11/24/25 The Rock Elm Meteor Impact Structure, Pierce County, WI: Discovery and Basic Geology скачать в хорошем качестве

11/24/25 The Rock Elm Meteor Impact Structure, Pierce County, WI: Discovery and Basic Geology

Presenter: Bill Cordua, Ph.D., Geology Emeritus, University of Wisconsin River Falls Presenter info: https://www.mindat.org/user-32096.html https://minds.wisconsin.edu/handle/17... Summary: The Rock Elm structure has been recognized as a geological anomaly for well over a century, attracting prospectors, charlatans and scientists. It is interpreted as formed by an extraterrestrial impact during the middle Ordovician 430-505 Ma. Both gold and diamonds are found in unusual quantities in the alluvium of streams draining the feature. The talk will outline its basic geological features, review the evidence for its interpretation as an impact structure, speculate why gold and diamonds are associated with it and relate it to similar features in the Midwest. Biography: Dr. Bill Cordua is a retired professor from the University of Wisconsin – River Falls where he taught geology for 40 years. He has published many technical articles and written over 100 articles for the general public on geology. Dr. Cordua is in the education division of the Rockhound and Lapidary Hall of Fame and has received the Katherine Greacen Nelson Award honoring those who have made outstanding contributions to the earth sciences in Wisconsin. General Info: GSM lectures/seminars with slide show presentations are free and open to the public. They are presented by leading professionals in their fields and are aimed at learners from high school to adult. A question-and-answer session follows each seminar. In-person lectures require no registration; just show up a few minutes early on the evening of the lecture. These lectures are eligible for 1 hour of Continuing Education Unit (CEU) credit. Our full schedule of lectures and labs is posted here: https://gsmnwp.geosocmn.org/current-y... Our schedule is planned over 6 months in advance, so changes may occur; always check our home page shortly before each lecture for the latest seminar information. More information here: https://gsmnwp.geosocmn.org/home/