Occurrence of Halotrichite in Bidakhvaid felspar-bearing alluvium, SW of Shirkuh batholith, Yazd

The Bidakhavid mine is located on the western margin of the Shirkouh Batholith in the Central Iran and as a part of Urumieh-Dokhtar magmatic belt. This mine is the result of alteration of quaternary alluvial deposits. The main unit of the Bidakhavid mine is the iron oxide cement-semi-hardened alluvial-abrasive sediments with main minerals, including quartz, biotite, K- feldspar, altered plagioclase and clay minerals. Significant geological aspects are the emission of sulfur gases and the deposition of natural sulfur in surface of Quaternary alluvial deposits. The presence of efflorsence minerals such as halotrichite, confirm a fumarole region and the release of volcanic sulfid gases associated with young volcanism in the Dehshir fault zone. Iron sulfate efflorsence minerals are produced by pyrite oxidation and the formation of acidic environments on the surface of the groundwater table. The occurrence of this highly acidic environment has led to the occurrence of alteration minerals such as pyrite, sericite, rectorite, illite and jarosite.