Miogeoclines and suspect terranes of the Caledonian–Appalachian Orogen: tectonic patterns in the North Atlantic region
The Caledonian–Appalachian Orogen was formed by the closing of a Paleozoic Iapetus Ocean. The continental margins of Iapetus are identified in the deformed early Paleozoic miogeoclines of the Caledonian–Appalachian Orogen. Ophiolitic vestiges of Iapetus, its oceanic plateaus, microcontinents, and volcanic arcs are Caledonian–Appalachian suspect terranes. These were assembled in interior parts of the orogen and locally they were emplaced structurally upon the adjacent miogeoclines.The modern North Atlantic Ocean opened along an axis that traversed the Paleozoic orogen longitudinally. Its opening dispersed the elements of the Paleozoic orogen and led to the present arrangement of disjunct Paleozoic miogeoclines and suspect terranes throughout the North Atlantic borderlands.The western or North American margin of Iapetus is represented by the miogeoclines along the west flank of the North American Appalachians and Caledonides of east Greenland. A small North American miogeoclinal segment occurs in the Britis...