Abstract
Hyperarid climate and salty lakes prevail in the current Qaidam Basin, but this basin was once a large paleolake until the early Quaternary. However, its evolution history and relationship with climate and tectonics are still elusive. Here we present detailed stratigraphic descriptions combined with total organic carbon content and weight ratio of organic carbon to total nitrogen records from fluvio-lacustrine sediments in the western Qaidam Basin to infer how the lake evolved during the late Pliocene-early Pleistocene. These data reveal a drying trend since 3.3 Ma, which we attribute to low latitude forcing and/or local tectonic activities. However, this trend was interrupted during 2.84–2.48 Ma, in which climate wetting was observed. We attribute the climate wetting during 2.84–2.48 Ma to intensified East Asian summer monsoon as is documented by the Chinese Loess Plateau records. Halite and gypsum content increased dramatically after 2.5 Ma, indicating the formation of salty lake in the western Qaidam Basin. These data improve our understanding of the detailed processes of Qaidam aridification and its potential forcing mechanisms.
Highlights
The Qaidam Basin (QB), with an area of ∼80,000 km2 and an average elevation of ∼2.7 km above sea level, is the largest internally drained basin on the northeastern Tibetan Plateau (Fang et al, 2007)
total organic carbon (TOC) coupled with carbon to total nitrogen (C/N) ratio in fluviolacustrine sediments is sensitive to lake shrinkage and expansion and has been widely used to reflect variations of terrestrial input relative to lake productivity (Liu et al, 2013; Fan et al, 2017)
Multiple-proxy records of the western Qaidam Basin lake evolution
Summary
The Qaidam Basin (QB), with an area of ∼80,000 km and an average elevation of ∼2.7 km above sea level, is the largest internally drained basin on the northeastern Tibetan Plateau (Fang et al, 2007). The basin is largely covered by dry salt playas, with only minor desert vegetation and hypersaline lakes (Wang et al, 2012). Due to the scarcity of continuously dated sediment records (Lu et al, 2015; Fang et al, 2016), how the Qaidam paleolake evolved into its hyperarid condition remains relatively unknown. Lack of such records prevents understanding the underlying forcing mechanisms for Qaidam drying and central Asian aridification
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
