GEOLOGICAL FACTORS CONTROLLING THE FORMATION OF DANXIA LANDFORM, LONGHUSHAN,SOUTHEAST CHINA

Danxia landform (literally “red glow” or “rosy cloud”) is the name given in China to landscapes developed on continental, commonly red-colored, sedimentary formations characterized by steep cliffs with karst-like features (including caves). The study area of Longhushan, in Jiangxi province, boasts the archetypal danxia landform. The landform is developed in sedimentary breccias and sandstones of alluvial fan-type sequences that were deposited in Mesozoic rift basins. The basins are located on the NW side of a rhyolitic paleo-mountain range that was part of the Mesozoic “Andean-type” margin of southeast China. We have conducted remote sensing and field-based investigations to determine the major controls in the formation of this landform, focusing on the Luxi sub basin, which is an area with the highest concentration of danxia landforms. The result shows Regional main faults not only control the basin pattern from large scale but also influence the orientation of the Danxia Peaks. Most of the danxia mountains aligned NE-NNE from the lineaments extraction of the remotely sensed data. The main Xinjiang basin domain boundaries correspond to NE-NNE-trending master faults. Within the basin NNE and NW trending fracture domains dominate. Main stream valleys and subsidiary channels are clearly controlled by these fracture systems. Ground-based investigations reveal that many of the lineaments consist of conjugate normal faults. From the interpretation of the remotely sensed data, slot canyons with ~60 degree dips are also commonly developed by preferred erosion along normal faults.