Millennial-scale terrestrial weathering history and anthropogenic imprint in an alpine lake from Central Asia: evidence from the sedimentary geochemistry of Lake Sayram
Liu W. Li Y. Ma L. Wang J. Zeng T. Abuduwaili J.
February 2026Elsevier B.V.
Catena
2026#263
The chemical weathering provides crucial information about past climatic variability and anthropogenic impacts. However, records from arid high-altitude regions in Central Asia, remain scarce, limiting our understanding of weathering processes and their forcing mechanisms. We obtained a geochemical record from Lake Sayram in the Tianshan Mountains and reconstructed the millennial-scale weathering history with a multi-proxy approach, including variations of major, trace and rare earth elements, and heavy metal enrichment factors, combined with robust chronological control and advanced statistical methods (locally estimated scatterplot smoothing regression, Wavelet analysis, and the ridge regression-random forest-extreme gradient boost model). The results indicate that physical weathering dominated over chemical weathering, as evidenced by the low chemical index of alteration (mean = 59.76) and low LaN/YbN ratios (mean = 2.75). There were synergistic variations in the enhancement of chemical weathering and the terrigenous debris input during the entire time period studied. The element ratios (Rb/Sr and Al/Ca) primarily indicate that the input of terrestrial detrital material was lower during the Little Ice Age, which was closely linked to the occurrence of weaker runoff. A significant shift occurred after the 1950 s. During this time period, the coupling between the detrital indicators and marked increases in heavy metal enrichment factors (e.g., Pb and As) indicates an intensification of human activities, leaving a distinct geochemical imprint in the lake sediments. The novel application of a combined ridge regression-random forest-extreme gradient boost model outperformed the individual algorithms (R2 = 0.70), offering potential evidence of enhanced weathering trends influenced by anthropogenic forcing. This study reports the first detailed millennial-scale weathering history from an alpine lake in arid Central Asia. The results underscore the increasing intensities of human impacts on Earth surface processes in recent decades and provide a new framework for predicting environmental changes in vulnerable mountain ecosystems.
Anthropogenic impacts , Climate change , Geochemical analysis , Sayram lake sediments , Tianshan mountains , Weathering evolution
Text of the article Перейти на текст статьи
State Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China
Research Center for Ecology and Environment of Central Asia, Chinese Academy of Sciences, Urumqi, 830011, China
University of Chinese Academy of Sciences, Beijing, 100049, China
Xinjiang Key Laboratory of Water Cycle and Utilization in Arid Zone, Urumqi, 830011, China
China-Kazakhstan Joint Laboratory for Remote Sensing Technology and Application, Al-Farabi Kazakh National University, Almaty, 050012, Kazakhstan
State Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands
Research Center for Ecology and Environment of Central Asia
University of Chinese Academy of Sciences
Xinjiang Key Laboratory of Water Cycle and Utilization in Arid Zone
China-Kazakhstan Joint Laboratory for Remote Sensing Technology and Application
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026