Paleomagnetic study on Kuche depress of tarim block in early cretaceous and its inclination shallowing

The paleomagnetic results of Baxigai formation of early Cretaceous in Kuche depression,Tarim block are reported. Two magnetic components were clearly isolated by means of principal component analysis method and Linefind method. Overprint component is a remagnetization of Himalayan, which is close to the present magnetic direction. Characteristic magnetic remanence shows obviously offset present magnetic direction. After tilted correction, ChRM shows well consistent and passed reversal test. Early Cretaceous magnetic mean direction was obtained by summarizing most of published paleomagnetic data in this area. Inclination shallowing is noticed in the early Cretaceous stratum,which could not be explained by tectonics only if we consider the periphery plates. Some factors,such as quality of paleomagnetic data,sedimentary process,as well as long period non-dipole field and so on are excluded. The compaction is believed to be the most important factor resulting in inclination shallowing. Much more work should be done to verify this hypothesis and this will provide evident for solving the problem in tectonics.