Visited Upper Michigan when our brother was teaching at Northern Michigan in 1981. Overnight trip to the Keweenaw and Copper Harbor. We walked the beach enjoying pebbles with sparkles of copper in them, but when trying to find some of the old mines back in the woods, clouds of gnats in our eyes and nose demolished our intrepid spirits. Butte will always be "the richest hill", but mineralized UP is fascinating and beautiful. Thanks for this post, interesting that there are organic remains.
Interesting discussion. I did my geology field camp w Michigan Tech because in the early 80s it was the least expensive field school I could find. Not sure I’ve seen a prettier rock than Copper Harbor Conglomerate. Also fascinating that just one county away we have the tremendous Marquette iron deposits.
Love the piece about UP Precambrian geology. I spent April-November seasons of 1981 and 1982 on a diamond exploration project based in Crystal Falls, MI, near to the discovery outcrop of the Lake Ellen kimberlite. In the rush begat by a US Steel field geologist's discovery of kimberlite exposed in a wheel rut in a logging road in 1977, a goodly number of kimberlites were discovered by surface sampling, airborne EM, and airborne mag. Some were slightly diamondiferous, but none with economic quantities of gem grade stones. The US Steel guy was good--he identified the rock as kimberlite in the field on the day he found it--no kimberlites had previously been identified anywhere in the UP until his discovery. Along the way of sampling pretty much the whole of the UP from the western edge of the Michigan Basin well into Wisconsin with a crew of 20-25 field people, I acquired a sample of the Nonesuch with native copper in the interstices. It's a nice looking piece which I need to locate at see about putting a urethane coating on to bring out the copper.
That it was: The small exploration consulting firm I worked for was hired by Sibeka, a Belgian mining company with operations in South Africa. By the late 1970s, with the political and social upheaval under way in SA, Sibeka decided to explore in stable geo-political environments rather than find more diamond mines in less-stable areas. They arrived in Bloomington, IN by early 1980 with a $20 million, 20 year budget to find a mine in the US or Canada. We Southern boys had the terrific opportunity to learn from some of the best field geologists I encountered in my brief career as a mineral exploration field geologist. Those South Africans of British and Dutch descent really knew their stuff!
I knew Derek Fullerton of ExMin (the Sibeka subsidiary in Bloomington) - we were both on the external Advisory Board of the Geology Dept. at IU. I did an interpretation of a magnetic survey for them in northern Montana. http://www.gravmag.com/nwmt.shtml (this is an old page, the data are probably no longer available and I don't even know for sure who has the rights any more).
That's awesome, Dick. Come to think of it, I think Derek was of Irish descent but lived in SA for most of his life before coming to Bloomington. One of my old co-workers at North American Exploration updated me on Derek and his sidekick, geologist Wim Kramer (aka The Dutchman) and I think they've both passed on now. Looks like the mag survey they flew north of Cut Bank was on the southwest side of the Sweet Grass Hills and not in the midst of the several (many?) diatremes scattered along the north side of the Missouri in the Breaks. I've assumed that Exmin and others looked at the diatreme region, and it's most likely that Jay Gatten's North American Exploration provided whatever field geologist/geophysicist services required up there out of their Salt Lake City area headquarters office. But no doubt, at least to me, that Derek and Wim really knew their stuff. Great experience working for them.
I've read about the lack of sulfur in the rocks there. So much less acid- ruining of the water from mining; The UP is a nice tourist/nature area, not just an acidified wasteland like it could be.
Fascinating. I never knew about this midcontinent rift. Yet another reason to make my way again to this region!
Visited Upper Michigan when our brother was teaching at Northern Michigan in 1981. Overnight trip to the Keweenaw and Copper Harbor. We walked the beach enjoying pebbles with sparkles of copper in them, but when trying to find some of the old mines back in the woods, clouds of gnats in our eyes and nose demolished our intrepid spirits. Butte will always be "the richest hill", but mineralized UP is fascinating and beautiful. Thanks for this post, interesting that there are organic remains.
Interesting discussion. I did my geology field camp w Michigan Tech because in the early 80s it was the least expensive field school I could find. Not sure I’ve seen a prettier rock than Copper Harbor Conglomerate. Also fascinating that just one county away we have the tremendous Marquette iron deposits.
My first multi-day geology field trip was to that area (from Flint Junior College). Fascinating geology and beautiful country.
Acritarch - meaning I don't know what it is but here's a word to make it sound as if I do. Useful one!
Love the piece about UP Precambrian geology. I spent April-November seasons of 1981 and 1982 on a diamond exploration project based in Crystal Falls, MI, near to the discovery outcrop of the Lake Ellen kimberlite. In the rush begat by a US Steel field geologist's discovery of kimberlite exposed in a wheel rut in a logging road in 1977, a goodly number of kimberlites were discovered by surface sampling, airborne EM, and airborne mag. Some were slightly diamondiferous, but none with economic quantities of gem grade stones. The US Steel guy was good--he identified the rock as kimberlite in the field on the day he found it--no kimberlites had previously been identified anywhere in the UP until his discovery. Along the way of sampling pretty much the whole of the UP from the western edge of the Michigan Basin well into Wisconsin with a crew of 20-25 field people, I acquired a sample of the Nonesuch with native copper in the interstices. It's a nice looking piece which I need to locate at see about putting a urethane coating on to bring out the copper.
Nice - that sounds like a cool project.
That it was: The small exploration consulting firm I worked for was hired by Sibeka, a Belgian mining company with operations in South Africa. By the late 1970s, with the political and social upheaval under way in SA, Sibeka decided to explore in stable geo-political environments rather than find more diamond mines in less-stable areas. They arrived in Bloomington, IN by early 1980 with a $20 million, 20 year budget to find a mine in the US or Canada. We Southern boys had the terrific opportunity to learn from some of the best field geologists I encountered in my brief career as a mineral exploration field geologist. Those South Africans of British and Dutch descent really knew their stuff!
I knew Derek Fullerton of ExMin (the Sibeka subsidiary in Bloomington) - we were both on the external Advisory Board of the Geology Dept. at IU. I did an interpretation of a magnetic survey for them in northern Montana. http://www.gravmag.com/nwmt.shtml (this is an old page, the data are probably no longer available and I don't even know for sure who has the rights any more).
That's awesome, Dick. Come to think of it, I think Derek was of Irish descent but lived in SA for most of his life before coming to Bloomington. One of my old co-workers at North American Exploration updated me on Derek and his sidekick, geologist Wim Kramer (aka The Dutchman) and I think they've both passed on now. Looks like the mag survey they flew north of Cut Bank was on the southwest side of the Sweet Grass Hills and not in the midst of the several (many?) diatremes scattered along the north side of the Missouri in the Breaks. I've assumed that Exmin and others looked at the diatreme region, and it's most likely that Jay Gatten's North American Exploration provided whatever field geologist/geophysicist services required up there out of their Salt Lake City area headquarters office. But no doubt, at least to me, that Derek and Wim really knew their stuff. Great experience working for them.
I've read about the lack of sulfur in the rocks there. So much less acid- ruining of the water from mining; The UP is a nice tourist/nature area, not just an acidified wasteland like it could be.
Yeah. Butte, Ducktown, and others won the acid drainage race! :)