西藏玉龙成矿带各贡弄、恒星错、马牧普地球化学异常优选评价

各贡弄、马牧普、恒星错为玉龙成矿带上具有找矿潜力的地球化学异常区,综合考虑成矿地质条件和地球化学数据的异常区评价方法能降低资源勘查的风险和投入.本文采用确立评价指标并量化赋值,按指标的得分对异常区进行优选评价的方法,分析了各异常区的地质特征并类比玉龙成矿带的成矿地质背景确定地质评价指标(GP),并据此分析异常区以铜为主的多元素水系沉积物测量数据,将衬度、面金属量、元素组合、变异系数作为地球化学评价指标(GCP).对各指标按其对成矿有利程度赋值,根据评价指标赋值和权重对异常区进行打分,最后用现有工作程度的勘查成果对上述优选结果进行检验,优选结果与实际矿床规模一致,得分高的地区其资源潜力大,将定性的成矿地质条件量化,可提高异常区优选评价的可靠程度.

Optimal Selection Assessment on Geochemical Anomalies at Gegongnong,Hengxingcuo,Mamupu in the Yulong Metallogenic Zone,Tibet

Gegongnong,Mamupu and Hengxingcuo,the three geochemical anomalies in the Yulong metallogenic belt,have resource potential.Optimal selection method of combining the geological background with the geological characteristics can reduce exploration risk and investment.This paper gives a geochemical evaluation index and a quantitative indicator to assess the optimal selection of geochemical anomalies.The geological evaluation index(GP) is determined by analyzing the geological conditions and the similarities of the geological characteristics in the three areas of the Yulong metallogenic belt,and the geochemical evaluation index(GCP) is determined on the basis of the copper-based multi-elements stream sediment survey data in three zones.Values of the evaluation indexes are assigned according to indicators roles in the mineralization.The final scores of the three areas are determined by combining the score and the weight of GP and GCP.Finally,the optimization results,which show consistence with the scale of the deposit,are verified with the exploration results.It is suggested that the high value areas have huge resource potential and that the evaluation reliability can be improved by better quantification of the geological conditions.