The Upper Devonian sequence in the Michigan Basin is a westward extension of coeval cyclical facies of the Catskill deltaic complex in the Appalachian basin. Both basins and the intervening Findlay arch express the tectonic and sedimentational effects of foreland compression and isostatic compensation produced by the Acadian orogeny. The Late Devonian Michigan Basin formed as one of several local deeps within the long Eastern Interior seaway that separated the North American craton, backboned by the Transcontinental arch, on the west from the Old Red continent, Avalon terrane (microplate), and possibly northwest Africa on the east. Basin development began in the late Middle Devonian (late Givetian varcus Zone) with subsidence of a shallow-water carbonate platform formed by rocks of the Traverse Group. Subsidence was contemporaneous with Taghanic onlap of the North American craton. During subsidence, a thin transitional sequence of increasingly deeper water limestones separated by hardgrounds was deposited in the incipient Michigan Basin during the latest Givetian to earliest Frasnian disparilis to falsiovalis Zones. Deposition of this sequence culminated during the early Frasnian transitans Zone with a calcareous mudstone bed at the top of the Squaw Bay Limestone. Subsidence was followed by a 12-m.y.-long Late Devonian episode of slow, hemipelagic, basinal sedimentation of organic black muds that formed the Antrim Shale, interrupted basinwide only by deposition of its prodeltaic Paxton Member. Westward, the basinal Antrim black muds intertongued with greenish gray, deltaic and prodeltaic muds of an eastward-prograding delta platform formed by the Ellsworth Shale. Basinal black shale deposition ceased in latest Devonian (late Famennian Lower praesulcata Zone) time, when the Bedford deltaic complex prograded westward, completely filling the Antrim Basin and even covering part of the older Ellsworth deltaic complex on the west. As sea level was lowered eustatically near the end of the Devonian, the regressive Berea Sandstone terminated deltaic deposition. After an Early Mississippian erosional episode, widespread deposition of the unconformably overlying Lower Mississippian Sunbury Shale began during the next transgression, associated with a major eustatic rise in the Lower crenulata Zone.