Writers : Nouri Asl, Farzane; Shamanian, Gholam Hossein; Shafiei, Behnam; Jafari Zanglanlou, Mohammad
Refference : 27th Symposium on geosciences and the 13th symposium on geological society of Iran-Tehran
Publishing Year : 1388

Abstract :

The Arghash quartz-antimony veins have been occurred within a sequence of Eocene volcanic rocks and Oligocene intrusions. Quartz, illite-smectite, K feldspar (adularia), chlorite, epidote and pyrite are the main hydrothermal minerals occurring around the veins at >150 °C. Mineralization is mostly restricted to faults and fractures, taking place as irregular veins and veinlets and hydrothermal breccias. The mineralogy of the veins is comparatively simple. The primary antimony-bearing mineral is stibnite. Other sulfides have been found in association with stibnite are pyrite, chalcopyrite and sphalerite. Field and microscopic evidences indicate a simple order of ore deposition started by the microcrystalline quartz and followed by the deposition of euhedral to subhedral pyrites. Negligible amounts of chalcopyrite and sphalerite probably have been deposited with pyrite ending in a low temperature condition. Deposition of fine grain crystalline quartz and stibnite was happened at the last stage of paragenetic sequence which followed by the deposition of framboidal pyrites. Valentinite and secondary iron oxy-hydroxides are the youngest products formed by secondary surficial processes. The mineralogic, alteration and geochemical characteristics of the studied area and comparison with epithermal ore deposits indicate that the Arghash quartz-antimony veins represent an epithermal system of the low-sulfidation type. This data suggests that boiling and cooling were the main ore deposition processes in the area.

Subject List : Antimony, Altration, Mineralization