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风尘是地球表层系统的重要组成部分,广泛参与地球系统中不同时空尺度的物理、化学和生物过程,对全球气候和生态环境产生重要的影响。中国北方地区发育了世界最广、最厚的风尘沉积,记录了至少22 Ma以来东亚季风演化和亚洲内陆干旱化历史。半个多世纪以来对风尘沉积的气候记录和黄土高原的成因进行了大量研究并取得了丰硕成果,然而对黄土高原风尘物质沉积过程的认识还存在很多问题。例如,近年来基于物源示踪研究对传统的风尘搬运过程提出了新认识,认为虽然黄土主体是风成的,但以前忽略了河流对于碎屑物质的搬运贡献。我们在前人研究基础上从沉积学角度分析风尘沉积过程,发现青藏高原两期抬升与区域构造运动对粉尘沉积起着不亚于气候变化的重要控制作用;同时从沉积-侵蚀和地貌发育过程探讨风力与流水这两种最常见的外动力方式在黄土沉积和黄土高原发育过程中所起的作用,认为风尘的沉积和黄土高原的形成是侵蚀与搬运沉积作用的长期动态平衡过程,风力和流水在其中所起的作用都不是单一不变的,在不同时期和不同区域有可能会同时充当建设者和破坏者的角色。
Dust is an important part of Earth’s surface system and its extensive participation in the physical, chemical and biological processes at different time and space scales in the Earth system has an important impact on the global climate and ecological environment. The northern part of China has developed the most extensive and thickest dust deposits in the world, recording the history of the evolution of the East Asian monsoons and the arid inland in Asia since at least 22 Ma. For more than half a century, a great deal of research has been done on the climatic records of aeolian dust deposition and the genesis of the Loess Plateau. However, there are still many problems on the understanding of dust deposition in the Loess Plateau. For example, in recent years, based on the provenance tracing study, a new understanding of the traditional dust-dust handling process has been put forward. Although the main body of loess is extremely successful, the river’s contribution to debris transport has been neglected. Based on the previous studies, we analyze the dust deposition process from the perspective of sedimentology. It is found that the uplift and regional tectonic movement of the Qinghai-Tibet Plateau plays an important role in controlling dust deposition as much as climate change. From the sedimentation-erosion and topographic development This paper discusses the role of wind and flowing water, the two most common external dynamic modes, in loess sedimentation and the development of the Loess Plateau. It is concluded that the deposition of dust and the formation of the Loess Plateau are the long-term dynamic equilibrium processes of erosion and sedimentation, The role of flowing water in them all is not unalterable. In different periods and in different regions, it is possible to act as both a builder and a saboteur.