Ore forming fluids in the Allchar Au-Sb-As-Tl deposit, FYR Macedonia

The Allchar Au-Sb-As-Tl mineral deposit is a Carlin-type mineralization with a zonal distribu-tion of mineral parageneses and alterations. The zonation is a result of a spatial distribution of ore-forming fluids with different thermal and chemical characteristics as proven by a fluid inclusion study. Three zones are distinguished: 1. a southern Au-Sb-As zone, 2. a central zone, which hosts a Au-Sb-As-Tl-Hg mineralization, and 3. a northern As-Tl zone. Homogenization temperature and sa-linity decrease steadily from the southern to the northern zone of the deposit due to cooling and di-lution of the fluids.