广西热水沉积矿床中电气石岩地质地球化学特征

Geological-geochemical Characteristics of Tourmalite of Hydrothermal Sediment Deposits in Guangxi Province

本文从岩石学和地球化学分析角度,研究广西热水沉积矿床中电英岩的地质地球化学特征。电英岩在Al2O3-TiO2及Al2O3-(K2O+Na2O)图解上的坐标落在热水沉积区内,为热水沉积形成。电英岩的稀土分配模式具有轻稀土富集,弱的负Ce异常和负Eu异常,为典型的热水沉积物的分布模式。电英岩的δ18O值很低,较一般的热水沉积硅质岩低,可能是热水沉积电气石岩的固有特征,表明应属热水沉积成因。

From the view of petrology and geochemistry,this work makes analysis to geological and geochemical characteristics of tourmalite of hydrothermal sediment deposits in Guangxi.The plot of Al/（Al＋Fe＋Mn）and Al-Fe-Mn triangle diagram shows that the tourmalite lies in the area of hydrothermal sediments,implying its formation mechanism.The rare earth elements distribution patterns of the tourmalite has weak negative Ce and negative Eu anomalies,indicative of typical patterns of hydrothermal sediments.The δ^18O value of tourmalite is lower than other general hydrothermal sediment silicalites,and is probably the inherent feature of this kind of tourmalite deposits that formed in thermal sediment setting.