The Role of Lithology: Parent Material Controls on Badland Development

Abstract Badlands can develop on bedrock and/or weathered material, the characteristics of which play a key role on hillslope processes in a range of climate conditions. Therefore, fundamental attention should be given to badland materials, the main features of which are grain size, clay mineralogy and physico-chemical characteristics. The typical weathering profile consists of crust, subsurface and unweathered material, but depending on climatic, lithological, topographic and hydrological factors, the properties and appearance of both surface and subsurface materials change over time. Through time, regolith formed on erodible and dispersive bedrock materials tends to stabilize, again as a function of slope and climate conditions because prolonged precipitation can cause decrease in surface strength and runoff and reduce the dispersivity of the surface. Vegetation also has distinct role in stabilizing the clayey sediments due to lowering the dispersivity in the upper horizon of the badland material, even though such stabilization is often not permanent and erosion processes can sometimes reoccur. Finally, all the above cited factors and properties of badland materials play a complex and key role in the development of different geomorphic processes and related landforms.