Magnetostratigraphy of coastal loess of Dalian, China and its paleoclimatic significance

The section of Yujiawaizi Loess in Dalian, one of the typical sections of China's coastal loess, revealed three reliable polarity reversal events, i.e.,Mungo Event (27.5-23.7 ka BP), Laschamp Event (43.5-37.3 ka BP) and Blake Event (125. 4-110.5 ka BP);while reliability of the fourth one, Gothenburg Event, retrains to be confirmed. Based on TL datings, polarity events and magnetic susceptibility, the authors have tentatively established the time series of coastal loess accumulation since 140 000 a BP, and estimated the accumulation rate of Lt. Meanwhile, the high-resolution magnetic susceptibility curve since 140 000 a BP can be correlated with that of the inland loess in northwest China and δ ¹⁸O curves of polar ice core and deep sea cores, but there are still some differences, representing the particular characteristics of coastal environmental evolution. At last, integrating the polarity strata, magnetic susceptibility and other relative data, the authors have probed into the paleoenvironmental changes since 140 ka BP and climate oscillation cycle of different scale, polarity events and glacial-postglacial climate transition, differences in climate and environment between the early and late stages of last glacial period, and the continuance of coastal loess accumulation.