Mining: Extraction of fossil fuels

Abstract

The establishment of opencast mines is a kind of direct excavational process. From a geomorphological aspect, after the removal of the overburden and during working the seams, erosion starts immediately, but is kept under control to secure exploitation during the time of extraction. In this case, the stabilisation of the side-walls and the drainage of spring water are problems to be solved. Vertical dislocations, called subsidence, are semi-anthropogenic processes. Major subsidence landforms develop after the termination of uniform mechanised extraction, when large subsurface hollows of several metres' height collapse. Large-scale surface alterations are observed between a few days and a few years following mine closure. Water saturation in the fractured zones of loose rock brings about specific morphological changes, even rises in surface elevation. As a by-product of coal mining, inert overlying sediments and the intermediate waste rock between coal layers are piled in the form of spoil heaps. These hills with a height of more than 100 m are hallmarks even after landscaping. The extraction of mineral oil and natural gas also result in modification of topography in the region affected. © 2010 Springer Science+Business Media B.V.