Paleomagnetic study of Cretaceous rocks from Pu'er, western Yunnan, China: Evidence of internal deformation of the Indochina block

摘要: Abstract Cretaceous red sandstones and siltstones were collected at 31 sties for paleomagnetic investigation from the Jingxing Nanxin Formation around Pu'er (23.0°N, 101.0°E), western part of Yunnan province, China, in order to examine quantitative amount tectonic deformation Simao Terrane due collision India with Asia. After stepwise thermal demagnetization, high-temperature component magnetization unblocking temperature 680 °C is isolated. Positive field tests show that 25 sites primary formations. A tilt-corrected mean direction D  = 59.9°, I  = 45.2° α 95  = 5.1°, corresponding a paleopole 35.8°N, 173.1°E  = 5.6°. Comparison pole whole China block indicates clockwise rotation area evaluated be 46 ± 9° respect block, which consistent large Mengla Jinggu areas (47° 66°) central Terrane. Clockwise larger by more than 20° compared Yunlong Yongping northern Terrane, suggesting experienced internal deformation. The southward displacement expected inclination data 7.5 ± 6.6° Chuan Dian fragment, similar estimate other Indochina block. While displaced 800 km together 30° as whole, further occurred part.