This study describes textures and mineral chemistry of magnetite-ilmenite-bearing pods/pockets in mineralogically diverse feldspathic schist near Pathargora in the Singhbhum Shear Zone, eastern India. The textural and geochemical characteristics of the magnetite-ilmenite assemblage are the results of a protracted geological history involving magmatic crystallization and oxidation-exsolution of titanomagnetite, deformation-induced recrystallization and textural re-equilibration and hydrothermal fluid-induced hematitization of magmatic magnetite. The magnetite grains contain characteristic trellis and sandwich ilmenite lamella, which are interpreted to be the products of oxidation-exsolution of ulvöspinel component of magnetite-ulvöspinel solid solution. The exsolution process was accompanied by preferential partitioning of spinel elements such as Cr, Al and V in magnetite and Ti, Mn, Mg, HFS elements (Nb, Ta), transition elements (Sc, Co, Cu and Zn) and granitophile elements (Mo, Sn and W) in ilmenite. The deformed sandwich lamella is locally recrystallized and transformed into granular ilmenite close to fractures, micro-shear planes and magnetite grain boundaries. Coarse granules of ilmenite, within or associated with magnetite, are of two textural types: one invariably contains Fe-rich exsolved phase and may be of magmatic origin, while the other mostly formed by strain-induced, fluid-mediated expulsion (from the interior of magnetite to its boundary) and dynamic recrystallization of existing ilmenite lamella in magnetite, and dynamic recrystallization of primary ilmenite containing Fe-rich exsolved phases. Magnetite is variably hematitized. The highly porous nature and trace element geochemistry of hematite and mass-balance calculations suggest the hematitization was mostly redox-independent and was caused by infiltration of metal-rich, reduced and acidic fluid. The hematitization process was associated with significant enrichment and immobilization of U, Th, Pb, REEs, Cu, Mo and W and depletion of Ni, Cr, V in hematite.

这项研究描述了印度东部Singhbhum剪切带Pathargora附近矿物学多样的长石片岩中含磁铁矿-钛铁矿的豆荚/袋的质地和矿物化学。磁铁矿-钛铁矿组合的组织结构和地球化学特征是长期的地质历史的结果，涉及到钛磁铁矿的岩浆结晶和氧化析出，形变诱导的再结晶和组织的再平衡以及水热流体诱导的岩浆磁铁矿的赤铁矿化。磁铁矿晶粒含有特征格状和夹层钛铁矿薄层，这被解释为磁铁矿-ulsöspinel固溶体中ulvöspinel组分的氧化-溶解的产物。析出过程中伴随着尖晶石元素（例如Cr，Al和V）在磁铁矿中的优先分配，以及Ti，Mn，Mg，HFS元素（Nb，Ta），过渡元素（Sc，Co，Cu和Zn）和嗜亲花岗岩元素（钛铁矿中的Mo，Sn和W）。变形后的夹层薄板在局部重结晶，并转变成接近裂​​缝，微剪切平面和磁铁矿晶界的粒状钛铁矿。在磁铁矿内部或与磁铁矿相关的粗大的钛铁矿颗粒有两种组织类型：一种总是含有富铁的溶解相，并且可能是岩浆成因的，而另一种主要是由应变诱导的，流体介导的驱除作用（从内部）形成的。磁铁矿的边界）和磁铁矿中现有钛铁矿薄片的动态再结晶，富钛溶解相的钛铁矿的动态重结晶。磁铁矿的变质是赤铁矿。赤铁矿的高度多孔性质和微量元素地球化学以及质量平衡计算表明，赤铁矿化主要与氧化还原无关，并且是由富金属，还原性和酸性流体的渗透引起的。赤铁矿的赤铁矿化过程与U，Th，Pb，REEs，Cu，Mo和W的大量富集和固定化以及Ni，Cr，V的贫化有关。