Abstract:

The special Pleistocene strata were formed by the differential tectonic activities in Eastern Songliao Plain during the Quaternary period. Due to the difference of Quaternary strata division and the differential strata in different regions, the stratigraphic boundary between Middle and Upper Pleistocene series was not determined in Eastern Songliao Plain. Studies of the Fangzheng strata profile in Heilongjiang Province, the age of (149.6±10.4) ka by optically simulated luminescenc, the analysis of main elements, trace elements, REE as well as the correlation of strata profiles indicate that taking 140 ka as the stratigraphic boundary between Middle and Upper Pleistocene series is suitable for the strata reality situation. The Middle Pleistocene strata are composed of the sediments of stream, lake and flood facies. Late Pleistocene strata are dominated by the lower part of the limnetic and floodfacies clay and upper part of loess. The limnetic and flood facies clay may be lack in the strata profiles of the Huangshan Formation because of the facies transformation. The Fangzheng strata profile can correlate with the Donggang profile in Yushu County. The depositional environment changed obviously in middle and Late Pleistocene. Contents of main elements, trace elements, REE appeared prominent changes between Middle and Upper Pleistocene series.