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西藏柯月Pb-Zn-Sb-Ag多金属矿床位于雅鲁藏布江缝合带(IYS)与藏南拆离系(STDS)之间的北喜马拉雅成矿带。该矿床经详查验证,4 300 m以浅的矿体赋存于日当组钙质板岩夹薄层泥晶灰岩中,严格受北东向断裂控制,但深部延伸不明。本文通过该矿床I号矿体原生晕地球化学特征分析,对此问题进行初步探讨。研究表明,前缘晕元素为Hg、As、Tl,近矿晕元素为Pb、Zn、Sb、Ag、Au、Cd、Cu、Mn,尾晕元素为Sn、In、Bi;采用改良的格里戈良分带指数法计算分带序列为In-Mn-As-Cu-Zn-Cd-Bi-Pb-Sn-Hg-TlAg-Au-Sb,重心法计算分带序列为In-Mn-As-Cu-Cd-Zn-Hg-Bi-Sn-Pb-Ag-Sb-Tl-Au;同时,讨论原生晕地球化学参数变化规律,并以各元素的几何平均值累乘比建立矿体的剥蚀参数模型及矿体原生晕叠加理想模型。综合以上分析,推测矿床有多次成矿作用叠加,上部存在剥蚀至尾部的矿体,而深部可能有矿体延伸。
The Cu-Yue Pb-Zn-Sb-Ag polymetallic deposit in Tibet is located in the Northern Himalayan metallogenic belt between the Brahmaputra suture zone (IYS) and the South Tibet Detachment System (STDS). The deposit was verified by detailed investigation. The shallow ore body of 4 300 m occurred in the calcareous slate clayey limestone of the Rihodan Formation and was strictly controlled by the NE-trending faults, but the deep extension was unknown. Based on the analysis of primary geochemistry characteristics of I-type orebodies in this deposit, this issue is discussed. The results show that the front halo elements are Hg, As and Tl, the near-mineral halogens are Pb, Zn, Sb, Ag, Au, Cd, Cu and Mn and the tail halo elements are Sn, In and Bi. The Glehnian zoning index method was used to calculate the banding sequence as In-Mn-As-Cu-Zn-Cd-Bi-Pb-Sn-Hg-TlAg- At the same time, we discuss the variation rule of geochemical parameters of primary halo, and take the geometrical mean of each element to multiply and set up the erosion parameter of ore body Ideal model of superposition of model and ore body. Based on the above analysis, it is speculated that there are many mineralization superimposed deposits, the upper part of the existence of the ore body denuded to the tail, and deep may have ore body extension.