摘要
金铜钨锡成矿与花岗岩的关系是学术界关心的话题。按照流行的岩浆热液成矿理论,钨锡是高温热液矿床,金铜是中温热液矿床,铅锌是低温热液矿床,它们与花岗岩时空和成因有关,可以围绕岩体分布,近岩体处为钨锡,向外为金铜,远处为铅锌。在一个成矿带中,钨锡金铜铅锌可以共存,且有众多矿床实例为佐证。我们的研究表明,金铜与埃达克型和喜马拉雅型花岗岩有关,形成于加厚地壳;钨锡与南岭型花岗岩有关,形成于减薄的地壳。在一个地区同时不可能地壳又加厚又减薄,因此,埃达克型花岗岩与南岭型花岗岩不可能同时同地共存,所以,在一个地区不可能同时既有金铜又有钨锡成矿,大量矿床实例也证明金铜与钨锡是相悖的。至于在许多地方出现的金铜钨锡铅锌等在一起的现象,可能有两种解释:要么它们是不同时代成矿互相叠加在一起的;要么它们正好处于地壳厚度急剧变化的地方。为了查明金铜钨锡成矿究竟是相伴还是相悖的,至少需要掌握3个方面的资料:(1)不同矿床成矿的时代;(2)不同矿床与花岗岩的关系及花岗岩的地球化学特征和同位素年龄;(3)不同矿床的成因及矿床类型。
The relationship between Au-Cu-W-Sn mineralization and granitic rocks is a topic which are concerned in academic circles. The popular magmatic hydrothermal metallogenic theory assumed that W-Sn deposits are high temperature hydrothermal deposits; Au-Cu deposits are mesothermal deposits; Pb-Zn deposits are low temperature hydrothermal deposits. The deposits are related with granites in time, space and genesis and they are distributed around the rock body. W-Sn deposits are distributed nearly the rock body, and outward for Au-Cu deposits, Pb-Zn deposits to the distance. In a metallogenic belt, there are numerous examples that W-Sn- Au-Cu- Pb-Zn deposits are located in the same place. But our research shows that Au-Cu deposits are related with adakitic-type and Himalayan-type granitic rocks which formed from thicked crust, whereas W-Sn deposits are related with Nanling-type granitic rocks which formed from thinned crust. Therefore, adakitic-type granitic rocks and Nanling-type granitic rocks cannot be located in the same place at the same time. So do Au-Cu-W-Sn deposits. There are two kinds of interpretation about W-Sn-Au-Cu-Pb-Zn deposits are located in the same place： one is these deposits have different metallogenic epochs, another one is these deposits are located in the places with crust thickness rapid changes. In order to find the relationship between Au-Cu and W-Sn mineralization, we need three aspects data at least： （1）metallogenic epochs of different deposits; （2）the relationship between different deposits and granitic rocks and geochemical characters and isotope age of the granitic rocks; （3）the genesis and types of different deposits.
出处
《甘肃地质》
2013年第2期1-13,共13页
Gansu Geology
基金
国家自然科学基金重大研究计划(91014001)项目资助的研究
关键词
金铜
钨锡
花岗岩
热液
成矿理论
Au-Cu deposits
W-Sn deposits
Granite
Hydrothermal
Metallogenic theory
