Late Alpine Extensional Stage of the Central Rhodopian Core Complex and Related Acid Magmatism (Madan Dome, Bulgaria) - Isotope and Geochronological Data

摘要

In order to determine relative and absolute timing of metamorphic and magmatic evolution of the Madan core complex (Central Rhodopes, Bulgaria) and ore mineralisation are analyzed gneisses from lower and upper plate (Ar-Ar on Bt and Rb-Sr - WR, Bt and Ap) and rhyolite dikes which show crosscutting relationships with detachment and Paleogene sediments and predate ore mineralisation (U-Pb and Hf on single zircons and Nd, Rb-Sr - WR analysis). Cooling age of the gneisses from upper and lower plate is similar within the analytical error - 35Ma. Age of rhyolite dikes is 32+-0.41Ma. Initial ~(87)Sr/~(86)Sr ratio, ε_(Nd) and ε_(Hf) of the rhyolite indicate young crust + mantle input as a source of magma generation.