stratigraphy and basin evolution of the Mesoproterozoic Nonesuch Formation, Ashland syncline, northern Wisconsin: 62nd Institute on Lake Superior Geology Proceedings v. 62, Part 1-Program and Abstracts, p. 141-142. View ILSG 2016 abstract book. [PDF file, 13.8 MB]
Central Mineral and Environmental Resources Science Center
Geology, Minerals, Energy, and Geophysics Science Center