NEW EVIDENCE AND SOLUTION TO THE MADEN COMPLEX CONTROVERSY OF THE SOUTHEAST ANATOLIAN OROGENIC BELT (TURKEY)

The volcanosedimentary units of Late Mesozoic-Tertiary age that outcro p in the Southeast Anatolian orogenic belt are commonly referred to as the Maden complex. There is a long-lasting controversy over its defin ition, age, stratigraphic and structural position, and the origin, and thus, the orogenic evolution. To solve this problem, large strips acr oss the Southeast Anatolian orogenic belt have been studied extensivel y, and different rock groups which were regarded previously as the Mad en unit have been differentiated. Their major characteristics and diff erences have been identified. The Maden unit sensu stricto is here red efined as a volcanosedimentary succession of Middle Eocene age represe nting a short-lived back-are basin which reached the stage of an embry onic ocean. Presently, the Maden group occurs mainly within the lower nappe stack of the nappe zone of the Southeast Anatolian orogen. It re sts stratigraphically on an amalgamated nappe package consisting of th e different metamorphic tectonic units and, in turn, is overlain tecto nically by the upper nappe units.