Longevity of fracture in crystalline rocks by using Rb-Sr dating method

本文着重研究了花岗质岩石中裂隙的形成过程和形成时代。结果表明，不同岩体具有相同的破裂和裂隙充填幕式，包括：脆性张裂，由于温度降低，通过韧性-脆性转变后的深大侵入（第I阶段）;相对快速的抬升，伴随着热液循环，产生未破碎的层状矿物充填物隆升暴露后的低温大气降水循环期（第三阶段）。碳酸盐矿物裂隙充填物及其碳同位素组成的共生<14C>关系<13>表明，在岩体快速隆升过程中存在明显的碳酸盐矿物沉淀幕。在每一幕中形成的碳酸盐矿物都含有来自不同来源的碳。这里确定的填充物的演变，使开发一个特定的模型的断裂和持久性的流体传导系统中的岩体的造山带。

In this research, formation process and the age of formation of fracture in granitic rocks has been focused. The result shows that different plutons have identical episodes of fracturing and fracture filling, consisting of : brittle tensile fracturing, due to decreasing temperature through the ductile-brittle transition after plutonic intrusion(Stage I); relatively rapid uplifting accompanied by hydrothermal water circulation which produced un-crushed layered mineral fillings(Stage II); and a period of low-temperature meteoric water circulation following exposure after uplift(Stage III). The parageneses of carbonate mineral fracture fillings and their carbon isotopic compositions(^<14C>,δ^<13> C) show that there were distinct episodes of carbonate mineral precipitation during the rapid uplifting of a pluton. The carbonate minerals that formed during each episode incorporated carbon from a distinct source. The evolution of fillings identified here enable development of a specific model of fracturing and persistence of fluid conducting systems in the plutons of the orogenic field.