CITATION

L. Gordon Medaris, Jr. - 2009 Goldich Medal Recipient

Gordon Medaris’s many and diverse contributions to the geology of the Lake Superior region, as well as his long-continued participation in ILSG over the past five decades, are appropriately recognized by the Goldich Medal.  Medaris’s broad interests make him difficult to pigeonhole. He is best known internationally as an igneous and metamorphic petrologist who has emphasized the study of eclogites and orogenic peridotites of the North American Cordillera, the Caledonides of Scandinavia, the Variscides of the central European Bohemian Massif and the Variscides of the  southern Carpathians. He has also studied mantle xenoliths from California, central Europe and the Middle East. Gordon’s European contributions have been recognized with two awards from Charles University of Prague, the Gold Medal of Science in 1998 and the Boricky Medal in 2006. It is fair to say that Gordon has developed a Bohemian love affair.

Better known to us is Gordon’s research in the Lake Superior region that began in the 1970s with a ground breaking study of the Wolf River batholith of east-central Wisconsin, which is part of a continental-scale Geon 14 magmatic event. That work was initiated in collaboration with Randy Van Schmus and Phillip Banks and was continued and expanded by his student J. Lawford Anderson. Next, Medaris studied with geochemist Robert Cullers the rare earth elements of the Seabrook Lake carbonatite and cogenetic alkaline rocks. By the 1980s, we find Gordon, Van Schmus, and student Randy Maass publishing syntheses of Penokean deformation and metamorphism across Wisconsin and adjacent areas. In 1983, Gordon was the principal convener and editor for an international symposium on Proterozoic Geology, which resulted in two GSA Memoirs, Number 160 being The Early Proterozoic Geology of the Lake Superior Region. Gordon, Dave Moecher, and others then studied the metamorphic conditions of Sam Goldich’s favorite high-grade gneisses in the Minnesota River Valley.

Since retiring in 1998, Medaris has redoubled his research efforts in the Lake Superior region with collaborations that culminated in 2003 in the benchmark Journal of Geology article about the age, composition, and metamorphism of Baraboo Interval rocks and their tectonic significance. Gordon’s discovery of a paleosol beneath the Baraboo Quartzite and the previous recognition of paleosols beneath the Barron and Sioux Quartzites have important paleoclimatic implications, which he has discussed. He also has helped archaeologists to resolve pipestone artifact provenance by characterizing two distinct mineral assemblages in pipestone quarries -- hematite-quartz-kaolinite in the Barron and hematite-muscovite-pyrophyllite-diaspore in the Sioux and Baraboo Quartzites. Six journal articles have appeared from these Baraboo Interval investigations and we are still counting.

Besides the full-length publications alluded to above, Gordon has contributed talks at no less than 21 ILSG meetings beginning in 1973. He also has been a major organizer of three different ILSG field trip guidebooks (1973, 1986, and 2001) and all of us have seen him on many other ILSG field trips. As many of you know, Gordon is a superb field and laboratory petrologist and mineralogist. Like Sam Goldich, he is gifted with the vision to spot a significant problem, to work out a research strategy, and to pursue it by whatever techniques are needed to answer critical questions. Gordon likes collaborative research, so does not hesitate to recruit colleagues from any specialty to work with him. All of us who have had the privilege to work with Gordon appreciate his vision and encouragement in these joint efforts. He never tries to dominate and is quick to give encouragement and credit, all with a wonderful quiet dignity. I know that I speak for many other co-workers in thanking Gordon for sharing the pleasure of his collaborations.

For his many, varied and fundamental contributions to our knowledge of Lake Superior Geology and for his stimulation of the efforts of others, Randy Van Schmus, Daniel Holm, and Brad Singer join me in presenting L. Gordon Medaris, Jr.  as the 2009 recipient of the Goldich Medal.

R. H. Dott, Jr.
April, 2009