湘桂黔滇藏一线覆盖型岩溶地貌特征与岩溶(双层)夷平面

FEATURE AND ORIGIN OF COVERED KARST ON HUNAN,GUANGXI, GUIZHOU,YUNNAN AND TIBET

根据岩溶风化壳的发育条件及研究区覆盖型岩溶特征 ,提出岩溶 (双层 )夷平面概念 ,认为研究区覆盖型岩溶是一个统一的岩溶 (双层 )夷平面的组成部分。其现阶段的存在形式如石林、岩墙等为后期不同程度风化 -刻蚀作用的结果 ;其地貌形态多为土下成因 ,并随剥蚀程度。

In light of the formation conditions of karst weathering crust and the characters of the red weathering crust and the covered karst on research district,this paper suggests a new concept of weathering crust and geomorphologic evolution stage.Since the thick and continuous weathering crust is only formed on base level of erosion,it indicates existence of the planation surface mentioned above.The double leveling surfaces of karst planation is made up of thick weathering crust and covered karst.Thereby the covered karst also indicates the existence of the monitioned surfaces of karst planation just like the weathering crust.Authors believe that the double leveling surfaces of karst planation exists at overall study region,and the covered karst is itsown base weathering front according to characters of the covered karst and the weathering crust of this district.Present forms of covered karst on research area,such as stone pinnacles and rock wall,are just the result of etching to various degrees.These type of covered karst have the same subsoil features and also have the reworked subaerial characters that varies from west to east alone with the etching degree,surface exposure time and environment.