Preliminary application of palynological quantitative method in the reconstruction of Quaternary paleoclimate in Dongting Basin

Quaternary climate change is currently one of the research hotspots in geoscience. Dongting Basin in the middle reaches of the Changjiang (Yangtze) River is one of the most representative Quaternary sedimentary basins in South China. Its paleoclimate records are of great significance for understanding regional and global climate evolution. However, available studies still face limitations in temporal resolution and regional comparability. We utilized pollen data from the ZKC01 borehole in Lianghu Village, Hanshou County, Changde City, Hunan Province, and applied the Modern Analogue Technique (MAT) for quantitative analysis to reconstruct the paleotemperature and paleoprecipitation sequences of the basin during the Quaternary. Results indicate that the Quaternary climate of the basin underwent significant phased changes, including the Plio-Pleistocene intensification of Northern Hemisphere glaciation (iNHG, approximately 2.6～2.5 Ma), an early Pleistocene arid period (approximately 2.6～2.2 Ma), two superinterglacial periods during the Gelasian and Calabrian stages (approximately 2.2～2.0 Ma and 1.6～1.5 Ma, respectively), the Zhonglianggan Glaciation and the Last Glaciation. These findings not only refine the high-resolution record of Quaternary paleoclimate evolution in Dongting Basin but also provide critical insights into the response mechanisms of regional climate to global changes.