Browsing by Author "Baran, Cuneyt"

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Geologic and Geochemical Properties of the Mafic-Clastic Type Sariseki Volcanogenic Massive Sulfide Deposit, Central Pontides, Turkey
(E Schweizerbartsche verlagsbuchhandlung, 2021) Baran, Cuneyt; Yesilova, Cetin; Gunay, Kurtulus
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.
Geology, Geochemistry and Re-Os Geochronology of the Jurassic Zeybek Volcanogenic Massive Sulfide Deposit (Central Pontides, Turkey)
(Elsevier, 2019) Gunay, Kurtulus; Donmez, Cahit; Oyan, Vural; Baran, Cuneyt; Ciftci, Emin; Parlak, Osman; Ozkumus, Serkan
Located in the north of Anatolia, the Pontide Orogenic Belt hosts Turkey's most important volcanogenic massive sulfide (VMS) deposits. Studies completed in the last ten years have discovered new massive sulfide deposits in the Central Pontide zone. The Zeybek VMS deposit is one of these newly-discovered deposits found in the Central Pontides. This deposit is associated with the Cangaldag Metamorphic Complex occurring as east-west-striking tectonic slices. The Cangaldag Metamorphic Complex is an allochthonous mass of metavolcanic, metavolcanidastic and metaclastic rocks in the form of imbricated tectonic slices. Zeybek massive sulfide deposit is located within metaclastic rocks intercalated with mafic sills or lava flows in this complex. The major ore mineral paragenesis in the Zeybek VMS deposit comprises pyrite, chalcopyrite and sphalerite, with lower amounts of bornite, covelline, chalcocite and magnetite. With thirty thousand meters of drilling in the mineralized area, 20 million ton resources with 0.32 wt% Cu were determined. According to the wall-rock mineralization relationships, mineralization style and ore geochemistry of the Zeybek VMS mineralization, it is similar to a mafic-siliciclastic type volcanogenic massive sulfide formation. Re-Os geochronologic studies of chalcopyrites from the Cu-rich massive ore samples obtained a 178 +/- 2.2 Ma (MSWD: 4.1) Re-187/Os-188 against Os-187/Os-188 isochron. Geochemical and isotopical age data associated with the Zeybek VMS deposit indicate that the mineralization occurred in an arc-back arc tectonic environment, which developed in Middle Jurassic age intra-ocean as a result of the closure of north-ward subduction that resulted the closure of the Tethys ocean.