Events

DETAILS OF NEXT TALK – December 18th

The 2015 SGS Montana Fieldtrip: Stillwater Complex, Sappington Formation, Shonkin Sag and Laccolith – Ralf Maxeiner
ABSTRACT

The following text is pasted from a previous newsletter in which I reported on the field trip. The first field trip day was the most exciting for me, as we visited the 2.7 Ga Stillwater Complex. Our very knowledgeable guide Ennis P. Geraghty, Senior Project Geologist with Stillwater Mining Company, did a great job of taking us up the narrow winding roads, which allowed us access of the entire layered ultramafic-mafic complex. We got to see the three mineralized horizons (JM reef, basal Cu-Ni mineralization and chromitite layers), as well as the famous inch-scale-layering. What awesome geology. We also manage to get the two vans stuck and it took some fancy driving and a bit of pushing to get out of this one. I had brought home some samples but sadly Mike Thomas stole them all, despite the promise of some garter snakes. To finish the day off, Ennis’ truck broke down and Kim Kreis’ van had to tow him to the next gas station. We were the safety follow vehicle and wondered why Kim kept speeding up, despite the dangerously short (6 feet) tow chain. We later learnt that Mike Thomas, who was in Ennis’ truck, told Kim over the walkie-talkie “ no faster”, which all occupants of Kim’s van understandably heard as “go faster”. Made it to Bozeman pretty late that day and went to the best restaurant of the trip, the only reason we got a table was that we didn’t get to the restaurant until 9:30.

The second day was spent in the Bozeman area, where we not only saw lots of deer but also got treated to the Sappington Formation, a Bakken equivalent. Our guide Michael Hofmann, a Prof from the Department of Geosciences from the University of Montana in Missoula, was also a great field trip leader. He was aided by two of his grad students, both really nice and knowledgeable. My highlight of that day was the boundary between the Carboniferous and Devonian, some crossbedded dolomitic siltstones, some bioturbated sediments and a few crinoids. After that we went on a pretty amazing drive through the Belt Supergroup and some Tertiary intrusives and volcanics on the way to Great Falls. Evening ended with some outstanding pizza, a bunch of beer and great company.

The third and final day was spent in the Great Falls area. Our guides took us through the Shonkin Sag and eponymous alkaline laccolith were Chris J. Croff, a geological engineer, and Mr. Ron Long (a local rancher),

both from the Highwood Mountain area. A great day, very hot and very smoky. The Shonkin Sag is a glacial spillway of biblical proportions and the laccolith is famous for the plutonic rocks, shonkinite, that were first described and named in this area; we also saw some phonolite and lamprophyre (minette) dykes.

All in all, a really fun and educational trip! All participants were enthusiastic, the guides were knowledgeable and our fieldtrip organizers and drivers, John Lake, Mike Thomas, Kim Kreis, and Brian Brunskill did a wonderful job putting it all together and keeping us organized.

BIOGRAPHY – Ralf Maxeiner
Born and raised in Germany, near the town of Wetzlar (where Leitz microscopes used to be made) Ralf Maxeiner obtained his undergraduate degree at the Justus Liebig Universität in Giessen in 1989. After a short stint at the University of Aachen near the Dutch-German-Belgian border he took a summer job with Uranerz Exploration as a summer student in 1990, undertaking gold exploration in the La Ronge Domain and a little bit of Uranium exploration in the Athabasca Basin. Subsequent to that, Ralf started an M.Sc. degree at the University of Regina under the combined supervision of Dr. Brian Watters, Dr. Pier Binda and his mentor Dr. Tom Sibbald. His thesis was a field-based study on the geochemistry and economic geology of the Hanson Lake volcanogenic massive sulphide camp. He has worked under contract for the Geological Survey of Canada, the University of Regina and has been a project geologist with the Saskatchewan Geological Survey since 1995. Ralf loves teaching his summer students geological field techniques and has been known to on occasion to test their physical abilities, although that is becoming increasingly more difficult.