Vegetation and climate during the Late Pleistocene in the northern area of Shaanxi

Aim With the intention to comprehend the evolution characteristics of the prehistoric climate of the late Pleistocene in the middle area of loess plateau.To reveal the changing regularity of the climate.Methods According to the geological investigation,intensive samples were chosen and sporopollen analysis was made on fifty-four samples of the cross section in Shaanxi-Fu County.Results The sporopollen diagram was divided into three different zones is divided.The three zones represent S1,L1 and S0 sedimentary periods respectively.The first zone is combinatorial zone of Corylue-Compositae-Artemisia,with the characteristic that herbaceous plant pollen is predominant and the arbor plant pollen is of high content.The second zone is combinatorial zone of Compositae-Artemisia,with the characteristic that herbaceous plant pollen is predominant and the decrease of arbor plant pollen.The third which is named combinatorial zone of Pinus-Chenopodiaceae-Selaginella tamariscina is marked by the increase of Pinus,Chenopodiaceae,Selaginella tamariscina pollen and the increase of arbor pollen.Conclusion The experiment indicates that the vegetation of S1 sedimentary periods was savannah forest grassland,climate was warm and weter;The vegetation of L1sedimentary periods was dry grasslands,climate was cold and dry;The vegetation of S0 sedimentary periods was forest grassland.climate was warmer,cool and droughty.