Geology of the Bozdag area, central Menderes massif, SW Turkey: Pan-African basement and Alpine deformation

Abstract

The Menderes massif consists of a Precambrian Core Series that preserves evidence for a polymetamorphic history and a Paleozoic/Mesozoic Cover Series that experienced only the Alpine tectonometamorphic evolution. Structural, petrographic, and geochronologic investigations in the central Menderes massif demonstrate that (a) part of the metamorphic and structural evolution of the Precambrian basement is older than the undeformed 551±1.4-Ma-old Birgi metagranite, and (b) inferred Alpine fabrics overprinting the Cover Series largely have the same attitudes as the old structures in the much older Core Series. The inferred Alpine fabrics include both contractional and extensional structures. Contraction under greenschist to amphibolite facies conditions resulted in the imbrication of the Core and Cover Series and generated an inverted metamorphic sequence by north-directed thrusting. During Alpine extension, most of the south-dipping thrust faults were reactivated as extensional shear zones under decreasing greenschist facies conditions.