The Trenton and Black River Formations of the Michigan Basin have been diagenetically altered by a complex sequence of events related to both the stratigraphic and structural history of the basin. The physical distribution and chemical composition of dolomite in the Trenton and Black River Formations are variable and suggest multiple episodes of dolomitization. The most extensive diagenetic alteration of both Trenton and Black River limestones has occurred in fracture-controlled hydrocarbon reservoirs. Within reservoirs several stages of dolomitization were followed by carbonate and sulfate cementation, and sulfide mineralization. Although the general patterns of reservoir alteration have been recognized for some time, possible causes of such alteration have not been adequately addressed. Several lines of evidence indicate that mineralization and hydrocarbon migration are related and occurred in the late Paleozoic, perhaps in response to compressional deformation caused by Appalachian tectonism. During such episodes, fluids were mobilized and channeled vertically through preexisting fracture zones. This fluid migration also served to drive maturing hydrocarbons out of Trenton–Black River source beds and into previously dolomitized, high-porosity intervals. This general mechanism could be applied to other fracture-related reservoirs in the Michigan Basin area based on the regional distribution of Mississippi Valley–type (MVT) reservoir alteration and compressional stress fabrics.