The Michigan Basin is one of the world’s important sedimentary basins that contains significant quantities of evaporites. Here, evaporites are found in deposits of Ordovician through Mississippian age rocks; however, most of the thick evaporite accumulations occur in Silurian and Devonian intervals. Halite is most significant in the Silurian Salina Group, with a maximum aggregate thickness of halite exceeding 650 m (2150 ft). During the earliest evaporite deposition in the Salina Group (A-1 Evaporite), sylvite was widely deposited in the north-central portion of the basin within the upper 91.4 m (300 ft) of the formation. Devonian salt is also...