粤北金鸡岭丹霞地貌发育与地质构造的关系

THE DEVELOPMENT OF DANXIA LANDFORM IN JINJILING DISTRICT,NORTH GUANGDONG,AND ITS RELATIONSHIP TO GEOLOGICAL STRUCTURE

本文讨论了粤北金鸡岭地区各种破裂构造的特征及其与该区丹霞地貌发育的关系。研究结果表明,近东西向和近南北向的两组构造破裂面控制着该区条、块、面、线和点五种地貌形态的发育,而层状洞穴的发育则与成岩节理有关。沿着构造破裂面的机械崩塌、化学溶蚀和流水冲刷是形成金鸡岭丹霞地貌的三种主要地质作用。通过对各种实际资料的归纳和抽象,笔者还初步建立起金鸡岭丹霞地貌的演化模式,并得出该区丹霞地貌目前整体处于壮年期的认识。

Two sets of fractures,one trending approximately from west to east and the other approxi-mately from north to south,were recognized in the Jinjiling district of North Guangdong,and the fractures were found as the basement of development of the Danxia landform in thedistrict.The trend of the mounts and cliffs was usually parallel to the first set of fractures.The rock columns and peaks were resulted from the cubic blocks cut by the two sets of frac-tures.Erosion and Karst erosion along the fractures created the landform of crevices and nar-row channels.The doline-like landform was developed at the intersections of the two sets offractures.The formation of the bedded caves in the district was considered relative to the diage-netic joints.The geological processes that formed the landform are also discussed in this paper.A-mong the processes,erosion,Karst erosion and éboulement were the most important.The firsttwo processes played important roles in the youth stage of Danxia landform,and after theappearance of cliffs,éboulement became dominant.A model for the development of Danxia la(?)dform is presented in this paper.The authorsconsider that the Jinjiling district is now in the mature stage of Danxia landform.