壳幔物质相互作用在形成巨型内生矿床中的作用:同位素地球化学方法  

Using isotope geochemistry to discuss the role of crust-mantle interaction in the formation of endogenetic mega-deposits

作　　者：张立生 

出　　处：《世界核地质科学》2005年第3期147-152,共6页World Nuclear Geoscience

摘　　要：某些巨型矿床的同位素特征和研究20个矿床(其中10个是巨型矿床)所得到的新成果表明,它们都有壳幔相互作用的痕迹。业已查明,这种相互作用在许多场合下都发生在地幔中,详细讨论了巨型矿床成因的同位素地球化学理论。按照这个理论,这些矿床是一种特殊现象,无论成矿元素的多样性如何,它们都有地幔中的壳幔相互作用所产生的地幔交代这样一个共同的因素。可以把作为不相容元素巨量堆积的花岗岩看成是巨型矿床的类似物;按照统计的结果,它们有可能在大约2 Ga 前的某个发展阶段系统富集,在这个阶段,物质的再循环伴随有显著的、产生地幔中所缺少的挥发分的壳幔相互作用。Isotope characteristics of some mega-deposits from literature and new results on twenty deposits （ten of them are mega-deposits） show that there exists traces of crust-mantle interaction. It has been established that the interaction all took place in the mantle under many situations. The theory of isotope geochemistry on the genesis of mega-deposits has been discussed. According to the theory, these deposits are a kind of special phenomena, but they have a common factor, i.e. mantle metasomatism produced by the crust-mantle interaction in the mantle no matter what the ore-forming elements diversity may be. The granites with great accumulation of uncompatible elements can be considered as the analogues of mega-deposits. According to the statistical results, it is possible that they formed at a period before about 2Ga during which the recycling of the materials was accompanied with the obvious crust-mantle interaction and can produce the volatile components which are poor in the mantle.

关 键 词：壳幔作用 巨型矿床 同位素地球化学 

分 类 号：P597.3[天文地球—地球化学]