The discovery of the sporopollen fossils from the Middle Jurassic Yangye Formation in Qiemo area of Xinjiang and its geological significance

Abundant sporopollen fossils, which include 37 genera and 81 species, were found for the first time in the Yangye Formation in Jiangalsay, Qiemo, Xinjiang. According to the characteristics and stratigraphic distribution of sporopollen fossils, the age of the Cyathidites-Neoraistrickia-Disacciatrileti belongs to the early stage of Middle Jurassic. The palynological assemblage is well correspondent to that of some regions in Northwest China and North China. By studying the kinship between the sporopollen components and vegetation types, the authors have reached the conclusion that the vegetation at the early stage of Middle Jurassic was mainly composed of Filicinae, lycopods conifers and cycad in Jiangalsay, which suggests that the paleclimate belonged to the tropicalsubtropical humid climate.