CAJ | 학술논문

Western Yunnan is located at the boundary of collision or underthrusting zone of Eurasian plate and is influencedby many times tectonic movements. With very complex geological environment and tectonic background, it is oneof the seismically active areas. In the paper, the teleseismic records were selected from 16 national, local and mo-bile stations, including 4 very-wide-band mobile stations of PASSCAL. And nearly 2 000 receiver functions wereextracted. Two measuring lines are 650 km and 450 km, respectively and across some major tectonic units inWestern Yunnan. It is indicated that Nujiang might be a seam characterized by underthrusting. The western andeastern boundaries of Sichuan-Yunnan rhombus block, i.e., Honghe and Xiaojiang faults, might be an erectionseam or collision belt. Panxi tectonic zone still has the characteristics of continental rift valley, that is, the surfaceis hollow and the upper mantle is upwarping. The tectonic situation in Western Yunnan is of certain regulation withthe interlacing distribution of orogenic zone and seam. The crustal thickness decreases gradually from the north tothe south and the S wave velocity is globally lower here.