The 320 Ma Ghareh Bagh mica mine is the only active mica mine in northwest Iran, and hosts Mg-bearing biotite (phlogopite) with apatite, epidote, and calcite. Chemical investigation of apatite infers the high abundances of the rare earth elements (REEs up to 5619 ppm), higher ratios of the LREE/HREE ((La/Yb)_N = 28.5–36.7)) and high content of Y (236–497 ppm). REE pattern in the apatite and host A-type granite is almost the same. Ghareh Bagh apatite formed from the early magmatic-hydrothermal exsolved fluids at the high temperature from the Ghushchi alkali feldspar granite. The apatite crystals came up as suspension grains and precipitated in the brecciated zone. The early magmatic-hydrothermal fluids settle phlogopite, epidote, chlorite, K-feldspar and albite down in the brecciation zone. Due to the precipitation of these minerals, the late-stage fluids with low contents of Na⁺, Ca²⁺ and REE affected the early stage of alteration minerals. The high ratios of ⁸⁷Sr/⁸⁶Sr (0.70917 to 0.70950) are more consistent with crustal sources for the apatite large crystals. The same ages (320 Ma) for both brecciated mica veins and host alkali feldspar granites infer the apatite and paragenesis minerals were related to host granite A-type granite in the Ghareh Bagh area.

中文翻译：

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伊朗西北部Ghareh Bagh云母矿中大型磷灰石晶体的稀土元素和Sr同位素比：成因和成矿追踪

320 Ma Ghareh Bagh云母矿是伊朗西北部唯一活跃的云母矿，拥有含镁的黑云母（金云母），磷灰石，埃迪奥铁矿和方解石。磷灰石的化学研究推断出稀土元素的丰度很高（REEs高达5619 ppm），LREE / HREE（（La / Yb）_N= 28.5–36.7））和高含量的Y（236–497 ppm）。磷灰石与主体A型花岗岩中的REE模式几乎相同。Ghareh Bagh磷灰石是由Ghushchi碱性长石花岗岩在高温下由早期岩浆-水热溶解流体形成的。磷灰石晶体以悬浮颗粒的形式出现并沉淀在角砾化区中。早期的岩浆热液将金云母，附子，绿泥石，钾长石和钠长石沉积在速成区。由于这些矿物的沉淀，Na ⁺，Ca ²⁺和REE含量低的后期流体影响了蚀变矿物的早期。高比率⁸⁷ Sr / ⁸⁶Sr（0.70917至0.70950）与磷灰石大晶体的地壳来源更为一致。角砾岩云母脉和主体碱长石花岗岩的相同年龄（320 Ma）推断出磷灰石和共生矿物与加勒巴格地区的主体花岗岩A型花岗岩有关。