黔北黑色岩系的铂族元素地球化学特征及成因探讨

采用中子活化分析方法,系统测定了黔北黑色岩系的铂族元素含量。结果表明:金属富集层是铂族元素富集的首选层位。根据铂族元素丰度、元素相关性、特征参数值和元素配分模式,认为铂族元素并非来源于地外物质,而是海底含矿热卤水沿深大断裂而来。铂族元素的异常富集是海底热卤水与正常海水共同作用的结果。

ORIGIN AND GEOCHEMISTRY OF PLATINUM GROUP ELEMENTS OF LOWER CAMBRIAN BLACK SHALE SERIES IN NORTHERN GUIZHOU

There are some different opinions on the sources of platinum group elements, and correspondingly, there exist several models for their origin. The contents of platinum group elements(PGE)of the Lower Cambrian black shale series in northern Guizhou were determined using neutron activation analysis. The results showed that the contents of PGE reached its peak value in metal rich shales of the black shale series. The PGE abundance, elements' interrelation, related parameters and PGE patterns indicated that PGE might source from hot bittern seawater sediments from magma along the deep fractures, and high richments of PGE might result from mixing of hot bittern seawater sediments and normal seawater sediments, instead of the platinum elements coming from exo terrestrial materials.