Doğu Karadeniz bölgesi volkanojenik masif sülfid yataklarının tip özelliklerinin belirlenmesi

MUSTAFA KEMAL REVAN

Doğu Karadeniz bölgesi volkanojenik masif sülfid yataklarının tip özelliklerinin belirlenmesi

Thesis Type: Doctorate

Institution Of The Thesis: Hacettepe Üniversitesi, Fen Bilimleri Enstitüsü, Jeoloji Mühendisliği A.B.D., Turkey

Approval Date: 2010

Thesis Language: Turkish

Student: MUSTAFA KEMAL REVAN

Principal Supervisor (For Co-Supervisor Theses): YURDAL GENÇ

Open Archive Collection: AVESIS Open Access Collection

Abstract:

Geological processes that control the formation environment and conditions of the volcanic-associated massive sulfide (VMS) deposits representing important metal resources as a class are still under immense research. In order to better understand the processes controling the formation environments and conditions of the deposits in Turkey, an attempt has been commenced to determine the common properties of the deposits and to develop new criteria in search of similar deposits with the detailed geological works conducted on the six VMS type deposits in the Eastern Black Sea Region. The volcanic-associated massive sulfide (VMS) deposits of the Eastern Black Sea Region were formed within bimodal (rhyolite/basalt) volcanic sequences in a single geological period (Turonian-Maastrichtian) within a metallogenic belt of around 500x100 km. The majority of the Pontide deposits formed within volcanic-dominated sequences in deep seawater setting. It is observed that the rocks in this environment dominated by the Late Cretaceous aged volcanic rocks are generally altered lava flows, lava breccia and hyaloclastites. Sedimentary rocks consist of fossiliferous limestones, mudstones and hydrothermal sediments (or exhalites). Deposits related to tectonic structures were formed in the vent area of rhyolitic/dacitic domes. Quartz-sericite-kaolinite and chlorite alteration are the main alteration types associated with the deposits. Fragments of the mineralized hydrothermal chimneys defined in the massive ores of the deposits and fossil fauna traces (tube worm) are the most important evidences indicating that the concerned Eastern Pontide deposits were formed on the paleo-deep sea floor. VMS deposits are Cu-Zn rich deposits formed both on the sea floor and sub-sea floor setting in terms of composition and type. The sub-sea floor ores are in the shape of stockwork, disseminated and massive veins. The sea floor ores consist of massive, proximal (coarse-fine fragments) and distal reworked (sulfide sandstone and intercalated with sediments) facies. The deposits can be classified into four groups based on their metal content: Cu-Zn, Cu-Zn-(Pb-Au-Ag), Cu and Cu-(Au-Ag). The initial properties of the the ores of the VMS deposits of the Eastern Black Sea region are well preserved in terms of texture (fragmental/clastic ore) and components (hydrothermal chimneys, fossil fauna). Pontide type deposits have comparable properties with the well preserved Urals (Ural type) and Hokuroko (Kuroko type) districts.