Date of Graduation
Summer 2025
Degree
Master of Science in Geography & Geology
Department
School of Earth, Environment & Sustainability
Committee Chair
Kevin Mickus
Abstract
The Archean basement geology of northwest Minnesota, a region covered by glacial deposits and historically underexplored for minerals, was analyzed using gravity, magnetic, radiometric, and geochemical data. These datasets were integrated to aid in identifying subsurface structures and evaluating the area's potential for economic mineralization within the Wabigoon, Quetico, and Wawa Subprovinces of the Superior Province. Gravity and magnetic datasets, analyzed through upward continuation, derivative maps, and two-dimensional modeling, revealed distinct northeast-to-southwest-trending maxima corresponding to fault-bounded, high-density, and magnetically susceptible bodies. These features were interpreted as mafic to ultramafic intrusions and dikes, several of which align with known Proterozoic fault systems and Archean structural contacts. In particular, the Mentor Anorthosite Intrusive Complex (MAIC) and associated feeder structures were imaged in detail, suggesting a layered intrusive system with possible mineralizing pathways. Geochemical data revealed elevated concentrations of gold (Au), nickel (Ni), copper (Cu), chromium (Cr), and cobalt (Co), often near gravity and magnetic anomalies linked to intrusions and fault zones. Radiometric ratios (Th/K, U/Th, U/K) further supported these findings by highlighting uranium and thorium enrichment zones, suggesting areas of hydrothermal alteration or felsic intrusion. The above datasets, when integrated, indicate that northwest Minnesota hosts structurally controlled mineral systems comparable to those found elsewhere in the Superior Province. Based on these results, areas surrounding the MAIC, the southern Wawa Subprovince fault zones, and portions of the Quetico Subprovince contain geophysical and geochemical anomalies that are recommended for future exploration targeting critical minerals. This study demonstrates the effectiveness of integrating geophysical and geochemical methods in regions with limited outcrop exposure, providing a valuable framework for future exploration and resource assessment in underexplored Archean terranes.
Keywords
geophysics, radiometric, geochemical, density, magnetic susceptibility, critical minerals, Superior Province
Subject Categories
Geology | Geophysics and Seismology | Mineral Physics
Copyright
© Michell L. Waterman
Recommended Citation
Waterman, Michell L., "Critical Mineral Exploration in the Superior Province of Northwestern Minnesota - A Geophysical Data Analysis" (2025). Graduate Theses/Dissertations. 4079.
https://bearworks.missouristate.edu/theses/4079
Open Access
