Abstract:

The Susurluk skarn deposit developed at the contacts of the Çataldağ Granitoid and Mesozoic carbonate rocks is represented by endo and exoskarn (proximal zone, distal zone and vein skarn) zones. The endoskarn zone which occurs in a limited area is characterized by clinopyroxene, plagioclase, sphene, orthoclase and quartz minerals. The exoskarn zone is composed mainly of clinopyroxene, vesuvianite, wollastonite and some accessory minerals such as calcite, quartz, plagioclase, orthoclase, scapolite, biotite, muscovite, sphene and chlorite and ore minerals of scheelite, chalcopyrite and bornite. The presence of anhydrous minerals such as garnet and clinopyroxene is indicative of prograde stage, and the absence of hydrous minerals such as epidote, amphibole and biotite indicates that retrograde stage was not developed. Microthermometric data on exoskarn zone reveal that boiling at temperatures of 587°-592°C took place at the first stage of skarnization. Solutions of the first stage in which scheelite mineralization occurred are characterized by homogenization temperatures of 587 to 600°C and salinity range of 11-16 wt% NaCI equivalent. At the second stage of skarnization, homogenization temperatures and salinities were recorded as 371 to 600°C and 36 to >70 wt% NaCI equivalent, respectively. High salinity values are attributed to boiling phenomenon. The Te values of fluid inclusions may indicate a solution composition of CaCl2+NaCl+KCl+H2O and the significant amount of carbonic additions to the system, CO2 (Te: -66 to -58°C) and CH4 (Te: -188 to -178°C). The Susurluk skarn deposit which entirely shows shallow skarn system characterized might have been formed at a pressure of around 1 kbar.

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