<Li> Lake Nipigon, connected to Lake Superior by the Nipigon River, is surrounded by sill - like formations of mafic and ultramafic igneous rock hundreds of meters high . The lake lies in the Nipigon Embayment, a failed arm of the triple junction (centered beneath Lake Superior) in the Midcontinent Rift System event, estimated at 1,109 million years ago . </Li> <Li> Green Bay is an arm of Lake Michigan, located along the south coast of the Upper Peninsula of Michigan and the east coast of Wisconsin . It is separated from the rest of the lake by the Door Peninsula in Wisconsin, the Garden Peninsula in Michigan, and the chain of islands between them, all of which were formed by the Niagara Escarpment . </Li> <Li> Lake Winnebago, connected to Green Bay by the Fox River, serves as part of the Fox--Wisconsin Waterway and is part of a larger system of lakes in Wisconsin known as the Winnebago Pool . </Li> <Li> Grand Traverse Bay is an arm of Lake Michigan located on Michigan's west coast, being one of the largest natural harbors in the Great Lakes . The bay has one large peninsula and one major island known as Power Island . Its namesake is derived from when Jacques Marquette crossed the bay from Norwood to Northport calling it La Grande Traversee . </Li>

Mercury in lakes and rivers in the northeastern us and great lakes