Preliminary Study of the Olduvai Termination Recorded in the Red Loam in Southeast Shanxi Province, China

Abstract

The Olduvai termination record recovered from remanent magnetization of the Red Loam has demonstrated the possibility of recording and preserving the geomagnetic polarity transition in eolian deposits and displayed some characteristics different from those of the Olduvai termination records available. The paleofield direction undergoes three phases of change during the polarity transition. In the first phase, only the declination changes, resulting in the VGP's moving along a meridional band, bounded by 30°E-150°W and 50°E-130°W, in high northern latitudes. The following phase is characterized by swift change in both declination and inclination. The VGPs move to the far hemisphere, migrate southerly, and come back to the near hemisphere at moderate southern latitude. A smooth approaching to the expected reverse polarity-like direction constitutes the third phase. The estimated durations of these three phases are 8900, 5300, and 6600 years, respectively. The VGP path is longitudinally confined and strongly near- and west-sided.