PALYNOLOGICAL RECORDS IN THE QANGZÊ SECTION OF THE ZANDA BASIN, NGARI, TIBET

Based on palynological records of the Qangzê section in Zanda basin,Ngari,Tibet,the authors have preliminarily defined the Neogene-Quaternary boundary in the area and revealed the vegetational and environmental history of the area since the late Pleistocene.During~2.68-2.45 Ma,the vegetation was dominated by arbores,mainly Pinus,Chenopodiaceae and Artemisia,indicating a cold warm climate in the mountain region.During~2.45-2.11 Ma,herbs increased rapidly and the climate became dry-cold,indicating the characteristic of the bushveld climate.During 2.11-1.49 Ma,the quantity and species of the herbs reached the culmination and the bush increased accordingly,showing that the climate became more and more arid.During 1.49-1.36 Ma,herbs declined slightly but pteridophytes increased relatively greatly,revealing a dry-cold grassland climate.