铂族元素矿床地球化学勘查的战略和战术

Strategy and Tactics for Geochemical Exploration of Platinum Group Elements Deposits

最近10年,PGE地球化学勘查取得许多进展,在此对主要进展作一简短的评述。①通过对已知其它金属矿床的再认识和再评价,发现新类型PGE矿床;②通过对已知PGE矿床的地球化学勘查,发现新的找矿靶区;③在空白区通过PGE地球化学填图,发现规模巨大的PGE地球化学省或巨省,为寻找PGE矿床提供了直接的找矿信息。根据中国的具体情况提出了中国PGE地球化学勘查的战略目标是:采用迅速,掌握全局,逐步缩小靶区的找矿战略,力争用5～10a时间使PGE矿床找矿获得重大突破。部署工作应以西南Pt、Pd地球化学省、新-甘-青Pt、Pd地球化学省、雅鲁藏布江Pt、Pd地球化学省为重点地区。根据1:20万化探资料,建议以康滇地轴为首选地区,找寻的PGE矿床类型包括诺里尔斯克型和构造蚀变岩型PGE矿床（新类型）。PGE地球化学勘查的战术是样品测试时除测试Pt、Pd外,还要分析Au、Cu、Ag、Ni、As、Sb、Bi、Cd、Hg、F、S、Pb、Zn等元素。进行异常评价中如发现Pt、Pd、Cu、As、Cd元素和Pt、Pd、Cu、As、Cd、Pb、Zn元素组合异常时要引起特别重视,这往往是PGE矿化的特征标志。

This paper briefly reviews the progress made in the geochemical exploration of platinum group elements (PGE) ore deposits in the past 10 years. First,new types of PGE ore deposits were found during the reinvestigation and reevaluation of known ore deposits of other metals; second, new targets of PGE ore deposits were discovered by geochemical exploration in peripheral areas of known PGE ore deposits; and last, the geochemical provinces or megaprovinces of PGE were delineated by geochemical mapping of PGE in unknown areas. The strategic aim of geochemical exploration for PGE in China is to find new PGE ore deposits in the next 5 to 10 years, which can be attained by means of the exploration strategy of taking a comprehensive view of the general situation and realizing gradual reduction of the area of PGE target. The strategic targets for exploring PGE are the geochemical provinces of Pt and Pd in Yunnan-Guizhou-Sichuan-Guangxi area, Xinjiang-Gansu-Qinghai area and Tibet. In the light of the data of RGNR, the Xikang-Yunnan earth's axis is held to be the most important area for exploring PGE deposits. The PGE ore deposits should include Noril'sk Ni-Pt and PGE mineralization of altered basalt rock in the ductile shear belt. The exploration tactics of PGE should analyze not only Pt and Pd but also Au, Cu, Ag, Ni, As, Sb, Bi, Cd, Hg, F, S, Pb and Zn. The anomalous associations of Pt,Pd, Cu, As, Cd or/and Pt, Pd, Cu, As, Cd , Pb, Zn are diagnostic indicators of concealed or blind PGE ore deposits.