广西六万山花岗岩岩石地球化学特征及其成因探讨

Lithogeochemical characteristics and genesis of granite bodies in Liuwanshan of Guangxi

六万山花岗岩体形成于早三叠世,存在多个岩浆活动序次,其岩性主要为含堇青石的二长花岗岩。该类花岗岩富含过铝质矿物,高A/CNK,SiO_2、K_2O、TiO_2、Al_2O_3、MgO、FeO含量较高,Fe2O3、Na2O、P2O5含量较低。基于各类化学图解,并结合区域地质背景,表明该岩体是在同碰撞造山环境下形成的,地幔为该岩体形成提供了热源,还可能为其提供了一部分物源。

Liuwanshan granite bodies are formed in early Triassic epoch and occur in several magmatic activity series. In terms of lithology, the granite is a kind of cordierite granite which contains iolite. This kind of granite containsrich peraluminous minerals, and is enriched with SiO2, K2 O, TiO2, Al2O3, MgO, FeO and A/CNK, and is depleted in Fe2O3, Na2O and P2O2. Based on various geochemical plots and the regional geological settings, the results indicated that the earth mantle provided the thermal source and possibly some material sources for the formation of the rock bodies which occurred in a syn-collision orogenic environment.