Abstract:

 Relics of faultage cliff in Carboniferous carbonate rocks are one of the distinct landforms resulted from neotectonic movement in the study area. Frictional traces and kinematic indicators on various fracture surfaces within the relics demonstrated that a nearly EW trending, left lateral strikeslip fault extending from Chuanzhusi in the west to Huanglong village in the east occurred since the MedioPleistocene. The recognized ChuanzhusiHuanglong strikeslip fault cut off an older SN trending Minjiang thrusting system, running eastwards, following and reworking the previous Xueshan Thrust Belt, and finally transforming itself into three alternating fault components: (1)growing into a group of NE trending shear bands at its northern side, (2)becoming interlayergliding at its front where the layering subparallel to the fault，and (3)transforming its movement sense to be an oblique down slip along a SN trending Huya thrust at its southern side. The geometry and kinematics of the ChuanzhusiHuanglong strikeslip fault and its regional tectonic relationships with the Minjiang and the Huya thrust system are in favor of a left lateral transform strikeslip fault system. The data derived from interpretation of satellite remote sensing images, the analysis of seismicity in 19702008 and the displacement vector field induced by GPS measurements that repeated four times since 1991 in the SongpanPingwu Area show that the ChuanzhusiHuanglong strikeslip fault system is an active transpressional shear belts developed following the eastern KunlunMinjiang transpressional shear fault system, and is one of the typical seismotectonic model in the northeastern corner of the QinghaiTibet Plateau, indicating the eastward escape of the Tibet Plateau materials.

Key words: ChuanzhusiHuanglong, faultage cliff, frictional traces, seismotectonic, transpressional shear belts