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在黄河源区支流日玛曲河谷发现第四纪湖相沉积,以含砾粉砂、粉砂、粘土互层组合为特征,形成河流的第一阶地基座。通过对该剖面野外岩性观测1、4C测年分析,探讨了古湖形成时代及成因,以及古湖发育时期周围的植被与环境。研究结果发现,古湖形成于3 120aBP前后,可能属于地震堰塞湖,于640aBP以后出现决堤事件。
Quaternary lacustrine sediments were discovered in the Rih Maqu River valley, a tributary of the source region of the Yellow River, characterized by interbedded layers of gravelly silt, silt and clay, forming the first basement of the river. Based on the 1, 4 C dating analysis of the field lithology observation in the section, the formation age and genesis of the ancient lake and the vegetation and environment around the ancient lake development stage were discussed. The results show that the ancient lake formed before and after 3 120aBP may belong to the earthquake dammed lake, after 640aBP burst event occurred.