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京希—伊尔曼德金矿床的热液蚀变在空间上有明显的分带性,中心蚀变带以强烈的硅化为主,典型的蚀变矿物组合为石英或玉髓和地开石,中间带为高级泥化带,以地开石-高岭石-石英或玉髓为特征;外带为以蒙脱石-高岭石-伊利石-其他粘土矿物等矿物组合为主的泥化带,蚀变强度和矿物组合的分带性是温度、压力和化学梯度的反映,是流体在不断的水或流体—岩石反应和成分交换的产物。该矿床成矿流体演化过程为:早期酸性(pH=2～3)含矿流体在沿断裂上升过程中,受围岩灰岩中的流体(pH为中性)缓冲,在其进入高渗透性的碎屑岩层时,流速和水—岩石或流体—岩石反应大大加快,并在与大气降水的混合作用下,pH值逐步升高(3～5),产生了流体的温度及成分梯度,在温度和压力迅速下降的条件下,金及蚀变矿物沉淀、结晶生长,形成了蚀变空间分带,中心带保存完好的多孔状石英和地开石等高级泥化矿物组合说明该矿床是高硫化热液体系作用下的产物。
The hydrothermal alteration of the Jingxi-Ilmende gold deposit has obvious zonation in space. The central alteration zone is strongly silicified. The typical alteration mineral assemblages are quartz or chalcedony and dickite , The middle zone is a high-grade muddy zone characterized by dickite-kaolinite-quartz or chalcedony; the outer zone is mud dominated by a combination of minerals such as montmorillonite-kaolinite-illite-other clay minerals Banding, alteration, and banding of mineral assemblages are a reflection of temperature, pressure, and chemical gradients and are the product of fluid-fluid-fluid-fluid-rock reaction and component exchange. The evolution process of ore-forming fluids in this deposit is that the early acidic (pH = 2 ~ 3) ore-bearing fluids are buffered by the fluid (pH-neutral) in the surrounding rock limestone along the rise of faults, , The flow rate and the water-rock or fluid-rock reaction greatly accelerate, and the pH gradually increases (3-5) due to the mixing with the precipitation, resulting in the temperature and composition gradient of the fluid Under the conditions of rapid decrease of temperature and pressure, the gold and alteration minerals precipitate and grow in crystal, resulting in the alteration space zonation, the combination of well-preserved porous porous quartz and dickite and other advanced clay minerals indicating that the deposit is high Sulfated hydrothermal system under the action of the product.