内蒙花敖包特Pb-Zn-Ag多金属矿床原生晕分带特征与深部矿体预测模型

花敖包特Pb-Zn-Ag多金属矿床构造上位于滨西太平洋成矿域内蒙古大兴安岭成矿带南段, 是一个近年来发现的与白垩纪早期构造岩浆活动有关的隐伏热液脉状矿床.研究表明: (1)矿体原生晕发育, 且分带明显.据其异常强度建立的元素横向分带顺序(从强到弱)为Cd→Pb→Zn→Ag→Sb→In→Hg→As→Cu→Sn→W→Mo→Bi, 排在序列前面的Cd、Pb、Zn、Sb、Ag等5种元素, 可作为远矿指示元素; 排在序列后端的As、Bi、Mo、W等4种元素, 可作为近矿指示元素.(2)根据Grigorian原生晕分带计算方法, 获得矿体原生晕轴向分带序列(自矿体头部至尾部)为Sb→Pb→Cd→Ag→Zn→Hg→Cu→In→As→Bi→Sn→Mo→W, 与Grigorian建立热液矿床标准分带基本一致.(3)构建深部矿体找矿模型, 其预测评价指标(Sb×Pb×Cd×Ag)_D/(As×Sn×Mo×W)_D在矿体头部为1.30、矿体中上部为0.35、矿体中下部为0.056、矿体尾部为0.005, 这表明该指标随深度的增加有规律地降低, 是预测深部矿体资源潜力的有效指标. 

Characteristics of Primary Halo Zonation and Prediction Pattern of Deep Orebody of the Huaaobaote Pb-Zn-Ag Polymetallic Deposit,Inner Mongolia

The Huaaobaote Pb-Zn-Ag polymetalic deposit, tectonically located at the south segment of the Dahinggan Mountains ore-forming belt of the circum-western Pacific metallogenetic domain, is a buried hydrothermal vein deposit associated with early Cretaceous tectono-magma activities discovered in recent years. The following conclusions are drawn by studying on primary halos of ore bodies. (1) The ore and halos forming-elements exhibit a clear zonation. Based on their anomalous intensity the transverse element zonation of the ore deposit are established as follows (from high to low): Cd→Pb→Zn→Ag→Sb→In→Hg→As→Cu→Sn→W→Mo→Bi. The five elements (Cd、Pb、Zn、Ag、Sb) ranked in the front of this zoning sequence can be regarded as long range indicators; and the four elements (Sn、W、Mo、Bi)in the rear of this zoning sequence regarded as short range indicators. (2) The axial zonation of this ore deposits is as follows: Sb→Pb→Cd→Ag→Zn→Hg→Cu→In→As→Bi→Sn→Mo→W, which is similar to the standard zonation of hydrothermal ore deposits determined by S.V. Grigorian. (3) Indexes such as (Sb×Pb×Cd×Ag)_D/(As×Sn×Mo×W)_D are constructed as a criterion for evaluating the ore potential in depth, which is equal or greater than 1.30 on the top portion of the ore bodies, 0.35-0.056 in the middle- upper portion, 0.056-0.005 in the middle-lower portion and equal or lesser than 0.005 at the end portion of the ore bodies, illustrating that the criterion values decrease regularly and abruptly with depth, and they can be used for predicting the ore potentials at a given depth.