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从矿物学角度看,法国的舍金滑石菱镁片岩(listvenite)与某些金矿脉是个分类似的。这种相似性表明超基性岩是这些脉中大部分金属(Fe,Mg,Ni,Co,Au)的主要来源。金首先赋存于早期形成的磁黄铁矿中(在Hermites脉中可达30ppm),并在这些磁黄铁矿分解转变为黄铁矿-白铁矿组合时从中分离出来。金从而也获得了其确定的矿物学形式:或呈自然金出现,这时磁黄铁矿的分解是发生在矿化晚期(如在开放型大脉中),或者“隐藏”在含铁硫化物如毒砂(可含1.6%金,在chatelet脉中)、黄铁矿和辉铁锑矿(可含300ppm金,在Marmeissat脉中)中,这时磁黄铁矿的分解是发生在矿化早期(如在无明显张裂的“剪切带”式矿床中)。在后一种情况下,我们应该考虑到在含铁硫化物中存在Fe、Au置换的可能性。
From a mineralogical point of view, the French listvenite is similar to some gold veins. This similarity shows that ultramafic rocks are the major source of most of the metals in these veins (Fe, Mg, Ni, Co, Au). Gold first occurs in early formed pyrrhotites (up to 30 ppm in the Hermites veins) and is separated from these pyrrhotite decompositions as pyrite-marcasite combinations. Gold also gained its defined mineralogical form, either in the form of natural gold, when the decomposition of pyrrhotite occurred in late mineralization (as in the open macro-veins) or “hidden” in the ferrous sulphide Such as arsenopyrite (which can contain 1.6% gold in the chatelet vein), pyrite, and cryptocristite (which can contain 300 ppm gold in the Marmeissat), when pyrrhotite is decomposed in the ore In the early stage (as in a “shear zone” type deposit with no apparent tension). In the latter case, we should consider the possibility of substitution of Fe and Au in iron-bearing sulfides.