断层带中超压流体及其在地震和成矿中的作用

地震断层带中的局部存在对其力学和化学过程有着重要影响的超压流体，对这种超压流本的证据。超压机制及其在地震活动和成矿中的作用等进行了探讨。流体超压是在断层带中渗透性的构造发生强烈时空变化的前提下产生的，其主要原因是构造加压及深源高压流体的注入，当流体压力升至一临界值时，断层发生灾难性破裂，即地震，增加断层的渗透性，超压流体快速向低压带（室或域）流动，同时因减压流体所携载水溶物各（包括成矿物质）大量沉淀析出，降低断层带的渗透性，地震泵吸和流体超压机制的交替作用使得这一过程得以周期性地进行。

OVERPRESSURED FLUIDS IN FAULT ZONES AND THEIR ROLES IN EARTHQUAKE AND HYDROTHERMAL METALLOGENY

The influences of overpressured fluids on mechanical and chemical processes in faults are very important. Based on the summary of the former research accomplishments, discussion is given in this paper on evidences and mechanism for overpressure of fluids in faults and their relation to earthquake and hydrothermal metallogeny. The following conclusions are induced from the present related information and theory knowledge. The overpressured fluids located in faults are formed by tectonic compaction of country rock sourced fluids and injection of high pressured fluids from depth, under the precondition that the permeability structures are varied greatly in time and space. When the fluid pressures rise to a threshold, the catastrophic ruptures are broken out, that is earthquake, creating high permeability in the fault zone. Simultaneously, the overpressured fluids quickly flow to low pressured places, and a lot of aqueous soluble species, including metallogenic materials, are precipitated from the flowing fluids, resulting from dramatically dropping of fluid pressures and resulting in decreasing of permeability of the fault zone. These processes can be circulated by alternatively running of the seismic pumping and the fluid overpressure mechanism.