Inclination correction for the Moenave Formation and Wingate Sandstone: Implications for North America's apparent polar wander path and Colorado Plateau rotation.

摘要

The ∼201 Ma paleopole for North America is observed in rift basins of the northeastern US, and on the Colorado Plateau (CP). The discrepancy in paleopole positions is attributed to 5° to >10° of clockwise vertical-axis rotation of the CP and inclination shallowing of the paleomagnetism. Inclination shallowing was corrected for the sedimentary rocks of the northeastern US, but not for those from the CP. Vertical-axis rotation of the CP alone cannot reconcile the difference between the paleopoles. Based on high field isothermal remanence anisotropy measurements, the Moenave and Wingate Formations on the CP have experienced inclination shallowing. The corrected paleopole for the CP at ∼201 Ma is 62.5°N, 69.4°E (N=20 sites, alpha95=5.5°), and when rotated about a CP-local Euler pole, there is agreement with the northeastern paleopole. The amount of CP translation based on the corrected rotated paleopole agrees with geological estimates of offset at the eastern CP edge.