【作者】 刘江龙；

【导师】 吴湘滨； 申志军；

【作者基本信息】 中南大学 ， 国土资源信息工程， 2009， 博士

【摘要】 丹霞地貌是在中国命名并发展起来的一种特殊的红层地貌,已经走过近80年的研究历程。但绝大部分是从地貌景观资源开发和旅游市场开拓角度出发,而从地质地貌学的角度对其形成机理、发育过程及其地学效应的研究一直是个薄弱环节。通过对丹霞地貌区广泛的调查和分析,选取中国东南部湿润区丹霞地貌作为研究对象,以现代地貌学发展的最新理论为指导,采取野外考察和文献研读相结合、区域联系和对比分析相结合、岩石野外采样和室内分析鉴定相结合、单因子分析和系统关联性分析相结合,系统研究和专题研究相结合,对东南部丹霞地貌形成机理及其地学效应进行研究。首次系统地对中国东南部丹霞地貌发育因素的构造背景、沉积环境、地层岩性、构造运动、外动力机制、演化过程与阶段进行研究,开创性的对丹霞地貌的地球科学效应、地学美学效应、地学生态效应和地学人文效应进行了探讨,尝试性的对崀山丹霞地貌的景观特征及其世界遗产价值进行挖掘,主要取得如下成果:（1）形成于中生代炎热干燥气候条件下的红层盆地,燕山运动促使东部断陷盆地发生大规模岩浆活动,形成的钙碱性火山岩及双峰式火山岩系,具有弧后拉张性盆地特点,反映了一种特殊的红层盆地发育模式—弧后拉张性盆地。而深处于内陆的红盆缺乏岩浆活动。（2）东南部各红层盆地均以较稀疏的NNE向和近NS向断层构成主要构造线,同时发育了近EW向和NE、NWW向断层。大的构造线控制了山块总体的排列方向,次级构造则控制山块的走向、密度和平面形态,不同方向的节理使地貌更富于多样化。由于新构造运动的差异性使较早抬升的区域保持长期稳定,有利于丹霞地貌从幼年期到老年期演化;间歇性抬升区域则发育多层性丹霞地貌。（3）流水侵蚀作用和雨水冲刷作用是雕塑丹霞地貌主导外动力,其侵蚀作用方式不同、对不同岩性的侵蚀强度各异;软硬岩层之间的差异风化形成丹霞地貌陡崖坡上独特的微地貌景观;重力崩塌作用参与丹霞地貌的塑造,加速了新一轮流水侵蚀和风化作用的进行。由此将丹霞地貌分为流水侵蚀型、雨水侵蚀型、崩塌残余型、崩塌堆积型、冲刷溶蚀型等五种成因类型。东南部丹霞地貌包含了完整的演化旋回,展现了从青年期→壮年期→老年期三大地貌阶段的九个典型地貌过程的自然演化序列。（4）东南部丹霞地貌集地质多样性、地貌多样性、生物多样性、生态独特性及景观珍奇性于一体,记录了一亿多年以来欧亚板块华南区域陆壳断陷盆地的地质历史和地球中生代以来古地理环境及古气候变迁历史,反映了地球中生代晚期—新生代阶段的地球陆地表层系统的全球性变化和重大事件,孕育了世界上已知丹霞地貌中分布最密集、造型最精美的地貌形态,包含了多种典型而突出的珍稀濒危生物物种及栖息地,历史人文遗迹以极其独特的方式融合在自然美之中。这些具有全球意义的自然现象、自然演化过程和杰出的天然美景,集中展示了丹霞地貌的地球科学、地学生态、地学美学和地学人文四大效应。（5）中国白垩纪红层全为陆相,而国外红层既有陆相也有少量滨海相;中国白垩纪红层被塑造成丹霞地貌的过程经过了干热气候向湿热气候的转换,而国外丹霞地貌的发育过程缺少这一环节;中国东南部大陆处于三大板块交汇处,地壳抬升强烈,青藏高原的上升对中国大气环流及现代地势分布影响剧烈,中国丹霞地貌是在这特定的地质时期内气候环境发生转变的条件下形成了一种标志性的岩石地貌,而国外同期红层地貌则不具有这种标志性。（6）通过野外调查和岩矿鉴定,崀山红层总厚度200～2320m,砂砾岩类型多样,岩石中SiO₂,Al₂O₃和CaO的含量较高、K₂O和Na₂O含量较低。说明崀山红层的抗风化能力强、喀斯特现象突出。崀山地区经历了多次间歇性地壳抬升,地貌发育过程清晰,形态结构完整,以圆顶密集式壮年期丹霞峰丛峰林为最大特色;巷谷、线谷和天生桥规模宏大;独特的丹霞喀斯特微地貌和丹霞与喀斯特复合地貌;造型地貌丰富多彩。更多还原

