Holocene precipitation change in an East Asian sandy land: Perspectives from the grain size records of multi-sections

Abstract

Integrating multiple climate proxies is vital for advancing regional climate reconstruction. This study minimizes uncertainty among records by analyzing four aeolian-paleosol profiles (ADQ, HTGL, MJ, FX) within China's Horqin Sandy Land, using grain size as the primary climate proxy. Initially, end-member analysis was employed to separate the end-member components from the different profiles. By combining topsoil particle size data and modern meteorological monitoring data, the relationship between coarse-grained components and climate factors was established, providing strong evidence for the coarse-grained end-members in the sections that represent regional climate change. Based on this, we employed the regional averaging method to extract regional climate signals represented by coarse-grained end-member components from various profiles. Simultaneously, by integrating the locations of each profile with records of human activities, we investigated whether these climate signals were influenced by local signals. The results indicate that the regional climate signals derived from multiple profiles (grain size range: 77.77–566.88 μm) accurately reflect a precipitation trend in the region during the Holocene, which initially increased and then decreased. Furthermore, the end-member components representing regional climate signals in profiles from different locations may be affected by human activities and natural environmental factors, leading to the contamination of these signals with their respective local environmental signals.