The Michigan Basin is a geologic basin centered on the lower peninsula of the US state of Michigan. The feature is represented by a nearly circular pattern of geologic sedimentary strata in the area with a nearly uniform structural dip toward the center of the peninsula.
The basin is centered in Gladwin County where the rocks are 16,000 feet (4,900 m) deep. Around the margins, such as under Mackinaw City, Michigan, the surface is around 4,000 feet (1,200 m) down. This 4,000-foot (1,200 m) contour on the bedrock clips the northern part of the lower peninsula and continues under Lake Michigan along the west. It crosses the southern counties of Michigan and continues on to the north beneath Lake Huron.
The eastern margins of Wisconsin along Green Bay are along the margins of the basin. The northeastern margin of Illinois around Chicago are on the southwestern margin of the basin. The southwest boundary of the basin underlies
The rocks of the Michigan Basin are the source of commercial quantities of petroleum. The most actively drilled-for source of natural gas in recent years has been shale gas from the Devonian Antrim Shale in the northern part of the basin.