论文部分内容阅读
采自于北卡罗来纳州Rector Branch逆冲断层下盘塑性变形平行层理石英脉中的流体包裹体样品,经研究表明冷冻温度和均一温度的变化与距断层的远近,存在着一种函数关系。本文还对断层带(?)棱岩的流体包裹体及显微构造作了研究,石英脉具晶内塑性变形特征(发育多边形亚颗粒),其中的流体包裹体沿亚颗粒边界分布,相对于未变形样品,它具较高的均一温度(Th)和较宽的变化范围(120-320℃)。Th最大值接近于变形温度(300±20℃),明显的反映是流体包裹体沿亚颗粒边界消失。而Th最小值(120～160℃)则记录了近于300℃时的静岩环境(2.6kb)。最大冷冻温度(Tm)随着与断层距离的减小,从-20℃增至-4℃,这种变化与流体中的盐度从23wt%降至3wt%(NaCl当量)的变化相对应,而流体盐度的变化源于断层带扩容阶段地表水对断层深处(近于10km)的渗滤,断层带样品石英颗粒中的流体包裹体,沿愈合的显微裂隙分布,具较高的盐度(17-26wt%,NaCl当量),表明断层带中存在水合作用和流体—岩石之间的反应强烈。Rector Branch逆冲断层流体压力与盐度的变化与断层扩容—水力破裂模式一致,显然证实了断层带岩石体积大量损失的原因是,作为通道的断层带有不饱和地表水的加入。
Fluid inclusions from quartz fractures parallel to the plastically deformed lower disc of the Rector Branch, North Carolina, show that there is a functional relationship between changes in freezing temperature and homogenization temperature and distance from the fault. The fluid inclusions and microstructures of the ridges of fault zone (?) Have also been studied. The quartz veins have intragranular plastic deformation features (developing polygonal subparticles). The fluid inclusions are distributed along the sub-particle boundaries, The undeformed sample has a higher uniform temperature (Th) and a wider range of variation (120-320 ° C). The maximum value of Th is close to the deformation temperature (300 ± 20 ° C), a clear reflection of fluid inclusions disappearing along the sub-particle boundaries. While the minimum value of Th (120 ~ 160 ℃) recorded the rock environment (2.6 kb) near 300 ℃. The maximum freezing temperature (Tm) increases from -20 ° C to -4 ° C as the distance from the fault decreases. This change corresponds to the change of the salinity in the fluid from 23wt% to 3wt% (NaCl equivalent) The change of fluid salinity originates from the infiltration of surface water at the depth of the fault (nearly 10 km) by the surface water during the expansion phase of the fault zone. The fluid inclusions in the quartz grain of the fault zone samples distribute along the healing microcracks with higher Salinity (17-26 wt% NaCl equivalent) indicates hydration in the fault zone and strong fluid-rock reaction. Rector Branch The variation of fluid pressure and salinity in the thrust fault is consistent with the fault expansion-hydraulic fracture mode. It is clear that the large volume loss of the rock mass in the fault zone is due to the addition of unsaturated surface water as a fault in the channel.