Alpine high pressure evolution of the eastern Bitlis complex, SE Turkey

Abstract

AbstractThe Bitlis complex, SE Anatolia, constitutes a crystalline complex derived from the north of the Arabian Plate, accreted to the South Armenian block. Metamorphic studies in the cover sequences of the Bitlis complex allow constraining the thermal evolution of the massif by metamorphic index minerals. A regionally distributed low temperature-high pressure (LT-HP) metamorphic evolution is documented by glaucophane, relics of carpholite in chloritoid-bearing schists and pseudomorphs after aragonite in marbles. The metamorphic age of these HP assemblages is constrained by Ar isotope dating as 74±2 Ma. This indicates that (i) the Bitlis complex represents a terrane detached from the Arabian indenter that was subducted and stacked to form a nappe complex during the closure of the Neo-Tethys and (ii) that during Late Cretaceous to Cenozoic evolution the Bitlis complex never underwent temperatures over 450 °C. The consequences of the metamorphic evolution of the Bitlis complex (a cold continental block within a hot environment) for the Eastern Anatolian plateau are complied in a crustal section.