河北红石砬铂矿床铂、钯地球化学异常特征

红石砬铂矿地球化学异常组分简单，仅发育Ｐｔ和Ｐｄ的强异常，部分伴生Ａｕ异常，不伴生Ｃｒ、Ｃｏ、Ｃｕ、Ｎｉ、Ｖ、Ａｓ、Ｓｂ、Ａｇ、Ｐｂ等元素异常。岩石、土壤、水系沉积物中Ｐｔ、Ｐｄ的分布和异常模式与铂族矿化特征、矿体剥蚀程度及其表生地球化学行为等有关。矿体出露地表时，Ｐｔ、Ｐｄ呈强异常分布，异常的ｗ（Ｐｔ）／ｗ（Ｐｄ）比值与矿石中ｗ（Ｐｔ）／ｗ（Ｐｄ）比率基本一致；隐伏矿体上方，Ｐｄ有明显的浓集，ｗ（Ｐｔ）／ｗ（Ｐｄ）比值小于地表矿体。表生环境中，Ｐｔ、Ｐｄ可以呈矿物碎屑、可溶态等多种形式迁移，在疏松沉积物中形成异常。因此，以Ｐｔ、Ｐｄ作为直接指示元素，进行地球化学勘查，可以发现这种类型的铂族矿床。

GEOCHEMICAL ANOMALY PATTERN OF PLATINUM AND PALLADIUM AT THE HONGSHILA PLATINUM GROUP ELEMENTS(PGE) DEPOSIT,HEBEI PROVINCE

In the Hongshila hydrothermal platinum mineralization area, significant geochemical anomaly with simple composition is characterised by close association of Pt and Pd accompanying with Au anomaly,but there is no anomalies of Cr,Co,Ni,Cu,V,As,Sb,Ag,Pb,etc.The distribution and anomalous patterns of platinum and palladium in the rock,soil and stream sediment at the mineralization area are related both to PGE mineralization type,the denudation degree of the ore body and to the PGE hypergene mobility. The strong anomalies with close association of Pt and Pd could be delineated at the surface exposure of economically important PGE deposit with the feature of that the Pt/Pd ratio of the anomaly approximate to the Pt/Pd ratio of the ore. The palladium enhanced concentrations are related to hidden PGE body. Therefor,the anomalous Pt/Pd ratio above the buried deposit is smaller than that of the outcroped body on the surface. In the surficial environment platinum and palladium can be displaced in the forms of mineral debris,solvent etc. The platiniferous deposit can form PGE anomalies in the sediments. Consequently,the hidden PGE deposit could be discovered by means of geochemical exploration with Pt and Pd as direct pathfinder elements.