This work was supported by the National Natural Science Foundation of China (Grant No.49474218); The Norwegian MSc-Program financed the stay of Wang Xisheng in Norway for two years. We thank Dr. Harald Walderhaug, Dr. H. Stockhausen, and Dr. F. Hauge
Rock magnetic measurements of Nihewan sediments from Xujiayao section demonstrate that magnetite, hematite and maghemite are dominant remanent magnetization carriers. Monitoring the variations of magnetic susceptibili...