A New Porphyry Mo Mineralization at Aisymi-Leptokarya, Southeastern Rhodope, NE Greece: Mineralogical and Geochemical Constraints

A new porphyry Mo mineralization has been discovered at Aisymi-Leptokarya, in the southern periphery of the Byala reka-Kechros metamorphic dome, SE Rhodope metallogenic zone. The study area is dominated by an Oligocene felsic dyke complex, which hosts the porphyry Mo mineralization and intrudes Upper Eocene sandstones-marls and the Leptokarya monzodiorite pluton. The Aisymi-Leptokaria felsic dyke complex display a rhyodacitic to dacitic composition with post-collisional affinities. The porphyry Mo mineralization occurs in the form of porphyry-type quartz stockworks in the felsic dyke complex associated with potassic alteration characterized by hydrothermal K-feldspar. The main ore minerals consist mainly of pyrite, molybdenite, magnetite, bismuthinite, kesterite, galena and sphalerite within both the stockworks and the rock matrix. Bulk ore analysis indicated an enrichment in Mo (up to 215 ppm), Se (up to 29 ppm), Bi (up to 8 ppm) and Sn (up to 14 ppm) in the quartz veinlets. Late-stage, NE- and NW-trending milky quartz intermediatesulfidation epithermal veins with base metals crosscut previous vein generations and are characterized by Ag, Sn and Te anomalies. The studied porphyry Mo prospect has affinities to the “arc-related” class of porphyry molybdenum deposits. The Aisymi-Leptokarya porphyry Mo prospect represents a more evolved and fractionated system compared to earlier granodiorite- and monzodiorite-related porphyry events present in the western Thrace area. A comparison of the Aisymi- Leptokarya porphyry Mo prospect with the microgranite- and rhyolite-hosted porphyry- and epithermal deposits at Maronia and St Philippos respectively, suggest that acid magmatism played a major role in the metal endowment of southern Rhodope area.