We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
In‐Situ Silt Generation in the Taklimakan Desert Evidenced by Uranium Isotopes.
- Authors
Li, Le; Zhu, Xiaoyu; Li, Gen K.; Liu, Lianwen; Xu, Zhiwei; Lu, Huayu; Fang, Xiaomin; Song, Yougui; Zhao, Liang; Chen, Jun; Li, Gaojun
- Abstract
Understanding the mechanism of dust generation is critical for evaluating the global cycles of nutrient elements and for interpreting paleorecords derived from aeolian deposits. Here, we use a novel geochemical tracer, the 234U/238U activity ratio that reveals particle comminution age, and Sr‐Nd isotopes to investigate how silt‐sized particles are produced in the Taklimakan Desert, a major dust source region having effects on global ecosystems. Based on the results from 20‐ to 25‐μm size fractions, we find that approximately 40% of the Taklimakan Desert silts and approximately 30% of the silts in the aeolian dust flux from the area are produced by in‐situ desert processes (e.g., abrasion). The silt‐sized materials in the Taklimakan Desert are mainly sourced from the eastern Kunlun Shan and are unlikely to be a major source of the Chinese Loess Plateau. Our findings demonstrate the importance of in‐situ desert processes in producing silt‐sized particles, providing new insights into the global dust cycle. Plain Language Summary: The provenance of silt‐sized particles in the Taklimakan Desert is critical for understanding aridification and climate dynamics in central Asia, as well as the production mechanism of dust—a key player in the global biogeochemical cycles of nutrient elements. Here, we measured the uranium‐strontium‐neodymium isotopes in silt‐sized particles from the Taklimakan Desert and the adjacent mountains to understand the source, production, and transport of dust in the region. The uranium isotopes record the timespan since particles were separated from the bedrock and are independent of bedrock composition. Our results indicate that the silt‐sized materials in the Taklimakan Desert are mainly sourced from the eastern Kunlun Shan, with partial contribution from the Pamir mountains. The isotopic evidence weakens the possibility that the Taklimakan Desert is a major source of the Chinese Loess Plateau. We found that besides mountainous (fluvial and glacial) processes, in‐situ desert processes (e.g., abrasion) produce a significant amount of the silts in the Taklimakan Desert and the aeolian dust flux from the Tarim Basin, which gets transported by the westerly jet and influences global ecosystems. These findings shed new light on dust production and transport in arid areas. Key Points: We use U‐Sr‐Nd isotopes to investigate the sources and production mechanism of the silts in the Taklimakan Desert in Northwest ChinaIn‐situ desert processes (e.g., abrasion) are important mechanisms for producing silt‐sized particles in the Taklimakan DesertThe Taklimakan Desert silts are mainly sourced from the eastern Kunlun Shan and are not a major source of the Chinese Loess Plateau
- Subjects
KUNLUN Mountains (China &; India); URANIUM isotopes; NEODYMIUM isotopes; DESERTS; SILT; NUTRIENT cycles; BIOGEOCHEMICAL cycles; JET transports; CHINESE language
- Publication
Journal of Geophysical Research. Atmospheres, 2022, Vol 127, Issue 17, p1
- ISSN
2169-897X
- Publication type
Article
- DOI
10.1029/2022JD036435