地层含金银性评价的地球化学准则——以扬子地台北缘中段中上元古界为例

GEOCHEMICAL CRITERIA FOR APPRAISAL OF GOLD-SILVER BERING ABILITY IN STRATA——With particular reference to the Middle-Upper proterozoic Suberathem in the middle section of the northern margin of Yangtze Platform

金银丰度的高低不是控制金银矿化的决定性因素。有利于金矿化的因素包括:较高的金银丰度;全银的几何平均值与算术平均值比较;金分布及银分布均为多峰偏态,对数分布为正态-正偏;易释放金比例高;地层中金银形成的元素组合同区域金银矿床的矿化元素组合接近。

On the basis of systematic studies on abundance, ratio of geometric average alu(?) to arithm(?)erage volue (X_(?)/X_(?)), distributive type, existing form and element combination of gold and silver in the Middl(?) Upper Proterozoic Suberathem in the middle section of the northern margin of Yangtze Platform, and through theoretical (?)nal(?)sis geoel(?)emical criteria for appraisal of gold and silver bearing ability in strata have been given in the paper: the ab(?)dance of (?)ol(?)and silver in strata is (?)ot a critical factor that causes the mineralization of gold and silver. The factors which f(?)our mineralization of gold a(?) silver are (?)) higher abundance of gold and silver; (2)lower ratio of geometric average value (X_(?) to arithm(?) a(?)rage v(?)lue(?), 3)poly peak(?) (?)istribution of gold and silver, logarithm normal or logarithm normal-skew distribution, ((?))higher ratio of acces(?)ole goldand silver; (5)a special gold-and sil(?) forming element combination, which is similar to mineralized element (?)om(?)ation of (?)ld-(?)ver depo(?)s in the area.