金矿源岩研究与判定

近二十年来,金矿源岩研究引起了国内外地质学家们的极大关注,这不仅仅是因为在理论上任何一个矿床的研究都不可能不涉及矿源问题,更重要的在于它在找矿中的重要意义越来越彼人们所认识.尤其是进入七十年代以来,伴随着全球性早前寒武纪地壳演化模式的建立,人们注意到占世界累积产量50％以上的金来自于太古宙绿岩带或包含绿岩带的地质单元之中这样一个地质事实,从而促使地质学家们开始提出了一些新的成因观点,并相应建立了由岩浆侵入体或变质作用提供热源,导致热流体对流循环,淋滤围岩中的金,在有利空间沉积成矿的金矿成因模式。这个模式的建立曾风靡全球,进而使金矿源岩研究,特别是太古宙古老地盾区的金矿源岩研究一跃而成为金矿找矿和予测方面的重要课题之一。在我国,有关金矿源岩问题已经开展了相当多的研究工作,积累了大量的资料并收到了一些成效,但是,不能不指出围绕着金矿源岩研究还存在一些问题,它们主要表现为:

STUDY AND DETERMINATION ON THE SOURCE ROCK OF GOLD ORE DEPOSIT

The study and determination on the gold source rock is an important part in genetic research for gold ore deposit.The original gold in rocks can be divided into two groups: the easy-released gold and the uneasyreleased one.The former joins the formation of gold ores, whereas the latter is what we get from the analysis of trace gold, which can oniy represent the quantity of the uneasy-released gold in the rocks after the easy-released gold had been lost.Thus the auther thinks that it is unreasonable to determine the gold source rocks only by the quantity of trace gold in the rocks. Since this study is a complex geological problem, it is necessary for us to investigate the existing state of gold in different rocks and miner rals after making sure of its geological setting.Many elements, both relative and unrelative elements to gold, can be helpful for the determination of the gold source rock.Pd, for example, is very useful to determine the original quantity of trace gold in ultramafic and mafic rocks.