Türkiye Jeoloji Bülteni

Mineralogy of the Lahanos Deposit a Kuroko-Type Volcanogenic Massive Sulfide Deposit from the Eastern Pontides (Giresun-NE Turkey)

Abstract: The Lahanos volcanogenic massive sulfide (VMS) deposit is situated in the westernpart of the easternPontide tectonic belt. The deposit is hosted predominantly by a late Cretaceous felsic volcanic complex and ismined mainly for copper and zinc. The deposit is essentially stratabound, with characteristics of both Cu-Znand Cu-Zn-Pb-type stratiform VMS deposits. The deposit consists mainly of yellov ore (oko) and a zone thatcan be considered as semi-blackore.Ore mineralization occurs mainly as massive ore, and to lesser extent as disseminated andstochvorkore. Major ore minerals include pyrite, chalcopyrite, sphalerite, galena, tetrahedrite/tennantite, bornite, andminor to trace covellite, marcasite, chalcocite, and digenite. Gangue minerals are chiefly auartz and baritewith minor calcite and dolomite. The deposit has aparagenetic seguence of pyrite (I, II) - chalcopyrite (I)sphalerite - galena tetrahedrite/tennantite digenite chalcosite pyrite (III) - chalcopyrite (II) bornite -covellite. A great variety of intimate intergrowth ore textures including replacement, colloform, disseminated,and fragmental textures prevail throughout the deposit.The fıne-grained nature of the Lahanos ore presents diffıculties in benefıciation. Sphalerite, as inother VMS deposits of the region, is notably Fe-poor (< 0.7 wt. %).