MBGS Monthly Meetings
Monthly Meetings take place typically on the second Wednesday of each month from September through
May. The meetings are open to all. The Executive Committee Officers meet prior to the meeting to discuss
Society issues and is open to anyone interested in attending.
Meetings hosted by the Michigan Basin Geological Society have been moved to the Natural Sciences Building, MSU
Campus, for more information contact Peter Rose at RoseP1@michigan.gov. The lecture ends usually no later than 9:00.
Next MBGS Meeting
Michigan Basin Geological Society
October 9, MBGS Membership Meeting
When: November 13, 2019.
Executive committee meeting at 4:30 PM (members welcome) Claddagh Irish Pub & Restaurant,
2900 Towne Center Blvd. Lansing, MI 48912
Presentation - 7:00-8:00 PM
Where: Natural Science Building, Rm 204 Michigan State University, East Lansing, Michigan
Speaker: Dr. Robb Gillespie, Assistant Professor with the Department of Geological and Environmental Sciences, a Research Associate with the Michigan Geological Repository for Research and Education (MGRRE), and an associate of the Michigan Geological Survey, all located at Western Michigan University.
Presentation: Interactions of Late Wisconsin Saginaw and Michigan Glacial Ice-lobes in Michigan - Possible Michigan Lobe Event Defined
Traditionally, the extent of the Late Wisconsin Saginaw Lobe ice advance throughout Michigan has been delineated in the landscape by a belt of glacial moraines surrounding Saginaw Bay. However, new satellite imagery, DEMs, and LiDAR data sets have provided the basis for renewed, more detailed, analyses of previously mapped glacial landforms, drainage basins and associated river patterns. Analyses of the cross-cutting relationships of these features, combined with: (1) development of a more detailed, bedrock-topography map, and (2) sedimentary analyses of more than 320 newly collected Saginaw Moraine till samples, now makes it possible to re-interpret certain Michigan glacial events.
The hypothesis presented in this work focuses on the central portion of the Saginaw Lobe – Lake Border Moraine system (centered at Ithaca, Michigan in Gratiot County). It is postulated that the present-day, central portion of this series of moraines, rather than being produced by Saginaw Lobe ice advancing from the northeast (as traditionally interpreted), was instead produced by younger Michigan Lobe ice advancing from the west. Ice-flow directions are thought to be directly related to, and controlled by, bedrock topography. Advancing Michigan Lobe ice re-worked the central portion of the Saginaw Lobe – Lake Border Moraine system originally deposited by Saginaw Lobe ice, and re-deposited this material farther eastward, resulting in the eastward “bulge” of the central portion of the overall moraine system.
Development of stream drainage patterns also indicates westward retreat of glacial ice from this area. Current patterns are thought to have formed contemporaneously with moraine deposition. This pattern could only develop if eastward valleys were ice-free during a time when adjacent western valleys were still ice covered. Also, moraine patterns and landform features to the west of the area are consistent with landform systems-tracts formed by ice retreating west – northwest.
Recently, sediment analyses of till samples collected from the Saginaw Lobe – Lake Border Moraine system display compositions for the central portion of the moraine system that are different from those of the northern and southern portions. This implies a distinctly different genesis for this portion of the Saginaw Lobe – Lake Border Moraine system.
Therefore, it is hypothesized that the central portion of the currently defined Saginaw Lobe – Lake Border Moraine system was formed by younger Michigan Lobe ice advancing from the west, rather than by older Saginaw Lobe ice advancing from the northeast (which formed the laterally contiguous, older portions of the Saginaw Lobe – Lake Border Moraine system).
Dr. Robb Gillespie is an Assistant Professor with the Department of Geological and Environmental Sciences, a Research Associate with the Michigan Geological Repository for Research and Education (MGRRE), and an associate of the Michigan Geological Survey, all located at Western Michigan University. He has been at WMU for the past sixteen years. Prior to this, he concurrently held geological teaching positions at Richland Community College and Collin County Community College in Dallas, Texas, while also employed full-time as an exploration geologist in the oil and gas industry.
Dr. Gillespie has more than 34 years of experience in the oil and gas industry. He worked 13 years for ARCO Oil and Gas in their domestic, international, and research groups. Then, in 1992, he co-founded Tres Rios Resources, Inc., an independent, Texas-based oil and gas company. He served as vice-president of that company until 2013 when he sold his interests to corporate partners.
During 1993-95, he consulted for the United States Department of Justice providing expert geological exploration review for a 1.2 billion dollar lawsuit between the Federal Government and ten of the world’s largest oil companies.
Dr. Gillespie’s geological specialties are:
(1) Oil/Gas/Water reservoir delineation and characterization based on detailed stratigraphic analysis.
(2) Detailing glacial events based on sedimentary depositional environments and associated geomorphological landforms.
He is currently focused on remapping glacial deposits, and better understanding glacial events, in central Michigan. He also continues to develop and teach undergraduate geology courses for the Department of Geological and Environmental Sciences at Western Michigan University.