Sedimentary environmental and stratigraphic analysis of the sensitive grain size components from the Dalai Nur Lake deposits, Inner Mongolia

The detailed analysis of lithology, grain size and vertical distribution of the grain-size parameters are made for the samples collected from the sites DL-0 at the northern bank, DL-1 at the central part and DL-2 at the southern bank of the Dalai Nur Lake, Inner Mongolia. The peak values of sensitive grain size components are found to be quite different, indicating the spatio-temporal differences of provenances and sedimentary environments in the above-mentioned well sites. The sites DL-0 and DL-1 indicate stable sedimentary environments while the site DL-2 indicates variable sedimentary environments in which five depositional cycles are recognized. The clay, silt and sand ranging in grain size from 0 to 200 μm occur mostly at the depth of 1.5 m below the lake level of the Dalai Nur Lake. With the increase of the depths, the clay contents increase while the silt and sand contents decrease.