DETAILS OF MAGNETIC POLARITY TRANSITION RECORDED IN CHINESE LOESS

The paleomagnetism of the loess unit L8 in Xifeng section of the Chine se Loess Plateau has been studied to determine the behavior of the Mat uyama-Brunhes transitional field. Three primary results have been obta ined. (1) The M-B transition is located in the low part of L8 and the time duration of this transition defined by directional changes is est imated to be about 3,600 yrs, whereas the intensity changes last about 8,000 yrs, both of the estimations being based on the SPECMAP delta-O -18 time scale (IMBRIE et al., 1984). (2) The morphology of the M-B tr ansition field is characterized not by a single reversal course, but a t least by three reversals and one aborted reversal course. The VGP pa ths obtained are not consistent with a non-dipole axisymmetric field. (3) The geomagnetic fields during this transition seem to have the con figurations that dipole field component is at least comparable to the non-dipole ones in magnitude, which does not support the commonly-acce pted viewpoint.