Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, 730000, Lanzhou, China.
Centre for Environmental Geochemistry, School of Geography, University of Nottingham, Nottingham, NG7 2RD, UK.
Nat Commun. 2023 May 29;14(1):3102. doi: 10.1038/s41467-023-38828-4.
How climate change in the middle to late Holocene has influenced the early human migrations in Central Asian Steppe remains poorly understood. To address this issue, we reconstructed a multiproxy-based Holocene climate history from the sediments of Kanas Lake and neighboring Tiewaike Lake in the southern Altai Mountains. The results show an exceptionally warm climate during ~6.5-3.6 kyr is indicated by the silicon isotope composition of diatom silica (δSi) and the biogenic silica (BSi) content. During 4.7-4.3 kyr, a peak in δSi reflects enhanced lake thermal stratification and periodic nutrient limitation as indicated by concomitant decreasing BSi content. Our geochemical results indicate a significantly warm and wet climate in the Altai Mountain region during 6.5-3.6 kyr, corresponding to the Altai Holocene Climatic Optimum (AHCO), which is critical for promoting prehistoric human population expansion and intensified cultural exchanges across the Central Asian steppe during the Bronze Age.
全新世中晚期气候变化如何影响中亚草原早期人类迁徙仍不甚清楚。为解决这一问题，我们重建了南阿尔泰山喀纳斯湖和相邻铁外克湖沉积物中的全新世气候历史。结果表明，硅同位素组成（δSi）和生物硅（BSi）含量表明，在约 6.5-3.6 千年前存在异常温暖的气候。在 4.7-4.3 千年前，δSi 的峰值反映了湖热分层的增强和周期性的营养限制，同时 BSi 含量下降。我们的地球化学结果表明，在 6.5-3.6 千年前，阿尔泰山地区气候显著温暖湿润，对应于阿尔泰山全新世气候最优期（AHCO），这对促进青铜时代中亚草原史前人口扩张和文化交流的加强至关重要。
