Portrait Photograph of Esther K. Stewart

Esther Stewart


Division of Extension | Madison

Esther K. Stewart is a geologist with the Wisconsin Geological and Natural History Survey where she uses geologic mapping to address questions about the rocks that underlie Wisconsin. Prior to joining the state survey, she worked for ExxonMobil in Houston, TX. She has a masters degree from Idaho State University.


  • This talk describes how geologic mapping and historic mining records from the early 1900s has helped piece together what WI was like over 1.5 billion years ago.

  • Nearly one billion years ago, beneath what is now Lake Superior, lava flowed from shield volcanoes and fissures. This talk describes what the environment may have been like as this Midcontinent Rift developed.

  • Wisconsin’s bedrock geology hosts metallic mineral deposits. This talk describes how WI geology influences the potential for metallic mineral development.