Reconstruction of Climate and Environmental Evolution in the Northeastern Tibetan Plateau Since the Holocene Based on Aeolian Sediments

Abstract

This study aims to elucidate the climatic and environmental evolution and its driving mechanisms in the northeastern Tibetan Plateau since the Holocene. Detailed analysis of the KSH profile, combined with Optically Stimulated Luminescence (OSL) dating and the measurement of environmental indicators, including the mean grain size (Mz) and low-frequency magnetic susceptibility (χ_lf), reveals the characteristics of climatic and environmental changes in this region throughout the Holocene. Further, by comparing the environmental indicators from the KSH profile with summer solar insolation at 65°N, annual precipitation reconstructed from pollen data in Gonghai Lake sediments in Northern China, and the GISP2 δ¹⁸O variation curve from Greenland ice cores, this study categorizes the Holocene climatic and environmental evolution into three stages: a cold and dry early Holocene (11.7-8 ka), transitioning to a warm and humid mid-Holocene (8-4 ka), and returning to a cold and dry climate in the late Holocene (~4 ka to present). The findings indicate that the climatic changes in this area throughout the Holocene are consistent with global climatic trends, with variations in the intensity of the East Asian summer monsoon playing a key role in regional climatic evolution.