Invited Luncheon Speaker - March 4, 2008, Mark Jirsa, Minnesota Geological Survey

What Forest Fires in the BWCAW Reveal: Volcanic Eruptions, Meteorite Impact, and other Natural Disasters.

Abstract

This presentation is an overview of bedrock geologic mapping in parts of the Boundary Waters Canoe Area Wilderness that were burned during recent forest fires. The Cavity Lake Fire of 2006 (32,000 acres) and Ham Lake Fire of 2007 (117,000 acres) were the delayed result of a mega blow-down caused by severe storms in 1999. The storms reduced the woods to almost impenetrable--the fires and subsequent rains opened the woods and cleaned the outcrops to reveal amazing details about the geologic history of this complex region.

Biography

Mark Jirsa
Minnesota Geological Survey
2642 University Avenue
St. Paul, MN 55114-1057
Phone: 612-627-4780 X208
Fax: 612-627-4778

Mark was reared in Iowa and Wisconsin (making him the brunt of both corn and cheese-head jokes). He was trained in “classic” Precambrian and economic geology; receiving a BS degree from the University of Wisconsin-Eau Claire, and an MS from the University of Minnesota-Duluth. Mark is a senior scientist and geologic mapper with the Minnesota Geological Survey. His work over nearly 30 years utilizes the combination of geophysical, drill core, and outcrop information to improve and convey the understanding of Minnesota's Precambrian terrains. Born in Iowa, raised in Wisconsin, and transplanted to Minnesota--explains why he likes corn and cheese on his hot-dish.