Geology, mineralogy and the Pb, S isotope study of the Kalkim Pb-Zn +/- Cu deposits, Biga Peninsula, NW Turkey
Yükleniyor...
Dosyalar
Tarih
2013
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ceska Geologicka Spolecnost
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Three main Pb-Zn +/- Cu deposits (Handeresi, Bagirkacdere, and Firincikdere) occur south of Kalkim in the southeastern part of the Biga Peninsula (NW Turkey). Massive and disseminated Pb-Zn mineralization consists of ore veins in fault zones and replacement bodies in carbonate layers in metamorphic rocks. Garnet (similar to Ad(64)Gr(36)), pyroxene (similar to Di(30)Hd(45)Jo(25)), epidote and rare tremolite-actinolite are found as gangue minerals in ore zones. The garnets often show oscillatory zoning and correspond to grossular, andradite and grandite in composition. The pyroxene minerals are manganiferous hedenbergite, johannsenite and diopside. The Mn/Fe ratios of the pyroxene range between 0.3 and 0.9 (mean 0.5). Such compositions of the garnet and pyroxene and gangue assemblages are typical of distal Pb-Zn skarns. The ore minerals are pyrite, sphalerite, chalcopyrite, galena, magnetite, hematite, and arsenopyrite. The mean lead isotopic values for galena are Pb-206/Pb-204 similar to 18.760, Pb-207/Pb-204 similar to 15.689, and Pb-208/Pb-204 similar to 38.935. The comparison of these isotope data with the host-rock samples (graphite schist, andesite and granodiorite) indicates that part of lead could have been leached from the schists. The delta S-34(VCDT) values for galena, sphalerite, and chalcopyrite are -1.1 to + 1.5 % (mean: -0.2 %), 0.7 to + 2.1 % (mean: + 0.7 %), and -0.6 to + 1.5 % (mean: + 0.4 %), respectively. Lead isotope data and delta S-34(VCDT) values close to 0 % indicate the formation of ores by magmatic processes. Taken together, the Oligo-Miocene magmatism in the area is taken responsible for the polymetallic mineralization. However, the metamorphic rocks and their protoliths may have contributed part of the lead.
Açıklama
Anahtar Kelimeler
Lead-Zinc Mineralization, Skarn, Sulphur and Lead Isotopes, Handeresi, Bagirkacdere, Firincikdere
Kaynak
Journal of Geosciences
WoS Q Değeri
N/A
Scopus Q Değeri
Q3
Cilt
58
Sayı
4