【Abstract】 Danxia landform is a specific petrographic geomorphology, named from Danxiashan, in Guangdong Province, in China. Danxia geology and geomorphology have been studied for about 80 years in China. Over the past years most studies focusd on the research of Danxia landscape resources and tourism market development, but few attached to the geological formation mechanism, morphology development process, or its geoscientific values.Based on the extensive investigation and analysis, Danxia landform in southeast China is selected as the research object, the latest theory in modern geomorphology is applied. Through the field survey and literature study, connecting contrast analysis of different region, combining the single factor analysis and correlation analysis, sampling rockmine outdoor and characterizing rock indoor, the Southeastern Danxia landform and geo-scientific effects were comprehensively researched.The first systemic research on Southeast China danxia landform development factors including tectonic background, sedimentary environment, lithology, tectonic movement, the exogenic action mechanism and the evolution process has been finished. The geo-scientific effects of danxia landform have been groundbreakinglly analyzed. The landscape characteristics and its world heritage value of Danxia landform in Langshan have been made known. Main conclusions as following:The red bed basins were formed in hot and dry climates environment in the Mesozoic. Yanshan movement in eastern prompted to massive magmatic activity in fault red bed basins, then calcium alkaline volcanic rocks and bi-model volcanic series were formed. The phenomenon gives a explain of a kind of special red bed basin development mode. But there were lack of magmatic activity in inland red bed basin. Red diluvial clastic rocks are composed of the main material base of danxia landform.From the study of the various units of the geological structure, the Southeast China region has mostly a series of sparse NNE and near NS faults, leading to the arrangement of hill blocks oriented NNE or nearly NS. On the other hand, most parts of the basins in the Southeast China area also developed some near EW, NE, and NWW faults. These large tectonic lineaments controlled the general arrangement of hill blocks, and the small structures controlled the trend, density and plane pattern of hill blocks.Danxia landforms were in a differential and intermittent uplift zone during the Neotectonics Movement. Where the region was uplifted in an early stage followed by a long-term stable state this allowed for successive and gradual evolution of Danxia landsapes from infancy to old stage. However, intermittent uplift causes the development of multi-layered Danxia landscapes.Fluvial erosion and rain flushing action is the dominant exogenic action sculpturing danxia landform, the lithology differences between soft rocks and hard rocks lead to different role of erosion, then create unique landscape on Danxia cliff. Gravitational collapse plays a role of the accelerator in shaping the danxia landform acting on another round of water erosion and weathering. The figure of Southeast danxia landforms will be divided into five types such as fluvial erosion type, rain flushing type, vestigital type after collapse, talus ruoble type and dissolution type. Southeast danxia landforms include landscapes at different stages in their geomorphic evolution, with different landform types and different combinations of landscape features. All stages in landscape evolution are present from youth through maturity to old age.Collectively, Southeast Danxia landforms display geological diversity, landform diversity, biological diversity, ecology uniqueness and landscape rareness. Because of the unique geological structural background and natural geographic location, Danxia landform displays the earth’s history since the late Mesozoic, showing geological and landform process of the continental crust, and is a model site for the study of the evolution of earth’s continental fault basins and on-going geological process. It also is an ideal place to study the global climate change over long geological periods. Evidence of important geological events are included such as aeolian accumulations, dinosaur life and extinction, basin uplift, continental volcanism and crustal deformation -all occurring in a region of hot-arid climate. The evolution of Danxia landform reflects global changes and major events in the earth’s land surface system since the late Mesozoic-Cenozoic, which may be significant for research on current global changes. Southeast danxia landform displays the development of landscapes and landforms with a distinct morphology, shape, colour and appearance. And gives the presence of various typical and outstanding, rare and endangered biological species and habitats. All these give collectively expression to geo-scientific vaule, natural beauty and aesthetic importance, Ecological values and harmonious coexistence between humanity and nature.Chinese cretaceous red beds was land facies, but the most foreign’s was not only land facies, but also a few of littoral facies. The Chinese Cretaceous red beds was fashioned to Danxia landform to after the conversion from the dry heat climate to the hot and damp, however, when overseas red beds landform developed, it lacked this condition of climate transformation. China’s mainland Mesozoic, because of the doubly extrusions between the Indian Plate and the Pacific Ocean Plate, the crust lifted intensely, especially the uplift of Qinghai-Tibet Plain, was an important milestone for the Chinese modern atmospheric circulation and the modern topography distribution. In such a specific geological period, the Chinese Danxia landform was formed to be one kind of special vicissitude symbolic rock landform of ecological environment. But the overseas same time red beds landform did not have this kind of symbol.In Langshan Mountain the thickness of Langshan red beds changes from 200 to 2320m. There are multitudinal kinds of rocks charactered with good anti-airstake ability and obvious karst phenomenon. Due to high content of SiO₂ and Al₂O₃ and low content of CaO, K₂O and Na₂O, Langshan has experienced intermittent crustal uplift. The landscape of Langshan features dome-shaped landforms, with dense peak clusters and peak forests. There are linear valleys, large-scale natural bridges, and unusual karst-like features. The landscape here also has a rare degree of natural beauty. It is representative of a landscape in the mature stage of development, and is also an excellent example of a classic Danxia landscape.更多还原