New Cambrian paleomagnetic pole for Yangtze Block

A total of 120 samples from 12 sites were collected from two flanks of a fo ld. Stepwise thermal demagnetization has successfully revealed characterist ic magnetization components from the rocks in each case. a well-defined com ponent determined from red fine-grained sandstone is clustered in the north easterly direction with shallow upward inclination (D = 29.3 degrees, I = - 19.2 degrees, k = 283.7, alpha(95) = 7.3 degrees, tilt-corrected). The pole position (39.5 degrees N, 247.3 degrees E, dp = 4.0 degrees, dm = 7.6 degr ees) derived from this component is dose to the Permian pole for the Yangtz e Block, indicating that the red fine-grained sandstone has been overprinte d. The red mudstone reveals two characteristic components. Component A with lower unblocking temperature, characterized by northerly declination and m oderate to steep inclination, corresponds to a pole position overlay with t he present North Pole. Component B (D = 129.1 degrees, I = -23.6 degrees, k = 44.6, alpha(95) = 7.8 degrees, tilt-corrected) with higher unblocking te mperature, passes fold test, and yields a pole position (39.5 degrees S, 18 5.1 degrees E, dp = 4.4 degrees, dm = 8.3 degrees) different from the other poles for the Yangtze Block. It is therefore suggested that component B wa s probably a primary magnetization and the Yangtze Block was situated at lo w latitudes in the Southern Hemisphere in the Middle Cambrian.