Progress and outlooks on magnetostratigraphy of Chinese loess

The Chinese loess is one of the most important terrestrial records of the Quaternary climate changes. Magnetostratigraphy is one of the primary methods for establishing the chronological framework of the Quaternary loess. The measured positions of the Brunhes/Matuyama, Jaramillo, Olduvai, and Matuyama/Gauss polarity reversal boundaries in Chinese loess were summarized and compared against corresponding marine records. It was found that the positions of each polarity reversal boundary are inconsistent among different loess sections, and the difference spanned more than one loess-paleosol cycle. This discrepancy cannot be attributed to the lock-in effect, regional climate, sedimentation rate or different loess stratigraphic divisions. This may indicate that the polarity reversal boundaries recorded by loess deposits had probably experienced significant remagnetization, leading to a large discrepancy between loess geochronometer in magnetostratigraphy at orbital scale and marine oxygen isotope records by different researchers. In the future, studies shall focus more on the relative paleointensity (RPI) of loess to confirm the true position of each polarity reversal boundary and ultimately resolve the discrepancy in the comparison scheme between Chinese loess data and deep-sea sediment record.