大别山花岗岩流体包裹体面的初步研究  

Preliminary Study on Fluid Inclusion Planes for Dabie Mountain Granite

作　　者：倪培[1] 范建国[1] 周进[1] 丁俊英[1] 马东升[1] 华仁民[1] 凌洪飞[1] 蒋少涌[1] 

机构地区：[1]南京大学成矿作用国家重点实验室地球科学系,南京210093

出　　处：《高校地质学报》2003年第4期691-700,共10页Geological Journal of China Universities

基　　金：国家攀登计划预选项目(95-预-39);国家自然科学基金创新群体项目(40221301)

摘　　要：地质流体是在应力作用下迁移演化的,把它们割裂开来研究是不可取的。流体包裹体面就是把地质流体与应力联系起来的好途径。通过对花岗岩流体包裹体面的研究,可以揭示花岗岩在侵位冷却过程中经受的区域应力场变化及受应力控制的流体运移和演化特征。统计了位于大别山碰撞造山带中的主薄原、天柱山和司空山三个花岗岩岩体的流体包裹体面产状,并对其中的流体包裹体进行了显微测温。数据显示,主薄原和天柱山岩体的流体包裹体面特征相似,有NE和NWW两个优势方向,其中NWW向早于NE向,从NWW向到NE向均一温度、盐度降低,CO_2含量下降;司空山岩体的流体包裹体面与主薄原和天柱山岩体的明显不同,有SN和EW两个优势方向,EW向早于SN向。从早到晚流体的演化趋势为高温、高盐度、含CO_2和CH_4的流体演化为较低温度、低盐度、基本不含挥发组分的流体。司空山岩体与主薄原和天柱山岩体侵位于不同的区域应力场下,流体的组分也存在一定的差别。但流体总的演化趋势一致:从高温、高盐度、富挥发分的流体向低温、低盐度、贫挥发分的方向演化。The devolvement and migration of geo-fluids is controlled by regional stress. Fluid in- clusion planes (FIP) are a bridge to link the gm-fluid and the stress. It is a useful means to inves- tigate the migration of the gm-fluid under certain regional stress field. Fluid inclusion planes kept in the granites provide the best way for us to study the regional stress field change and the fluid evolution when the granites intrude into the country rocks and cml down at the crustal environ- ment. This paper statistically surveys FIPs attitudes for three granitic intrusives in Dabie Moun- tain, Anhui province (Zhubeyuan, Tianzhushan and Sikongshan granites). Microthermometric works were also done on the fluid inclusions in FIPs. It is revealed that the characteristics of FIPs in the Zhubeyuan and Tianzhushan grantes are similar, but obviously different from the Sikong- shan granite. The FIP in Zhubeyuan and Tianzhushan granites have preferred orientations of NE and NWW. The NWW striking FIP are cross-cut by the NE striking FIP. The homogenization temperature, salinity and CO_2 contents of the fluid inclusions in NWW striking FIP are higher than those of NE striking FIP, which indicate regional paleo-stress change from NWW to NE strike accompanying the intrusion and cooling of the above two granites, and fluids evolved from CO_2-H_2O-NaCl type to H_2O-NaCl type with declined temperatures and salinities. FIP in Sikong- shan granite have preferred orientations of SN and EW. The EW striking FIP are cross-cut by the SN striking FIP. While cooling, the Sikongshan granite experienced a regional stress field chang- ing from EW to SN and fluid types changing from CO_2-CH_4-H_2O-NaCl type to H_2O-NaCl type with the declined fluid temperatures and salinities.

关 键 词：流体包裹体面 花岗岩 大别山 

分 类 号：P599[天文地球—地球化学] P588.121[天文地球—地质学]