摘要
以亚洲季风边缘Ⅸ佰羊河流域终端湖猪野泽为例，结合最新的沉积物年代、岩性、指标及古湖泊岸堤研究结果，从时间和空间尺度上探讨了猪野泽中全新世丁早事件时空范围和机制。从空间上对比了猪野洋中全新世地貌及沉积物岩性和指标，并配合石羊河中、上游地区的中伞新世沉积剖面进行研究。在时间尺度上分析了猪野泽和石羊河流域近百个全新世测年结果，最终得出猪野泽地区存8．0～7．0calkaB．P．期间存存百年尺度的干早事件，而小足以前研究提出的距今7000～5000日历年期问2000a尺度的干旱事件，并日．这次极端十旱事件影响范围主要存行羊河中、下游地区，对石羊河上游地区影响较小。根据时窄尺度分析对猪野泽中拿新世，‘早事什机制进行讨论，结果表明这次干旱事件主要足…流域气候条件特征和水热配比改变所引起的，而不是以前研究提出的业洲夏季风减弱导致。
In this paper, the sediments and paleo-lakeshores data in Zhuye Lake and surrounding areas, the terminal lake of Shiyang River drainage basin, in the marginal area of the Asian monsoon, were synthesized arid then the spatial and time scales around Zhuye Lake and in the drainage basin were discussed. In the spatial scale, this study compared the results＇ of mid-Holocene geomorphology and lake sediments in Zhuye Lake, and we also studied the mid-Holocene sections in themiddle and upper regions of the Shiyang River. In the time scale, nearly a hundred dating results in Zhuye Lake and the drainage basin were compared. Then it was coneluded that there was a centennial-scale extremely dry interval occurring during 8.0-7.0 cal ka B.P. in Zhuye Lake, instead of the previous study which reported the dry interval during 7000-5000 cal a B.P.. And the centermial-scale extremely dry could be detected in the middle and lower reaches of the drainage basin, but the upper region was less affected. The centennial-scale extremely dry interval might be related to the changes in water and heat balance, and the characteristics of climatic conditions in this drainage lead to the different responses to the dry interval in the different locations of the drainage basin. There were no obvious evidences showing that the dry interval was related to the Asian monsoon weakening. In this paper, the time and spatial scales analysis of the dry mid-Holocene in Zhuye Lake provide some clues and ideas for the dry mid-Holoeene studies in other parts of the Asian monsoon domain.
出处
《地理科学》
CSCD
北大核心
2012年第6期731-738,共8页
Scientia Geographica Sinica
基金
国家自然科学基金(41001116)
兰州大学中央高校基本科研业务费专项资金项目(LZUJBKY-2010-99)资助
