河南桐柏地区银洞坡金矿床地球化学特征

银洞坡金矿床地球化学特征研究表明，成矿元素含量变化与歪头山组的地层层序、岩石类型密切相关，不同层位、不同岩石类型之间，成矿元素明显不同。歪头山组中上部炭质绢云石英片岩Ａｕ、Ａｇ含量最高，成为金银矿体的直接赋矿围岩，变粒岩及云母石英片岩中成矿元素含量相对较高，它们与炭质绢云石英片岩共同构成矿源层。矿石的常量元素和稀土元素特征显示，矿石均为蚀变的构造岩，蚀变作用导致成矿元素显著带入，而对稀土元素的迁移影响不大。根据元素水平及垂向分带序列，认为成矿热液的运移以渗流作用为主，渗滤作用为辅。根据矿体不同标高的元素比值，建立了地球化学评价标志，为矿床深部及外围找矿提供了地球化学依据。

GEOCHEMICAL FEATURES OF THE YINDONGPO GOLD DEPOSIT IN TONGBAI REGION,HENAN PROVINCE

Research on the geochemical features of the Yindongpo gold deposit shows that the contents of ore forming elements relate closely with the stratigrahic sequence and rock types of the Waitoushan Formation. The distributions of ore forming elements change obviously in different stratigraphic horizons and rock types. In the middle and upper Waitoushan Formation, the carbonaceous sericite quartz schist, with the highest contents of Au and Ag, is the direct host rock, while the leptynite and the mica quartz schist contain rather higher ore forming elements. They constitute source beds together. The features of the invariable elements and the REEs of ores show that all kinds of the ores belong to altered tectonite. The alteration leads to notable increase of ore forming elements but has little influence on the migration of the REEs. According to the horizontal and vertical zoning succession of the elements, the authors consider that the migration of the hydrothermal ore forming solution relied mainly on seepage movement while making infiltration subsidiary. According to the element ratios of various elevations, the authors also establish geochemical evaluation indices and thus provide geochemical basis for guiding ore prospecting in the deep and periphery of the mining area.