摘要
A paleomagnetic study was carried out on Early-Middle Jurassic sediments in the Zhenba area, the western South-dabashan orogenic belt. Stepwise thermal demagnetization isolated the characteristic high temperature component (HTC) (D=37.1°,I=46.1°, α95=10.1°), which passed the fold test. By comparing the corresponding pole of HTC (57.6°N, 196.6°E, A95=9.9°) with coeval reference poles for the Sichuan basin, we detected a 26.5°±9.0° clockwise rotation of the study area relative to the stable Sichuan basin. We interpret that this rotation was caused by obstruction of the Hannan block during thrusting of the Dabashan, and occurred around Early Cretaceous.
A paleomagnetic study was carried out on Early-Middle Jurassic sediments in the Zhenba area, the western South-dabashan oro- genic belt. Stepwise thermal demagnetization isolated the characteristic high temperature component （HTC） （D=37.1°,I=46.1°, α95=10.1°）, which passed the fold test. By comparing the corresponding pole of HTC （57.6°N, 196.6°E, A95=9.9°） with coeval reference poles for the Sichuan basin, we detected a 26.50°±9.0° clockwise rotation of the study area relative to the stable Sichuan basin. We interpret that this rotation was caused by obstruction of the Hannan block during thrusting of the Dabashan, and occurred around Early Cretaceous.
基金
supported by the China Postdoctoral Science Foundation (Grant No. 20080441182)
Momentous Subject (Structure and Oil-gas Foreground of South China)from China Petrochemical Corporation and the Postdoctoral Fellowship from Northwest University in China
