一种寻找被黄土埋藏的金矿床的地球化学勘查方法──选择性价态金测量

A New Geochemical Exploration Method for Loess Buried Gold Deposit ──Selective Valence Gold Survey

本文叙述了埋藏金矿床上覆黄土盖层中各种价态金的次生地球化学分散的研究成果。不同价态金在黄土垂直剖面的地球化学分布呈双层结构模式。由矿体（矿化体）至覆盖层底部，金的总量和游离态自然金（Ａｕ°）含量在短距离内（一般仅１～２ｍ）以对数率迅速由１０－６数量级衰减至１０－９数量级；但是，进一步在黄土层中其含量基本在黄土背景值上下波动。因此，仅在浅覆盖地段（一般仅数米），在地表可发现这种形态金的弱异常。与此不同，水溶态Ａｕ３＋和有机态Ａｕ＋含量在数十米厚的黄土层中基本保持其较高的异常含量水平，地表土壤测量可发现其清晰的异常。典型金矿化区应用研究表明，采用选择性价态金测量方法，可以探测被数十米厚黄土埋藏的金矿床（矿体）。

his paper details investigations of the secondary dispersion of every valence gold inthe loess-covered layer. At the vertical profile of loess overlaying hidden gold deposit, the distribution of various valence gold is present with a two-layer structure pattern. From ore (mineralization) they to the bottem of the covered layer, the content of total and free (native) gold (Au0)rapidly reduces from 10-6 into 10-9 grade with logarithmic decay in short distance (1-2m), butfurther their cantent in the covered layer mainly approaches to the background value of the loess.For this reason, weaker anomaly of this form gold only would be detected whereve there is severalmetres the thickness of loess layer. Oppsite from free gold, higher anomalous content of wetersoluble An3+ and organic An+ appears at the whole loess layer, which thickness may achieve toseveral decades metres, and so also their definitive anomalies ought to be discovered using surfacesoil survey. According to application inspection in the example gold metallogenic area covered byloess, it can be salt with certainty that gold hidden deposits (ore bodies), which was buried byseveral decades metres loess, would be explored by means of selective valence gold servey.