下统 meaning in English

foot length
top to toe /foot

Water invasion bursten out during the railway - tunnel construction is usually the mainly problem in constructing or operating , also which brings surface water to exhaustion and pollutes environment or effects ecology , etc . the geleshan tunnel which crosses through guan - yin gorge anticline which trend is near south north , is located between tuanjie village and jingkou village of the shapingba zone , chongqing city , which is belongs to the inducting segment of yu - huai railway . the guan - yin gorge anticline appears to ridge and slot interlacing in land form , and is composed of clastic rock and carbonate rock from jurassic xintiangou group to triassic
歌乐山隧道位于渝怀线引入段重庆市沙坪坝区团结村至井口村之间，隧道穿越近南北向的观音峡背斜，地貌上表现为脊、槽相间，观音峡背斜由侏罗系新田沟组至三叠系下统碎屑岩和碳酸盐岩组成，歌乐山顶大部分出露可溶岩地层，地表岩溶发育，有大量泉水和暗河出口，并修建有多个中小型水库、大量池塘和水井。