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Arid Land Geography ›› 2026, Vol. 49 ›› Issue (8): 1687-1699.doi: 10.12118/j.issn.1000-6060.2025.648

• Earth Surface Process • Previous Articles     Next Articles

Grain-size record of environmental evolution in the Lop Nur in Xinjiang since 33.9 ka BP

YI Tingnan1,2(), CHANG Hong1(), LUO Jiaxin1,2, LONG Xueying1, MA Baocheng1, ZHAO Liangliang1   

  1. 1 State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, Shaanxi, China
    2 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2025-10-18 Revised:2025-11-07 Online:2026-08-25 Published:2026-08-21
  • Contact: CHANG Hong E-mail:yitn@ieecas.cn;changh@loess.llqg.ac.cn

Abstract:

The evolution of the mid-latitude westerly climate system is crucial for understanding interaction mechanisms between high- and low-latitude climate systems. The Tarim Basin, located in the typical arid to semiarid zone influenced by the Northern Hemisphere westerlies, serves as a key region for deciphering the coupling between the North Atlantic and Asian monsoon systems. However, debates remain regarding its moisture-heat configuration patterns and their co-evolution with global climate systems. This study analyzes grain-size fractions from 295 samples of the 0.00-16.10 m sediment core ZK0205 in the Luobei Depression of Lop Nur, Xinjiang, China. Three environmentally sensitive grain-size fractions are identified: Clay (<5 μm), silt (5-63 μm), and sand (>63 μm), which are interpreted as indicators of runoff input, aeolian activity intensity, and strong hydrodynamics, respectively, based on sedimentary characteristics of arid lake basins and modern observational data. Supported by an AMS 14C chronological framework, the environmental evolution of the study area since 33.9 ka BP was reconstructed. The main findings are as follows: (1) The Lop Nur region experienced humid conditions during MIS3, which shifted to arid conditions during MIS2. Overall, the Holocene was characterized by warm and dry conditions, revealing phased changes in moisture-heat configuration on a millennial scale. (2) Comparison between grain-size fraction variations and the Greenland NGRIP ice core δ18O record indicates that the region responded sensitively to Northern Hemisphere millennial-scale climate events. Notably, the response pattern shifted systematically with background climate states (warm periods MIS1/MIS3 against cold periods MIS2). (3) Located at the boundary between the core westerlies domain and its transitional margin, the climate evolution of Lop Nur was constrained by global climatic background conditions and jointly influenced by the westerlies and Asian monsoon systems. This interplay results in high complex regional climatic variability.

Key words: Lop Nur, lacustrine deposit, grain-size analysis, stratigraphic composition, arid Central Asia