The metamorphic evolution of the high-pressure Kechros complex in East Rhodope (NE Greece): Implications from Na-Al-rich leucocratic rocks within antigorite serpentinites

The exact ages of HP metamorphism in the Kechros Complex are not well constrained, however, a Rb-Sr age of 37 Ma from a neighboring orthogneiss records a stage of exhumation that may be contemporaneous with the Eocene HP metamorphism (49-55 Ma; i.e., recorded in the Nestos Shear Zone of Central Rhodope). We interpret this to be the result of the eventual closure of the Axios/Vardar Ocean and subsequent subduction of the Apulian continental crust (a promontory of the Africa continent) under the southern margin of the European continent in the late Cretaceous and early Tertiary.