Characteristics of ancient Aniangzhai barrier lake in upper reaches of Dadu River
The examination of the sedimentary characteristics of ancient barrier lakes provides the foundation for research on the ancient environment and climate.A section of a barrier lake containing silty clay,sand,and gravel has been exposed on both sides of Xiaojinchuan in the upper reaches of the Dadu River.The results of sediment analysis,photoluminescence dating,and investigations into the lithology and structure of the barrier dam suggest that a major river-blocking dam collapse event occurred in Xiaojinchuan during(15.7±1.9)～(9.1±1.0)ka,and caused the sedimentary environment of the ancient barrier lake to migrate over time.The barrier lake has undergone three stages of filling and collapse during its formation over time.Its four sedimentary areas can be divided from downstream to upstream into deep to semi-deep lake,shallow lake,riverside lake,and the area of intersection between river and lake.This ancient barrier lake was formed by the blockage of the river by the ancient Aniangzhai landslide,and is named after it.The ancient landslide was mainly controlled by the lithology and tectonic processes in the area.The work here enriches research on large-scale ancient barrier lakes in the mountainous areas of southeastern Tibet,and provides materials for subsequent examinations of their sedimentary characteristics,age,and genetic characteristics.
万方数据
维普
