花岗岩包体的形成机理——以湘东白莲寺地区花岗岩为例

FORMATION MECHANISM OF ENCLAVES IN GRANITE TAKE THE GRANITES IN BAILIANSI AREA OF EASTERN HUNAN AS EXZAMPLE

本文所讨论的包体,昔日统称析离体。笔者通过对白莲寺地区花岗岩中包体的研究,认为区内早期花岗闪长岩、石英闪长岩及黑云母二长花岗岩的形成以深熔作用为主、晚期二云母(白云母)二长花岗岩,花岗斑岩,石英斑岩,则应以分离结晶作用为主;花岗岩中之色体是火成的同源包体,它是由来自地幔的基性物质影响下形成,其机理本质上与海底玄武质熔岩形成岩忱的机理相同。

The enclaves discussed in this paper used to be called as schlieren. Through investigation of the enclaves in Bailiansi area, the author considers that the formation of the early phase granodiorite, quartz diorite and biotite monzogranite is dominated by anatexis, while the late phase two-mica monzogranite. granite-porphyry, quartz porphyry are formed chiefly tkrough fractional crystallization. The enclaves in granite are igneous autolith, which are formed under the influence of the Mantle-derived basic material. Their formation mechanism is essentially similar to that of rock pillow formed by sea-floor basaltic lava.