Illinoian (stage)

The Illinoian Stage is the name used by Quaternary geologists in North America to designate the period of geologic time of ~191,000—130,000 years ago, a period of ~ during the middle Pleistocene when sediments comprising the Illinoian Glacial Lobe were deposited. It precedes the Sangamonian stage and follows the Pre-Illinoian Stage in North America. The Illinoian Stage is defined as the period of geologic time during which the glacial tills and outwash, which comprise the bulk of the Glasford Formation, accumulated to create the Illinoian Glacial Lobe.