Geology of Pb-Zn-(Ag) ore deposits related to Eğrigöz and Koyunoba plutons

The I-type Eğrigöz and Koyunoba Plutons are the examples of Oligo-Miocene, post-colisional magmatism in the Inner Western Anatolia. Karakoca and Sudöşeği deposits hosted by Koyunoba and Eğrigöz respectively, are the subject of this study. Mineralization in Karakoca occurs in a 1,5 km long vein system striking NW-SE and dipping 50-80SW, with thickness up to 20-30 m. Sudöşeği mineralization consists of a single vein, striking ENE-WSW and dipping 65-70N with thichness 5-10m and 10- 15m long in the outcrop. Hypogene stage in Karakoca is distinguished into 3 phases. Galena and pyrite are formed in the first phase, while abondant sphalerite and chalcopyrite present in the second stage. The last stage is dominated by chalcopyrite with some sphalerite and galena. Bornite?, chalcocite /covellite, hematite, digenite and sericite replaced the.ore minerals in the supergene stage. Sudöşeği hypogene stage is distinguished into two phases. Galena and pyrite are syn-genetic in the first stage, whereas sphalerite and chalcopyrite are present in the second stage. Ore minerals are replaced by chalcosine/covellite, goethite and cerusite in the supergene stage. The homogenization temperature (Th) of quartz samples in Karakoca are in between 209-363 ° C (n = 87, avg 286,58), salinity in between 0.5-9 (n = 82 avg 4.83) % NaCl (equivalent). Th of sphalerites are in between 251-300 oC (n = 19, avg: 283 oC), salinity (NaCleqv); between in 4.5-6.6 (n = 11, avg: 5.82). The quartz samples of Sudöşeği have showed homogenization temperatures (Th) in between 211-349 °C (n=51, avg. 269.53), salinity between 0.2-15.5 (n=35 avg. 4.72) %NaCl(equivalent).The δ34S isotopes in Karakoca are in range of -2.64, -1.6, while in between -6.3 and -0.28 for Sudöşeği, indicating the source of sulphur is magmatic for both deposits. The FeS mole ratio of sphalerites in Karakoca ad Sudöşeği are in between 3.15 and 8.4, indicating the mineralization have intermediate-sulphidation