摘要
本文列举的国内外大量、较精确的前寒武系变质岩中金丰度值及佳木斯中间地块624个变质岩金的分析数据表明,前寒武系变质岩中的金丰度值绝大多数在1.0-2.0ppb之间,明显低干金克拉克值。本文指出前寒武系变质岩中的金丰度值与金矿床之间不存在必然联系。研究前寒武系变质岩的含金性,应在于研究引起变质岩金异常值变化的各种地质因素,也就是使金活化、迁移及富集的种种机制。
A vast amount of relatively accurate gold abundance values in Precambrian metamorphic rocks at home and abroad and gold analytic deta of 624 samples from gold-bearing metamorphic rocks in the Jiamusi median massif listed in this paper indicate that the gold abundance values in Precambrian metamorphic rocks are mostly ln the range of 1.0-2.0 ppb,which are obviously lower than the Clarke value.It is proposed in this paper that the gold abundance values in Precambrian metamorphic rocks are of no special significance for locating gold deposits and there is no necessary relation between them.The author has observed and studied each rock sample which shows gold anomaly,and found that most of them have undergone alteration,mineralization or fraturing.She suggests that the spatial close relation of gold deposits with the Precambrian system is not dependent on the gold abundance value in metamorphic rocks,but on the mechanisms for remobilization,transport and eurichment of gold in metamorphic rocks.The polyphase tectonism,superimposed metamorphisim,complex magmatic(hydrothermal)activity and migmatization are very important geological factors for gold remobilization,transport and enrichment.The precambrian that has the longest evolution history possesses the geological factors mentioned above.
作者
刘静兰
Liu Jinglan(Institute of Geology,Heilongjiang Bureau of Geology and Mineral Resources,Harbin)
出处
《地质论评》
1988年第4期311-321,共11页
Geological Review
