The Mineral Lake Intrusive Complex is an example of a layered and differentiated mafic intrusive complex within the Mesopaleozoic Mid-Continent Rift in the Lake Superior region. This intrusive complex hosts Ni-Cu-PGE mineralization discovered in the 1960’s via electromagnetic geophysical surveys and at least 16 drill holes were completed. Within increasing demand for domestic critical mineral product to supply metals for energy, communication, and miliary infrastructure, prospects like the Mineral Lake Ni-Cu-PGE showing are increasingly important. This project aims to describe the mineralogy of the sulfide inclusions and the host intrusion geochemistry to better understand the geological characteristics of the mineralized portion of the Mineral Lake Complex. Two drill holes were re-logged (WIS-12 and WIS-11) and samples were collected to represent the range of intrusive phases and mineralization types. Micron-scale PGE-bearing mineral phases are described using the SEM-EDS. Mineralization is hosted in either gabbro or anorthosite phases of the intrusion and are found as mm-scale sulfide segregations composing 1-10% of the rock. Analysis on the SEM-EDS has shown PGE mineralization is commonly hosted in Fe-Ni sulfides. Preliminary results are improving our understanding of economic significance of Mid-continent Rift magmatism.
