Stable isotope (O, H and C) studies and the origin of the mineralising fluid in the wein type antimony deposits in the Turhal area, Turkey

Abstract

The Turhal area, located in the Northern Central Turkey, is one of the richest antimony provinces in Turkey. There are four different styles of sitibnite mineralisation and the vein type deposits are the most widespread ones. This study gives stable isotopes evidence for the origin of the water in the mineralising fluid of this style of mineralisation. These are put into the context of the results of the earlier basic ore geology, ore microscopy, geochemistry, fluid inclusion and sulfur isotope studies. $\delta^{18}O$ values of quartz are in a very narrow range of +24.1 to +25.5 %o SMOW and reflects the metasedimentary host rocks in the area. $\delta^{18}O$ values of water calculated from these values, are in the range of +2.1 to +3.5 %o SMOW. In addition, $\delta D$ values of the inclusion fluid are dispersed between -69.8 to -31.9 %o SMOW and $\delta^{13}C$ values of CO2 in the inclusion fluid are in the range of -4.8 to +0.5 %o PDB. These $\delta^{18}O$ and $\delta D$ values suggest formation waters, possibly originating from the deep circulated meteoric water, for the origin of the water in the mineralising fluid. $\delta^{13}C$ values of CO2 in the inclusion fluids suggest that mineralising fluids must have circulated through the marin carbonate bearing units; such as the calcareous quartzite bands in Turhal Metamorphics or the Buzluk Limestones in the area. According to these evidence, it may be said that the stibnite veins in Turhal areas were formed by the deep circulated meteoric water, which dissolved the sulfur and antimony either from the earlier formed stibnite deposits or from the metabasitic host rocks in the area, transported and deposited its content through the permeable fault zones. Deposition was caused by the drop in temperature and increase in pH, at the contact with the calcareous quartzite bands in Turhal metamorphics.

The Turhal area, located in the Northern Central Turkey, is one of the richest antimony provinces in Turkey. There are four different styles of sitibnite mineralisation and the vein type deposits are the most widespread ones. This study gives stable isotopes evidence for the origin of the water in the mineralising fluid of this style of mineralisation. These are put into the context of the results of the earlier basic ore geology, ore microscopy, geochemistry, fluid inclusion and sulfur isotope studies. $\delta^{18}O$ values of quartz are in a very narrow range of +24.1 to +25.5 %o SMOW and reflects the metasedimentary host rocks in the area. $\delta^{18}O$ values of water calculated from these values, are in the range of +2.1 to +3.5 %o SMOW. In addition, $\delta D$ values of the inclusion fluid are dispersed between -69.8 to -31.9 %o SMOW and $\delta^{13}C$ values of CO2 in the inclusion fluid are in the range of -4.8 to +0.5 %o PDB. These $\delta^{18}O$ and $\delta D$ values suggest formation waters, possibly originating from the deep circulated meteoric water, for the origin of the water in the mineralising fluid. $\delta^{13}C$ values of CO2 in the inclusion fluids suggest that mineralising fluids must have circulated through the marin carbonate bearing units; such as the calcareous quartzite bands in Turhal Metamorphics or the Buzluk Limestones in the area. According to these evidence, it may be said that the stibnite veins in Turhal areas were formed by the deep circulated meteoric water, which dissolved the sulfur and antimony either from the earlier formed stibnite deposits or from the metabasitic host rocks in the area, transported and deposited its content through the permeable fault zones. Deposition was caused by the drop in temperature and increase in pH, at the contact with the calcareous quartzite bands in Turhal metamorphics.