14th Swiss Geoscience Meeting, Geneva 2016 Regional strike-slip tectonics and porphyry Cu-Mo and epithermal ore deposit formation during Cenozoic subduction to post-collisional evolution of the southernmost Lesser Caucasus, Tethyan belt Samvel Hovakimyan*,**, Robert Moritz*, Rodrik Tayan**, Rafael Melkonyan**, Marianna Harutyunyan** *Department of Earth Sciences, University of Geneva, Rue des Maraîchers 13, CH- 1205 Genève, Switzerland (
[email protected]) **Institute of Geological Sciences of the Armenian National Academy of Sciences, 0019 Yerevan, Republic of Armenia The oblique convergence and final collision of Gondwana-derived terranes and the Arabian plate with Eurasia during the Cenozoic created a favorable setting for the formation of the the highly mineralized Meghri-Ordubad composite pluton in the southernmost Lesser Caucasus, central segment of the Tethyan metallogenic belt. Regional strike-slip faults played a critical role in the control of the porphyry Cu-Mo and epithermal systems hosted by the Meghri-Ordubad pluton. Detailed structural field mapping, stereonet compilation of ore-bearing fractures and vein orientations, and paleostress reconstructions allow us to constrain the formation of ore deposits in the context of wrench fault tectonics. During Eocene subduction-related evolution of the region (Moritz et al. 2016), a NE-oriented compressional setting was favorable for dextral displacements along the two major, regional NNW-oriented Khustup-Giratakh and Salvard- Ordubad strike- slip faults (Fig.1). This resulted in the formation of a NS- oriented transrotational basin, known as the Central magma and ore- controlling zone (Tayan, 1998). It caused a horizontal clockwise rotation of blocks. The EW-oriented faults separating the blocks formed as en-échelon antithetic faults (Voghji, Meghrasar, Bughakyar, and Meghriget-Cav faults), and controlled the rotation of the blocks.