南京汤山地区的地貌与岩溶发育演化

岩性和构造控制了南京汤山地区的地貌格局和碳酸盐岩山地岩溶地貌发育。研究表明,汤山地区岩溶演化具有长期性、多代性和继承性的特点,石炭纪中晚期及此前发育了第一期岩溶洞穴,三迭纪末至早侏罗纪是古岩溶最为发育的时期,晚第三纪以来进入了现代岩溶发育阶段。著名的南京直立人洞穴形成于晚第三纪之后。

Evolution of Landform and Karst Development in Tangshan, Nanjing

Lithological character and geologic structure determine the landform pattern and its evolution in Tangshan area,Nanjing.Through studying the evolution course of the karst physiognomy in Tangshan area,this paper shows that the karst evolution in this area is marked by protracted nature,multi-era and inheritance.In the Paleozoic the paralic transition was the main characteristic.The karst cave in the first stage was developed in the middle-late Carboniferous and heretofore.In the Mesozoic the folding block-fault mountain and basin were developed.Among them,the palaeokarst was fully enriched from the ending of Trias to Lias.The differential uplifting mountains came into being in the Cenozoic.Since the Neogene period,the modern karst development stage began to occur.As the karst evolution in Tangshan area has the characteristics of complexity and inheritance,and in the karst cave of vertical distribution,there exists the intercrossed and superimposed caves,which were formed in the different stages.Moreover,the karst caves had gone through many changes in the different stages so that their original height sequence were possiblly changed,thus the height of the caves was not regarded as the only criterion to judge their ages. The well-known homo erectus cave in Nanjing is possible related with the fully enriched palaeokarst from the end of Trias to Lias,the principal part of which could be seen at present was mainly formed in the Neogene period.The cave came into the physical infilling stage in the Middle Pleistocene.The entrance of the cave began to block in till the initial stage of the Late Pleistocene and took the chemical deposit as the dominant factor.Therefore,it can be seen that the well-known homo erectus cave in Nanjing came into being after the Neogene period.