Advances in Earth Science
• Articles •
LIU Liang-ming. OVERPRESSURED FLUIDS IN FAULT ZONES AND THEIR ROLES IN EARTHQUAKE AND HYDROTHERMAL METALLOGENY[J]. Advances in Earth Science, 2001, 16(2): 238-243.
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.