Abstract:

During the study of karst seepage for the upstream bay area on Loushui River，in the boundary between Hunan Province and Hubei Province，the huge ancient landslide and dammed lake were found and studied.The paper stated the landslide and dammed lake in brief，and discussed and analysed some problems about them.The landslide body is about 20 million cube，and the dam is about 1000 m long.The total thickness of the clay is more than 48 m，and the highest point of the clay laying out is 284.1 m height about sea level.The 14C ages is about 10760±130 aBP and 16880±250 aBP for the upper and lower clay.It is considered that the level of the lake is more than 285 m.The high sulphate content of the groundwater flowing out from the clay is not associated with the environment of clay deposit and the clay itself.The clay trend in two bank of the river is possible made by the relandslides.This result is of reference value for water and electricity engineering construction，and for the study of the development history of Loushui River and the formation and evolution of calamitous geological hazards of today's rivers.