关键词: 浅表型断裂, 深层地腹型断裂, 滑脱型断裂, 基底隐伏型断裂, 浅表-基底贯通型断裂

Abstract: This paper presents the identification and delineation of buried faults in Chengdu and Deyang depression, based on seismogeologic and petroleum prospecting data accumulated in the past 20 years by Seismological Bureau and Petroleum Administration Bureau of Sichuan Province. A very important question about whether a potential or buried fault exists in Chengdu and Deyang depression basin is answered. Seismo-geological data show that a fault starting from Xinjin and terminating to the south of Pengzhen, Shuangliu County does exist in the region. Furthermore, the relationships between active faults and seismic activities, as well as the related characteristics of the faults are discussed. At the same time, a strict distinction between the shallow faults and deep buried faults is made, and then their distributions are delineated. Five new types of seismogenic faults are proposed. Based on the above mentioned recognition, the potential areas of strong earthquakes in Chengdu basin are determined. The results show that the Chengdu-Deyang area of hundred kilometers in length and 40km in width possesses stable seismo-geologic environment and good conditions for earthquake engineering. This conclusion is of great importance to the economic developments and constructions, and especially to the assessment of seismic risk of major engineering sites in Chengdu basin.

Key words: shallow fault, deep fault, decollement fault, buried basement fault, Chengdu basin, seismo-geological background