This paper deals with the Pleistocene strata and their depositional environment on theSongliao Plain of Northeast China by applying determinative and analytic techniques of spore-pollen, magnetic stratigraphy, clay minerals, isotopic dating, sedimentary facies, etc. Resultsshow that the underlying sand gravel layer below 75-80 m in depth in the central plain belongsto the alluvial-lacustrine deposits with a time range of 2.48-1.87 Ma, known as the lowerlimit of the Quaternary. As to the massive clay layer, its lower part, 40-30 m thick, belongsto the middle late period of the early Pleistocene, ranging from 2.01-0.73 Ma, while its upperpart, 25-21 m thick, belongs to the middle Pleistocene, ranging from 0.73-20 Ma, with amean sedimentation rate of 3-4 mm/1000a under the big lake, long-range gentle and steadydepositional environment.
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