南岭燕山早期花岗岩成因类型的进一步探讨

Some Further Discussions on the Genetic Type of the Early Yanshanian (Jurassic) Granitoids in the Nanling area,SE China

在对近年来公开发表的南岭地区燕山早期(侏罗纪)花岗岩的地质年代学和地球化学资料的综合分析基础上,本文指出南岭地区出露最广泛的黑云母花岗岩至少属于两种成因类型,即Pitcher(1982,1997)定义的S型和加里东I型,同时有一些黑云母花岗岩属于I型和S型之间的过渡类型。对于南岭燕山早期二云母和含白云母淡色花岗岩而言,它们与黑云母花岗岩在成因上没有联系,不是其分离结晶的产物,是地壳部分熔融产物,不是"分异I型花岗岩"。

Based on a compilation and comprehensive analysis of recent published geochronological and geochemical data of the Early Yanshanian （Jurassic） granites in the Nanling area, SE China, it is pointed out that there exit at least two genetic types for the biotite granites, which are mostly exposed in the Nanling area, i. e. S-and （Caledonian） I-type in the sense of Pitcher （1982, 1997）; meanwhile, there some biotite granites belong to the transitional granite between I- and S-type. However, there is not petrogenetic relation between the two-mica and muscovite-bearing leucogranites and the biotite granites in the Nanling area. The two-mica and muscovite-bearing leucogranites are not the fractionated ends of biotite granites, but the products of crustal melting. Therefore, the two-mica and muscovite-bearing leucogranites are not the “fractionated I-type granites” as argued by Li Xianhua and co-workers （2007）.