Geologic and Geochemical Properties of the Mafic-Clastic Type Sariseki Volcanogenic Massive Sulfide Deposit, Central Pontides, Turkey

Abstract

The Sariseki mineralization has 4.3 million tonnes of 0.47wt% Cu and is one of the newly-discovered massive sulfide formations in the Central Pontides. Mineralization occurred within deep marine sediments interlayered with mafic sills and/or lavas of the cangaldag Metamorphic Complex. The lithologic units in the area of mineralization are metamorphosed under lower-greenschist facics conditions. The metamorphism transformed deep marine sediments into phyllites, whilst mafic sills and/or lava were transformed into chlorite-actinolite schist, chlorite schist and chlorite-epidote schist. The mineral paragenesis of the mineralization is represented by the following minerals in decreasing order of abundance; pyrite, chalcopyrite, sphalerite, and magnetite. Mineralization at different levels has three different textures; banded-disseminated, semi-massive and massive. The Sariseki mineralization has maximum Cu and Zn contents of 3.4 % Cu and 0.24 % Zn, in the Cu-dominant massive sulfide formations. Within the ore, silicified relict sections of wall rock lithology and grading in the mineralized sections indicates that mineralization might have developed by sub-seafloor replacement processes. Mineralization is dominantly formed within wall rock and metamorphic rocks with elastic origin, with no feeder zones in the lower sections of massive sulfide masses, irregular lenses in mineralization and a strata-bound structure. The mafic-clastic formation of Sariseki mineralization has similar features to Besshi-type Volcanogenic Massive Sulfide (VMS), an observation that is also supported by the results of ore and wall rock geochemistry.