节点文献
云南铂族元素找矿基础问题
BASIC PROBLEMS IN PROSPECTING FOR PLATINUM GROUP ELEMENT IN YUNNAN
【摘要】 云南省铂族元素矿床成矿地质条件较好 ,已有不少已知矿床、矿点、找矿信息及地球化学异常。找矿重点以基性超基性岩型为主 ,也应考虑其它类型 ,如热液型、黑色页岩型、煤岩型等。找矿重点地区除在峨眉山玄武岩分布区及其周边外 ,应注意康滇地轴中部及边缘中新生代断裂带通过的地区。峨眉山玄武岩分布区外围的卡林型金矿和浅成低温热液型矿床分布区亦值得重视 ,如滇东南地区。此外 ,寒武系黑色岩系及含磷层位的含铂性是一个具有挑战性的新课题 ,值得加强研究。云南铂族元素矿床的成矿时代 ,可能从元古代到新生代均有 ,对云南找铂来说非常有利 ,其它省区无法与之相比。新生代构造可能将深埋的矿体错动到浅部 ,找矿中需要特别注意 ,不妨“沿河找矿”。第四纪的风化壳中是否有铂族元素的富集也可探索。
【Abstract】 In Yunnan, with better conditions of PGE metallogenesis, there are a lot of known ore deposits, occurrences, prospecting information and geochemical anomalies. However, some problems must be put forward in the ore prospecting, Firstly, even most of the known PGE doposits hosted with in mafic-ultramafic rocks, it is also to discover new types of PGE deposit in black shales, such as the Cambrian P-bearing beds. Secondly, besides most known PGE deposits in Hercynian stage, there are PGE deposits formed in other periods, such as the PGE in Pt Dahongshan Fe-Cu deposit and the enriched PGE in the weathering crust of mafic-ultramafic rocks. Thirdly, even most known PGE deposits are in various geological settings, the Emei mantle plume with mafic and ultramafic intrusions is the first choice in prospecting for PGE. It is worth pointing out that the Mz and Cz tectonic movements could convey the P PGE deposits and their hostrocks into a new position near the surface, such as the Baimazhai Cu-Ni-PGE deposit, etc. It is important to discriminate basalt-induced and ore-induced geochemical anomalies in NE Yunnan, where the P Emei mantle plume exerted a key role in the formation of possible PGE deposits. It is also necessary to point out that suitable methods must be applied to evaluation economic ores, including natgural and manual heavy mineral methods, because of the strong heterogeneity of PGE distribution in ores and ore-hosting rocks.
【Key words】 Pt Group Element; Deposit Type; Metallogenic Episode; Prospecting Guides; Emei Mantle Plume; Yunnan Province;
- 【文献出处】 云南地质 ,Yunnan Geology , 编辑部邮箱 ,2003年03期
- 【分类号】P618.53
- 【被引频次】17
- 【下载频次】246