摘要
通过野外观察研究,在黄河晋陕峡谷段柳林县三川河支流沟口内,发现了疑似全新世黄河古洪水滞流沉积层剖面。根据磁化率、烧失量、Ca CO3、粒度成分测定的实验结果可知,四层沉积物磁化率、烧失量较低,Ca CO3含量较高;结合野外观测、粒度特征分析、C^M图和粒度分布频率曲线,表明四层河流沉积物具有典型的古洪水滞流沉积层(SWD)特征。通过地层分析和OSL测年,证明在距今3 200~2 900年前,黄河晋陕峡谷经历了一个洪水期,发生了多次大洪水事件,此时正值我国历史的商末—西周初期,造成了社会动荡和历史转折。该研究结果揭示了古洪水SWD的基本特征,为晋陕峡谷特大古洪水事件洪峰水位和流量的恢复,黄河水资源开发、防洪减灾和水土保持都奠定了科学基础,对揭示区域气候水文变化与全球变化的响应规律有着非常重要的科学意义。
Suspected Holocene palaeoflood slackwater deposits（ SWDs） were identified in Liulin County along the Shanxi-Shaanxi Gorges in the middle reaches of the Yellow River. Samples were collected and magnetic susceptibility,loss-on-ignition,calcium carbonate and grain-size distribution were measured in the laboratory. The results showed that the four layers of SWDs had high values in the calcium carbonate and low values the magnetic susceptibility and loss-on-ignition. The four layers of SWDs had a typical characteristics of palaeoflood SWDs according to field research,analysis of grain size feature,C-M pattern and frequency of grain size distribution.,Using the Stratigraphic subdivisions and OSL dating methods,this study demonstrated that the Jin-Shan Gorges of the Yellow River experienced a flooding period in 3 200- 2 900 years ago. Repeated big flood events caused the social instability and marked a turn point in history when it was at the period between the early Western Zhou dynasty and the late Shang dynasty. The study revealed the basic characteristics of the palaeoflood slackwater deposits,which was of significance to reconstruct the Holocene Palaeoflood flood events,mitigating flood disasters and conservation of soil and water. These finding were important in understanding the interaction between regional hydrological system and global climate change.
出处
《干旱区研究》
CSCD
北大核心
2015年第1期198-204,共7页
Arid Zone Research
基金
国家自然科学基金重点项目(41471071)
教育部博士点基金优先发展领域项目(20110202130002)资助
关键词
古洪水
滞流沉积物
全新世
晋陕峡谷
黄河
palaeoflood
slack water deposits
Holocene
the Jin-Shan Gorges
the Yellow River
