The Lower to Middle Proterozoic Sakoli fold belt in Central India forms a triangular belt with significant mineralization of strategic minerals. The Sakoli fold belt comprises metasediments, felsic and mafic volcanics with metabasalts bounded by the gneissic-migmatitic terrain. The last pulses of granitic activity in the form of quartz lenses intrude the metasediments and are associated with tungsten mineralization. The metasediments are intruded by the quartz veins and tourmaline breccias trending 60°N to 65°E and 60°S to 65°W and are parallel to the regional structural foliations. The tungsten mineralization in this area is restricted to tourmaline-quartz mica greisens and quartz veins. The NE-SW trending foliated contact zones of chlorite mica schist and porphyritic granite/gneisses have served as easy channels for the mineralizing vapours and solutions to percolate, which formed ore bearing greisens and quartz veins. This mineralization is erratic and manifested by sparse and sporadic disseminations of wolframite and scheelite associated with minor amount of molybdenite and chalcopyrite. The fluid inclusion microthermometry on mineralized quartz veins and quartz-tourmaline veins reveals the existence of a metamorphogenic aqueous- gaseous (H₂O-CO₂+NaCl) fluid that underwent phase separation and gave rise to gaseous (CO₂) inclusion. The salinity of tungsten mineralizations varies from low to high (1.32 wt.% to 40.44 wt.% NaCl eq.). The estimated P-T range of tungsten mineralization varies from 1.2 to 2.2 kbar at 280 to 390 °C. Raman spectroscopy reveals that the fluid inclusions mainly contain H₂O and CO₂ with rarely H₂S and CH₄. Stable isotopic data reveal that the sulfur isotope fractions from the deposits δ³⁴S ranging from +3.1‰ to +3.35‰, suggesting the deep crustal source for the sulfur, which can be further interpreted as a single (magmatic) supply of sulfur during magmatic-hydrothermal mineralization. The studies reveal the presence of chlorides such as FeCl₂/MgCl₂ and CaCl₂, indicating the involvement of chloride complexes in transportation of tungsten to the fluid system and the evolution of the ore-forming fluids by mixing or immiscibility of high-temperature, high-salinity magmatic fluids and low-temperature, low-salinity fluids in hydrothermal system, and also representing magmatic-hydrothermal interactions contributed wolframite and scheelite with minor amount of molybdenite and chalcopyrite.

中文翻译：

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印度中部萨科利褶皱带阿加冈地区钨矿化的流体包裹体特征

印度中部的中元古代至中元古代Sakoli褶皱带形成三角形带，其中战略性矿物质大量矿化。Sakoli褶皱带包括变质沉积，长英质和镁铁质火山岩，其玄武岩由片麻质-玛格达菲地形限定。石英晶状体的花岗岩活动的最后脉冲侵入了沉积物，并与钨矿化有关。变质沉积物被石英脉和电气石角砾岩侵入，其趋势为北纬60°N至65°E和北纬60°S至65°W，并与区域构造叶面平行。该地区的钨矿化仅限于电气石，石英云母和石英脉。绿泥石云母片岩和斑状花岗岩/片麻岩的NE-SW趋向叶状接触区已成为矿化蒸汽和溶液渗滤的便捷通道，形成了含矿砂岩和石英脉。这种矿化作用是不稳定的，其特征是黑钨矿和白钨矿的稀疏和零星分布以及少量的辉钼矿和黄铜矿。矿化石英脉和石英-电气石脉上的流体包裹体微量热法揭示了存在变质的水-气态（H₂ O-CO ₂ + NaCl）流体，经过相分离并产生气态（CO ₂）夹杂物。钨矿化的盐度从低到高不等（NaCl当量为1.32 wt。％至40.44 wt。％）。钨矿化的估计PT范围在280至390°C时为1.2至2.2 kbar。拉曼光谱表明，流体包裹体主要含有H ₂ O和CO ₂，很少含有H ₂ S和CH ₄。稳定同位素数据表明，从沉积物的硫同位素的级分δ ³⁴S的范围为+ 3.1‰至+ 3.35‰，表明硫的深层地壳来源，可以进一步解释为岩浆热液成矿过程中的单一（岩浆）硫供应。研究表明，存在氯化物，例如FeCl ₂ / MgCl ₂和CaCl ₂，表明氯化物络合物参与了钨向流体系统的运输以及由于高温的混合或不混溶而形成的成矿流体，热液系统中的高盐度岩浆流体和低温，低盐度流体，也代表了岩浆-水热相互作用，促成黑钨矿和白钨矿以及少量的辉钼矿和黄铜矿。