福建冠豸山丹霞地貌成因及旅游景观特色

Danxia Landform Genesis and Scenic Feature on Guanzai Mountain, Fujian Province

福建冠豸山自晚侏罗世以来经历了山间盆地形成和侏罗、白垩系巨厚砂砾岩堆积成岩阶段 ,新构造运动中使盆地隆升和节理发育。自第三纪以来主要经历了 4次较大幅度具掀斜性质的抬升过程。从 4级夷平面的相对高差可知 ,第一、二次抬升之间幅度差为 34～ 78.8m,第二、三次抬升之间的幅度差为 81～ 1 0 0 m,第三、四次为 38～ 46m。在抬升过程中 ,受内力挤压和四周围岩压力逐渐消失造成的卸荷作用影响 ,岩层出现众多深大裂隙和多组垂直节理 ,发育有石墙、石堡 (寨 )、陡崖壁、柱峰、石梁、隙谷、嶂谷、峰林、峡谷、巷谷、天生桥等的丹霞地貌 。

At present, the genesis mechanism and evolution processes of Danxia landforms are the foci of study on the field of geomorphology and tourism. Guanzai Mountain of Fujian Province is a National A level scenic district. Its landform belongs to Danxia landforms in the maturity stage. Since late Jurassic period, this area experienced the stages of intermontane basin formation and the thick sandy gravels (J 3c, K 2s and K 2ch)accumulation and diagenetic evolution. During the neotectonic movement, the area experienced stages of basin uplift and joint development. The four grade planation surfaces and the monoclinal mountain characteristics with strata dip of 110°SE and dip angle of 13°～25°in the area illustrate that the area has experienced four episodes of large scale tilting uplift processes since Tertiary period. According to the relative height differences of the four grade planation surfaces, we can infer that the difference of uplift amplitude is 34～78 8 m between the first and second uplift movement, 81~100 m between the second and third, and 38~46 m between the third and fourth. During the uplift processes, influenced by internal agent compression, gradual disappearance of wall rock pressure and stress release, the hard K 2ch rock body formed numerous deep fissures and vertical joints. Then, the surface water eroded and dissected the rock along the fissures and joints, so made the K 2ch rock body collapse and retreat incessantly. As a result, a lot of rock core and rock prisms were created from the rock body. Thus, the Danxia landscapes with peak cluster and gullies were formed. Since the landscapes consist of dike wall, castellated peak, steep cliff, columnar peak, rock ridge, crack valley, flat bottom valley with same width from top to bottom, peak forest, canyon, lane valley, natural bridge, roof like cave, penetrative cave, flat niche and so on, therefore, they are of very high value for tourism exploitation.