The boundary of the Matuyama-Brunhes paleomagnetic polarity reversal (MBB) is recorded in the marine isotope stage (MIS) 19 in the marine sediments, corresponding to an interglacial period. However, most of the previous loess reports about the MBB displayed that it is recorded in the eight loess horizon (L8, a glacial period). This discrepancy was interpreted as the large scale lock-in depth of the natural remanent magnetization in the Chinese loess, however, another point claimed that this phenomenon may be caused by the phase lag of the climate between loess and marine sediments.

In this study, we have measured five sets of parallel samples from the L8+S8 of the Mangshan section in the Henan province. The thickness of the MBB has been accurately determined using our previous analysis method (JGR paper, 2010). After correlations of the climatic parameters between the Mangshan and Luochuan sections, associated with the division of the lithologic stratigraphy in the field, the MBB was located in the transitional zone from S8 to L8, but not singly in L8 or S8. This discovery can be used to interpret the inconsistence of the location of the MBB in sections from the Chinese loess plateau. An inaccurate definition of the MBB due to the large sampling interval (>20 cm) in previous magnetostratigraphy reports may be one possible cause to the confusion, associated with the division of the climatic stratigraphy. Our conclusion further demonstrates that L8 and S8 should be correlated to MIS 18 and 19.