南京汤山葫芦洞碎屑堆积地层对比及地貌演化过程重建

Comparison of cave deposit stratum and reconstruction of landform evolution in Hulu cave of Tangshan,Nanjing

南京汤山葫芦洞是著名的南京直立人化石发现地,洞穴碎屑堆积与演化研究是该地点研究中的薄弱环节。本文应用统计学方法分析了该洞穴4个剖面碎屑堆积氧化物和植硅体化石记录,结合洞穴堆积物特征厘清了各剖面间地层对比关系;借助地质雷达等物探技术反演了洞穴东部埋藏堆积的空间结构和特征,进而结合年代学研究成果,将洞穴碎屑堆积自下而上划分为7层,建立了洞穴碎屑堆积剖面与埋藏碎屑堆积间的对比框架。受气候环境演变、洞穴内部动力系统变化以及侵蚀基准面局部调整的影响,洞穴侵蚀堆积的发育可分为洞穴北侧堆积、东部堆积、南裂隙堆积、中部锥状体堆积和西部堆积5个阶段。洞穴演化过程时空上的显著迁移特征及洞穴宜居性差,暗示葫芦洞并非是早期直立人的居住地。

The famous fossil site of Hulu cave in Tangshan,Nanjing,is yielding Homo erectus fossils.Relative to the whole study of Homo erectus in Hulu cave,it is the weak link to study the cave deposit and its evolution.Combining with the achievements in chronology research,this paper analyzes the records of the oxide of cave clastic deposit and the fossils of phytolith from four sections with statistical methods,and clarifies the facts of the stratum contrastive relativation of each section.Besides,with the ground penetrating radar（GPR）method,the spatial structure and characteristic of the deposits of the eastern cave have been renewed,and on the basis of the characteristics of the cave clastic sediments,the constructive framework of the cave sections and cave embedding clastic sediments has been set up.The cave sediments in Tangshan,Nanjing have been identified into 7 layers from the bottom to the top as follows：（1）the lower breccia layer in the bottom of the cave,（2）the earth layer containing the breccia deposit,（3）the mid breccia layer,（4）the clastic earth layer,（5）the upper breccia layer,（6）the clastic clay layer,and（7）the pyramidal clastic breccia layer.Among them,the strata where the No.1 skull of Nanjing Man existed could be re-correlated with Layer ③.As the result of the evolution of paleo-climate and environment,the change of dynamic system of cave inside and the effect of local adjustment of erosion datum plane,the development of Hulu cave sediments can be divided into five stages as follows：（1）the erosion deposit stage of the northern cave,（2）the erosion deposit stage of the eastern cave,（3）the erosion deposit stage of the southern fissure cave,（4）the pyramidal deposit stage of the central cave,and（5）the erosion deposit stage of the western cave.The cave evolution could change with the space-time,and it is not so fit for living,thus it reflects that Hulu cave is not a good place for the ancient people.Based on the above researches,the paper provides the new visual angle and methods to discuss and analyze the evolution of karst cave,living age and environment of Homo erectus in Nanjing and further archeology.