甘肃玉门早白垩世野火记录及植被环境演变

早白垩世野火事件频发，陆地环境及植被面貌发生了重大变革，但关于该时期陆地生态环境与野火记录的耦合响应还并不明确。甘肃玉门下白垩统赤金堡组、下沟组及中沟组连续沉积内丰富保存的植物大化石及中-宏观木炭化石，为探索研究区早白垩世植物群演替、古环境变迁及野火记录提供了理想材料。本项目通过对甘肃玉门下白垩统连续沉积内保存的植物大化石及中-宏观木炭化石详细的形态学，解剖学，分类学，有机地球化学，同位素地球化学及煤岩学等方面的分析研究，查明研究区早白垩世植物多样性及植物群演替。在定量化重建研究区早白垩世早期至晚期的古大气、古温度和古降水波动性变化情况及古火灾燃烧温度、频度及强度的基础上，恢复研究区早白垩世的古气候环境变迁及野火演化史，深入探讨研究区早白垩世野火记录与古生态环境演变的耦合关系，为探索白垩纪温室气候变化及陆地生态系统演变提供科学依据。

Wildfires occurred frequently during the Early Cretaceous, and the continental environment and vegetation underwent significant changes. While the coupling responses between the terrestrial ecological environment and wildfire events during the Early Cretaceous are still uncertain. The abundant plant and charcoal fossils in the successive sedimentation of Chijinbao, Xiagou and Zhonggou formations in the Lower Cretaceous of Yumen, Gansu Province provide ideal materials for the studies of palaeo-vegetation succession, palaeo-environmental changes and wildfire events in the study area during the Early Cretaceous. The project mainly focused on the morphological, anatomical, taxonomical, organic geochemical, isotopic geochemical and coal petrological studies of both macro-fossil plants and meso- to macroscopic charcoal fossils collected from the successive deposits of the Lower Cretaceous from Yumen, Gansu Province. The palaeo-plant diversity and palaeo-vegetation succession are studied. Based on the quantitatively reconstructions of palaeo-atmosphere, palaeo-temperature and palaeo-precipitation conditions as well as the combustion temperature, frequency and intensity of the wildfires, the paleoenvironmental changes and wildfire evolution during the Early Cretaceous in the study area are recovered. Therefore, the coupling relationship between the wildfire records and palaeo-ecological environment evolution can be further discussed, providing scientific basis for studying the green-house climate change and terrestrial ecosystem evolution during the Cretaceous.