基于孢粉数据的白垩纪中国东部地貌解读OA北大核心CSTPCD

A series of tectonic movements during the Late Mesozoic greatly changed the topography and landform in eastern China,forming a geomorphic pattern of"high in the east and low in the west".There is still a controversial issue on the existence of plateaus or mountains in eastern China during the Cretaceous,and thus the evolutionary processes,paleoaltitude and the extensional range of plateaus or mountains need further studies.In this paper,we collected the palynological data of xerophyte and disac-cate pollen from vorious localities of China during the Cretaceous,and further discussed the paleovegeta-tion succession and palaeoclimate evolution,which provides paleontological evidence for the interpretation of the geomorphology in eastern China at that time.The result shows that there were three climate zones in China during the Cretaceous:(i)the northeastern region was a warm and humid subtropical-warm climate zone;(ii)the northern region was a semi-arid tropical-subtropical transitional climate zone;(iii)the Tibet,Xinjiang and southern China were a hot and tropical-subtropical climate zone.The interpretation of the geomorphology shows that there was a high-altitude landform in northeast China during the early Early Cretaceous.Additionally,it is likely that coastal mountains existed in the Fujian and Zhejiang regions dur-ing the Early Cretaceous.In early Late Cretaceous,the range of coastal mountains in eastern China reached its maximum.From the late Late Cretaceous to Early Paleocene,the mountains in eastern China gradually collapsed,and by the Early Paleocene,the mountains were probably disappeared.