Structural control of the Cenozoic porphyry Cu-Mo, epithermal and skarn deposits and prospects, Central Tethyan belt, Lesser Caucasus

Abstract

The Cenozoic evolution of the central segment of the Tethyan metallogenic belt is dominated by the oblique convergence and final collision of Gondwana-derived terranes and the Arabian plate with Eurasia, which created a favorable setting for the formation of the highly mineralized Meghri-Ordubad pluton inthe southernmost Lesser Caucasus, in the Zangezur-Ordubad mining district. Paleostress reconstructions indicate anti-clockwise rotation from NE-oriented compression during the early and middle Eocene to NNW-oriented compression during the Pliocene. During the Eocene the N-S oriented faults are consistent with dextral strike-slip tectonics, correspond to synthetic faults and control the main porphyry Cu-Mo and epithermal deposits and prospects. The sinistral E-W oriented en- échelon faults correspond to antithetic faults. This strike-slip kinematics is consistent with the regional NE-oriented compression in the Zangezur-Ordubad district and concomitant with final subduction of the Neotethys along the Eurasian margin. Sinistral strike-slip kinematics along the E-W oriented faults resulted in clockwise rotation of the individual blocks of the Zangezur-Ordubad district. During the Oligocene and Miocene anti-clockwise rotation of the main paleostress compressional orientation resulted in reactivation of existing ore-controlling structures in a sinistral strike-slip tectonic regime, which is consistent with the re-orientation of the tectonic plate kinematics and re- organization of the Arabia-Eurasia collision