Mineral chemistry of apatite in the Lar igneous complex, North of Zahedan

Moradi, Raheleh; Boomeri, Mohammad; Bagheri, Sasan

doi:10.29252/ijcm.27.2.281

Cited by 3 publications

(1 citation statement)

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“…The tectonic reworking of Sistan suture zone was governed by the splitting and successive closure of various lodges of the Neo-Tethyan ocean (Tirrul et al, 1983). It is highly reported that the Sistan suture zone is an immensely enriched metallogenic zone which hosts several Sb and Au-Sb ore deposits including Tuzgi and Shurchah (Moradi et al, 2012), Se dabeh (Eliaspour et al, 2010), Se dsang and Dargiaban (Boomeri, 2014), Baout (Mojadadi Moghadam and Boomeri, 2021) and Lakhshak (Fig. 2; IMPASCO, 2016; Mazloom et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Genesis of the Lakhshak orogenic Au–Sb deposit, SE Iran: insights from geology, microthermometry and stable isotope geochemistry

Rajabpour,

Niroomand,

Dehkordi

et al. 2024

Preprint

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The Lakhshak Au–Sb deposit in the SE Iran, is closely associated with Eocene calc–schist and quartz schist rocks intruded by Oligocene dikes and mylonitic granitoid. The main mineralization is characterized by a NE–SW shear zone structure and hydrothermal alterations have mainly developed in the contact zones of granitoid and calc–schist units. Quartz veins and veinlets are associated with Au and Sb–bearing minerals consisting of pyrite, arsenopyrite, stibnite, pyrrhotite, chalcopyrite, sphalerite, gold and electrum. The ore genesis, metallogenic processes, and the origin of ore fluids in the Lakhshak deposit are unknown, hence we report for the first time the geological, petrographic, microthermometry of fluid inclusions, Raman spectroscopy and sulfur and oxygen isotopes studies. In this study, four types of fluid inclusion assemblages were recognized in the mineralized quartz veins. The results of fluid inclusion microthermometric measurments yield homogenization temperatures of two–phase LV (type III) and ternary carbonic–aqueous phase (LCO2 + LH2 O + VCO2; type IV) fluid inclusions vary between 200 to 280°C and 300 to 330°C, whereas their salinity range from 9 to 11% and 8 to 13% wt. % NaCl, respectively. This implies that gold precipitation is derived from low–temperature and low–salinity ore fluids. The calculated δ18Ofluid values of quartz vary from 7.5 to 9.8‰, implying that the ore fluids may have a metamorphic origin that reacted repeatedly with the volcanic rocks along the conduits as well as the granitoid units adjacent to the ores and subsequently experienced sporadic equilibrium in oxygen fractionation during formation. Therefore, due to the significant oxygen isotopic exchange in the fluid–rock reaction, the metamorphic fluids show the isotopic properties of specific fluids of magmatic origin. Moreover, the δ34S values of pyrite (3.0 to 4.1‰) and stibnite (–0.9 to 0.8‰) from the main satge of mineralization show a magmatic origin for sulfur. Accordingly, it is suggested that the mixing and dilution of metamorphic fluids with meteoric water plausibly had a substantial effect on the evolution of ore–forming system at Lakhshak, similar to orogenic gold deposits worldwide.

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Section: Introductionmentioning

confidence: 99%