In north China, the thickness of Ordoviciansystem is larger, the water-abundance is better.
华北地区奥陶系厚度大,富水性强。
2
A large amount of first hand data have been gained by the field investigation of the carbonate karst of the Ordoviciansystem in the Xishan Hill of Beijing.
通过对北京西山奥陶系碳酸盐岩岩溶的野外调查,取得了大量的第一手资料。
3
There is a normal deposition sequence stratigraphy beneath the lower wall of over-thrust fault, such as Jurassic, Triassic, Permian-Carboniferous, Cambrian-Ordoviciansystem.