临汾盆地晚冰期至中全新世黄土-古土壤序列的风化特征及指示的气候意义

了解中国北方晚冰期和全新世时期的气候环境变化及其驱动机制，有助于预测未来气候变化的可能情景。基于黄土高原东南缘临汾盆地的黄土-古土壤剖面，在3个AMS14C年代的支持下，通过粒度、磁化率、土壤有机碳以及地球化学元素等指标，重建了临汾盆地晚冰期至中全新世晚期的气候变化历史。结果表明：宋村沟剖面的黄土和古土壤分别处于初等和中等化学风化阶段，而不同地区风成堆积物的化学风化强度存在明显差异，主要受控于东亚夏季风的区域变化。多指标综合分析表明，晚冰期以来临汾盆地的气候演变经历了4个阶段：晚冰期东亚冬季风较强，气候干冷；早全新世东亚夏季风强化，气候向暖湿转变；早中全新世东亚夏季风达到峰值，为最暖湿的适宜期；中全新世晚期东亚夏季风减弱，气候再次转向干冷；临汾盆地的气候变化主要受控于北半球太阳辐射强度和冰量的变化。

Characteristics of weathering of the loess-paleosol sequences in the Late Glacial Period to Middle Holocene in Linfen Basin and implication for climatic significance

Exploring the climate and environmental changes and the driving mechanisms during the Late Glacial and Holocene in the northern China is vital to predicting the possible scenarios of future climate change. Based on the loess-paleosol profile of Linfen Basin in the southeastern margin of the Loess Plateau, we analyzed three AMS14C dates, grain size, magnetic susceptibility, soil organic carbon, and geochemical elements, and reconstructed the climate change history of Linfen Basin from the Late Glacial Period to the middle and late Holocene. Results show that the loess and paleosol of the Songcungou section are in the early and middle chemical weathering stages, respectively. The chemical weathering intensity of aeolian deposits in different areas was obviously different, which is mainly controlled by regional variation of the East Asian Summer Monsoon (EASM) intensity. Comprehensive analysis of multiple indicators shows that climate evolution of the Linfen Basin has experienced four stages since the Late Glacial Period. (Ⅰ) In the Late Glacial Period, the East Asian Winter Monsoon (EAWM) was strong, and the climate was dry and cold. (Ⅱ) In the early Holocene, EASM was intensified and the climate became warm and humid. (Ⅲ) In the early Middle Holocene, EASM reached its peak, and the climate was warmest and wettest. (Ⅳ) In the late Middle Holocene, EASM weakened and the climate turned dry and cold again. The climate change in the Linfen Basin was mainly controlled by the changes of solar radiation intensity and ice volume in the Northern Hemisphere.