Current Year Schedule
GSM 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 concludes each seminar. The labs, also free and open to the public, allow a hands-on learning experience and demonstrate the ideas and principles of geology and earth science. Live lectures and labs require no registration; just show up a few minutes early on the evening of the lecture.
Click on date of any seminar for attendance information and other details. For a printable version of our schedule of seminars and labs, click here.
Except as noted, in-person lectures during winter/spring 2026 are Mondays at 7:00 PM CT on the University of Minnesota campus, Keller Hall, Room 3-210. A lecture with (V) following its title is an online virtual lecture. For these, free registration is required by non-members; the instructions are supplied with the lecture description.
Our schedule is planned over 6 months in advance, so changes may occur. Always check this website shortly before each lecture for the latest seminar information.
Winter weather will come and snow might impact our lectures. The GSM will make any decision about cancelling or postponing a lecture due to inclement weather no later than 3:00 PM the day of the lecture. This information will be posted on the GSM home page (http://www.gsmn.org/). So check our home page shortly before each lecture in case there is a cancellation or a last-minute change. Also, we will e‐mail lecture postponement and cancellation information to our members.
Past seminars marked with * were recorded and the recording is available on the Geological Society of Minnesota YouTube channel. Subscribe to this channel for updates.
Seminar Details
Seminar Lab Date: February 14, 2026
Seminar Lab Subject: Rocks and the Minerals that Define Them – an Exploration of Minerals that Make Up Common Rocks
Seminar Lab Presenter: Jeff Thole, M.Sc., Geology Laboratory Supervisor and Instructor at Macalester College
Link to Presenter https://www.macalester.edu/geology/facultystaff/jeffthole/
Second Link to Presenter https://www.linkedin.com/in/jeff-thole-9597bb11/
Seminar Lab Location:
Lab time is 10:00 AM to 12:00 noon (We suggest arriving at 9:45. The doors are card-access only; someone will be stationed at the south door (at least) to allow participants in. Olin Hall has lots of interesting specimens and exhibits on display.)
Macalester College Geology Dept., SW area of basement of Olin-Rice Science Center (Building 14), (south end of campus, by tennis courts). Park to the south or west of the building.
Meet in Room 100.
Road Map: https://maps.app.goo.gl/ibLTrhatU1QLPgBZ8
Seminar Lab Detail:
Lab Description: Common rocks within all three groups of the Rock Cycle are made up of a relatively small group of the more than 6,000 recognized mineral species. We’ll talk about what minerals are generally present within some common Igneous, Sedimentary, and Metamorphic rocks and how to recognize them. A brief explanation of how we classify rocks within each group will be included. GSM members will then be able to investigate hand samples of a variety of common rocks and their mineral components. Thin sections of common rocks within each major group will also be available to view with petrographic microscopes.
Biography: Jeff Thole is the Geology Laboratory Supervisor at Macalester College. He arrived at Macalester in 1996 after doing 5 years of environmental consulting. His work experience also includes spending a year as a geologist for the U.S. Geological Survey in Reston, Virginia. His primary duties include teaching introductory geology labs and maintaining, running, and user instruction for the instrumentation housed in the Macalester Science Division’s Keck Laboratory. Jeff received Master of Science in Geology from Washington State University in 1991 and Bachelor of Science in Geology from the University of Minnesota – Duluth in 1987.