云南个旧Sn-Cu多金属矿田风流山矿段原生晕分带与深部成矿预测

Primary Halo Zoning and Deep Metallogenic Prediction in the Fengliushan Section of the Gejiu Sn-Cu Polymetallic Ore Field,Yunnan Province

云南个旧风流山矿段位于老卡岩体西侧,老厂矿田的南部,风流山Sn-Cu多金属矿段属于蚀变花岗岩型矿化,矿化发生于花岗岩内蚀变带,矿体受断裂和裂隙控制。运用格里戈良分带指数法对风流山34矿段第5勘探线剖面样品进行蚀变矿化分析和原生晕研究,探究其深部矿体赋存状况。(1)矿体原生晕分带清晰,原生晕展布形态与矿体空间分布相似。(2)由各断面的分带指数,得到矿体原生晕轴向分带序列为(由前缘至尾部):Mo-Sn-Bi-Ag-As-Cu-W-Co-F-Pb-Zn-Sb-B-U-Ta。(3)以风流山34矿段第5勘探线剖面分带指数为基础,选取(Mo×Bi×Zn)D/(U×B×Sb)D和(Mo+Bi+Zn)D/(U+B+Sb)D作为构建深部矿体定量评价模型的指标。根据比值的曲线变化规律,推测该矿段深部可能存在盲矿体。

The Gejiu Fengliushan ore section is located in the south of Laochang ore field and west of Laoka rock mass.This Sn-Cu polymetallic ore section belongs to an altered granite type deposit,where mineralization occurred in an alteration zone of granite and ore-bodies are controlled by faults and fissures.Using the Grigorian zoning index method,this work analyzes alteration mineralization and primary haloes based on tests of rock samples from the No.5 exploration line of Fengliushan 34 ore section.Results show that(1)the halos of orebodies exhibit a clear zonation.The distribution pattern of the primary halos is similar to the spatial distribution of the ore-bodies.(2)From the zoning indexes of every cross section,by calculating the variability index and gradient difference of the zoning indexes,the axial zonation sequence of orebody haloes is(from high to low):Mo-Sn-Bi-Ag-As-Cu-W-Co-F-Pb-Zn-Sb-B-U-Ta.(3)Based on the zoning indexes of the No.5 exploratory line of Fengliushan 34 ore section,this study selects(Mo×Bi×Zn)D/(U×B×Sb)D and(Mo+Bi+Zn)D/(U+B+Sb)D as indicators for constructing a model of deep ore-body quantitative evaluation.According to the curve variation of the ratio,it is speculated that blind ore-bodies likely exist at depth.