Precambrian Research Center

Students supported by the
Precambrian Research Center

A primary objective of the PRC is to provide financial and advisory support to graduate and undergraduate students conducting field-based research on the Precambrian geology of the Lake Superior region. This support comes in the form of graduate research assistantships, which are limited to UMD graduate students, and research grants, which are available to undergraduate or graduate students from any school. The extent to which the PRC can provide such support will vary based on the annual level of Corporate and Individual Membership contributions.

Student: Chris White
Status: 2nd year MS candidate at UMD
Primary Advisor: Jim Miller
Co-advisors: John Goodge, Dean Peterson

PRC Support: 1/2-time graduate research assistantship for the 2007-08 academic year

Thesis title: The Magmatic Evolution and Cu-Ni-PGE Mineralization of the Northern South Kawishiwi Intrusion, Duluth Complex, Northeastern Minnesota.

Research Description: My thesis work focuses on understanding the igneous petrology and sulfide mineralization of a portion of the 1.1 Ga South Kawishiwi intrusion (SKI), which occurs along the northwestern margin of the Duluth Complex in northeastern Minnesota, Previous studies of the SKI (Severson, 1994) show it to have formed by multiple injections of tholeiitic magma to produce a complex igneous stratigraphy.  Economic grades of Cu-Ni-PGE enriched sulfide occur along the <100m-thick basal zone of the 2+km-thick intrusion and several deposit areas are presently being evaluated for development by various mineral exploration companies.  My work will focus on the Maturi and Nokomis deposits, which occur in northern part of the SKI and are under lease by Duluth Metals, Inc..  Two general styles of mineralization are noted in these deposits: a low-grade, large volume type called open-style and a higher-grade, lower-volume type called confined style (Peterson, 2001).  A major objective of my thesis is to better characterize these contrasting mineralization styles and to test a model proposed by Peterson (2001) that explains the two styles as reflecting different hydrodynamic conditions of sulfide-bearing magma flow under and around a large inclusion block of older gabbroic anorthosite.  My methods of investigation will involve field mapping, drill core logging, petrographic observations, microprobe analysis, and whole rock geochemistry.  This research will result in a more detailed characterization of the igneous stratigraphy and sulfide mineralization and which will in turn lead to a better understanding of the magmatic and metallogenic evolution of the South Kawishiwi intrusion.

References
Peterson, D.M., 2001, Development of a conceptual model of Cu-Ni-PGE mineralization in a portion of the South Kawishiwi intrusion, Duluth Complex, Minnesota: Society of Economic Geologists, Second Annual PGE Workshop, Sudbury, Ontario.

Severson, M.J., 1994, Igneous stratigraphy of the South Kawishiwi Intrusion, Duluth Complex, northeastern Minnesota: NRRI/TR-93/34, 210 p.