摘要
通过对麻棚岩体花岗岩类岩石主要的副矿物组合(磁铁矿、榍石、磷灰石、锆石等)和相应的含量以及矿物的形态、成分,特别是花岗岩中330粒和石英闪长岩中316粒锆石群形态学的研究,结合岩相学特征,探讨了花岗岩的成因、岩浆演化及其与金矿化的关系。确定麻棚岩体为岩浆成因,岩浆物质组成以壳源为主,有幔源物质混入,为Ⅰ型花岗岩;副矿物在相对氧化环境下结晶,锆石在900℃~600℃范围内结晶。锆石结晶温度跨度大以及斑晶具有黑云母等含水矿物,表明侵位前岩浆富含水分;锆石结晶温度的峰值变化以及岩石的斑状结构表明,岩浆在侵位时曾经发生过不同程度的气—液分离。岩浆结晶过程中的相对氧化环境和岩浆的气—液分离对金矿的成矿作用具有重要意义。
By combination of analysis of the association of accessory minerals of granitoid rocks of Mapeng rock mass including magnetite,titanite,apatite,zircon and other sulfides together with their morphology and position as well as the typology study of 330 grains of zircon in granite and 316 grains of zircon in tonalite,and the petrography,this paper discusses the granite origin and magmatic evolution,and their relationship with gold mineralization.It is shown that Mapeng rock mass is magmatic origin and belongs to I type granite which comes from lower crust with mantel material mixture.The accessory minerals are crystallized under a relatively oxidized environment,and the zircon crystallization temperature is from 900℃ to 600℃.The large span of zircon crystallization temperature and the presence of biotite and other water-bearing minerals in the phenocrystals indicate that the magma is rich in water before its emplacement.The peak variation of zircon crystallization temperature and the porphyritic structure of the rock reveal that different degrees of liquid-gas fractionation occurred in magma during its emplacement.There is a great significance of the relatively oxidized environment of magma during crystallization and the liquid-gas fractionation of magma for the gold mineralization.
作者
刘小滨
王殿良
董玉翠
杨建岭
赵雷
LIU Xiaobin;WANG Dianliang;DONG Yucui;YANG Jianling;ZHAO Lei(Geological Team No.4 of North China Geological Exploration Bureau,Qinhuangdao 066013,Hebei,China)
出处
《矿产与地质》
2023年第2期301-308,共8页
Mineral Resources and Geology
基金
全国危机矿山接替资源找矿项目(编号:﹝2006﹞077号)资助。
关键词
副矿物
锆石群形态学
花岗岩成因
岩浆演化
金矿
太行山
accessory mineral
zircon topology
granite origin
magmatic evolution
gold deposit
Taihang Mountain
