中国丹霞地貌研究进展

A Survey of the Danxia Landform Research in China

从本世纪３０年代陈国达提出“丹霞地形”的概念以来，中国学者经历了初创、成型和发展三个阶段的研究，作为地貌学一个新领域的丹霞地貌研究已日趋成熟。“红色陆相碎屑岩”作为丹霞地貌的物质基础和“陡崖坡”作为形态限定为大部分学者所接受。“顶平、身陡、麓缓”的坡面组合，是丹霞地貌的基本形态特征。目前所发现的红层均不早于中生代；大部分丹霞地貌发育在红色砾岩、砂砾岩、砂岩的地层组合上，而相对软弱的粉沙质和泥质岩多发育红层丘陵。丹霞地貌发育的构造基础表现在区域构造控制沉积盆地；盆地内部构造控制丹霞山块格局乃至山块形态；岩层产状对丹霞地貌形态的影响主要是对于山块顶面和构造坡面的控制；而地壳升降则控制地貌发育的进程。直接影响丹霞地貌发育的外动力主要有流水、风化、和重力等作用，其中流水是塑造丹霞地貌的主动力；流水侵蚀和风化提供了重力崩塌的条件，而丹霞陡崖坡则往往是崩塌面或经后期改造的崩塌面。在干旱区，风力侵蚀和盐风化对于丹霞地貌外表形态塑造具有不可忽视的作用；在湿润区，生物对风化作用有一定影响。丹霞地貌区往往是生态相对比较脆弱的地区，但却风景优美，文化景观丰富，大多具有较好的旅游开发价值。

Danxia landform belongs to red terrestrial elastic rock landform, which is characterized by its red cliffed scarp. The development of Danxia land form research in China experienced three history stages, i. e.; Prof. Guoda Chen raised initial establishment and taking shape and expanding since the concept 'Danxia landform' in 1939. As a new branch of geomorphology, Danxia land form research is now stepping its ripe stage. In 90' s, their search enters into an unprecedented grand occasion at the prompting of tourism exploit. Danxia landform is classified into rock land form system. That the red terrestrial elastic rock being its material base and that steep scarp being its type form are accepted by most of researcher in this field. The constitution of leveled-top and cliffed-scarp and gentle-fool is the type shape of Danxia landform. In different area, the provincial characteristics of Danxia landform are different from each other due to their geography environment differences. Danxia land form developed only when the Earth crust reached its specified development stage, e. g., all red beds found on the Earth are not earlier than Mesozoic era. Most of Danxia landforin formed on red conglomerate rock, sand-conglomerate rock and sandstone. Meanwhile, red bed hills formed on siltstone and mud stone due to their flexible texture. The regional tectonic pattern, which controlled the distribution of sedimentary basins, is the tectonic base of Danxia landform. Tectonic lines within the basin controlled the distribution pattern and even the shape pattern of Danxia landform mountains. Supper surface of a mountain and tectonic dome of Danxia landform were controlled by the rock occurrences. Crystal movement controlled the development of Danxia landform. Exogenetic forces influenced the Danxia landform development included alleviation and weathering and gravitation processes, among which the alleviation process is the main force formed the Danxia landform. Alluvial corrosion and weathering created favorable condition for the gravitational eboulement, Danxia landform cliffed scarp is often the eboulement surface or reformed one. Wind erosion and saline weathering are unponderable forces in forming Danxia landform in arid zone. Organism activity is advantageous to weathering in humid zone. Artificial Danxia land form landscape is the product of exploiting stone. Danxia landform often distributed in weak ecology system areas; however, its tourism development value is often high due to its beautiful landscape and plentiful cultural scenery. The Danxia landforin research is aim at its development principles, taxonomy, landscape quality evaluation and graduation, natural mountains and river culture and human culture scenery, nature resource protection and utilization, and etc. All of which are beneficial to regional economic construction. In recently years, symposium of Danxia land form landscape resource and its tourism development are very active, which make a great contribution to regional tourism development.