George Hudak
Adjunct Assistant Professor (University of Wisconsin, Oshkosh)
Ph.D. University of Minnesota

Interests: volcanology, synvolcanic intrusions, volcanic-associated ore deposits, synvolcanic hydrothermal alteration
Courses taught: None
Office: U Wisconsin - Oshkosh
Phone: (920) 424-4463
E-mail: hudak@uwosh.edu
Website: http://www.uwosh.edu/faculty_staff/hudak/

The emphasis of my research is field-oriented studies of ancient subaqueous volcanic systems and associated mineral deposits (primarily volcanic-hosted massive sulfide deposits (VHMS)). Since 1986 I have been working with Dr. Ron Morton (UMD) and Dr. James Franklin (Geological Survey of Canada) on deciphering the physical volcanology, igneous petrology, and alteration mineralogy and geochemistry associated with the Archean Sturgeon Lake Caldera Complex and its associated VHMS deposits. The most recent efforts in this area have been related to: a) determining depositional mechanisms for the subaerial and subaqueous tuffs and lapilli tuffs that comprise a large portion of the intracaldera fill; b) GIS analysis with Dr. Dean Peterson (NRRI) to evaluate eruptive volumes for intracaldera tuffs in the Sturgeon Lake Caldera Complex; and c) trace element geochemical fingerprinting of synvolcanic intrusive rocks associated with and post-dating the Sturgeon Lake Caldera Complex. We are currently completing the lithological description of the caldera, and developing a model for the caldera's complex geological history. Since 1998, I have focussed much of my research on evaluating the physical volcanology, igneous petrology, syn- and post-volcanic hydrothermal alteration and mineralization within the Lower Member of the Ely Greenstone in the Vermilion District of northeastern Minnesota. This field-oriented research (supplemented by detailed petrographic and geochemical studies) has further refined our understanding of the volcanic environments, hydrothermal alteration processes, and mineral chemistry of hydrothermal alteration zones in the Vermilion District. Future work will encompass detailed evaluations of peperite deposits in the Lower Ely Greenstone, as well as field and lithogeochemical evaluations of possible synvolcanic intrusions in the Vermilion District. Additional future work is currently being proposed to study the physical volcanology, stratigraphy, and hydrothermal alteration associated with VHMS mineralization in the western part of the Abitibi Greenstone Belt in Ontario.

Publications:

Hudak, G. J,Peterson, D. M., Morton, R. L., and Franklin, J. M., in review, Geographic Information System Analysis of the Sturgeon Lake Caldera Complex, NW Ontario: Implications for the Development of Archean Ash Flow Calderas, submitted toGeology, January 2003.

Hudak, G. J.,Morton, R. L., Franklin, J. M., and Peterson, D. M., in press, Morphology, distribution, and estimated eruption volumes for intracaldera tuffs associated with volcanic-hosted massive sulfide deposits in the Archean Sturgeon Lake Caldera Complex, northwestern Ontario: American Geophysical Union Geophysical Monograph on Subaqueous Explosive Volcanism.

Hudak, G. J., Heine, J., Newkirk, T. T., Odette, J. and Hauck, S., in press, ComparativeGeology, Stratigraphy, and Lithogeochemistry of the Five Mile Lake, Quartz Hill, and Skeleton Lake VMS Occurrences, Vermilion District, NE Minnesota: Minerals Coordinating Committee Report, State of Minnesota.

Hudak, G. J., Heine, J., Hocker, S., and Hauck, S. A., 2002, Geological mapping of the Needleboy Lake Six Mile Lake Area, northeastern Minnesota: A summary of volcanogenic massive sulfide potential: Natural Resources Research Institute Report of Investigation NRRI/RI-2002/14, 16 pages.

Hudak, G. J., Morton, R. L., Franklin, J. M., Peterson, D. M., Walker, J. S., Jongewaard, P. K., and Murphy, C., in preparation, Stratigraphy and volcanological evolution of the Archean Sturgeon Lake Caldera Complex, NW Ontario

Hudak, G. J., Newkirk, T. T., and Odette, J. D, in preparation, Pillow lava morphology in the vicinity of Five Mile Lake, Vermilion District, NE Minnesota: Implications for VHMS Exploration.

Hudak, G. J., 2000, Vermilion District VMS Studies: Minnesota Prospector, v. 8, no. 2, p.15-18.

Gibson, H. L., Morton, R. L., and Hudak, G. J., 1999 Submarine volcanic processes, deposits and environments favorable for the location of volcanic-associated massive sulfide deposits: Reviews in EconomicGeology, v. 8, p. 13-48.

Morton, R. L., Walker, J. S., Hudak, G. J., and Franklin, J. M., 1991, The early development of an Archean submarine caldera complex with emphasis on the Mattabi ash flow tuff and its relationship to the Mattabi massive sulfide deposit: EconomicGeology, v. 86, no. 5, p. 1002-1011.