青海玛日当沟钨矿床原生晕轴向分带特征及深部矿体预测模型

Axial zoning characteristics of primary halo and prediction model for deep-seated orebody of Maridanggou tungsten,Qinghai

玛日当沟钨矿床位于布喀达坂—青海南山成矿省同德—泽库印支期汞、砷、铜、铅、锌、金(锑、钨、铋、锡)成矿带内,是近年来发现的、受北北西向断裂构造控制的大型钨矿床。通过对该矿床地质特征、成晕元素共生组合的研究,基于格里戈良提出的分带指数计算方法获得了矿体原生晕轴向分带序列为Cu→Sb→Mo→Au→Pb→Zn→Ag→W→Bi,总体上与Beus and Grigorian总结的多金属矿床标准轴向分带序列基本一致。另外,基于分带指数建立了深部矿体预测模型,其预测评价指标(Cu×Sb×Mo)_D/(Ag×W×Bi)_D的自然对数与深度之间具有较好的线性关系,且该指标随深度的增加而有规律地降低,可作为深部矿体预测的有效指标。

Maridanggou tungsten deposit,a large-scale tungsten deposit discovered recently and controlled by NNE-trending faults,is located in Tongde-Zeku Indosinian Hg-As-Cu-Pb-Zn-Au（ Sb,W,Bi,Sn） metallogenic belt of Bukadaban-Qinghai Nanshan metallogenic province.By studying the geological characteristics and the halo elements association of the deposit,the halo zoning sequence of Cu→Sb→Mo→Au→Pb→Zn→Ag→W→Bi is acquired based on the computing method of zoning indexes proposed by Grigorian,and is overall basically concordant with the standard axial zoning sequence of polymetallic deposits summarized by Beus and Grigorian.Moreover,prediction model for deep-seated orebody has been constructed based on zoning indexes,the napierian logarithm of the prediction evaluation index of（ Cu×Sb×Mo）D/（ Ag×W×Bi）D for the model has a good linear relationship with the depth,and the index is regularly decreasing with the increasing of depth,therefore,it could be used as an effective index for predicting deep-seated orebody.