New mechanism of erosion: Gorges are eradicated by downstream sweep erosion

18 agosto 2014

Local surface uplift can block rivers, particularly in mountainous regions. The impounded water, however, always finds its way downstream, often cutting a narrow gorge into the rocks. Subsequent erosion of the rocks can lead to a complete eradication of this initial incision, until not a trace is left of the original breakthrough. In extreme cases the whole gorge disappears, leaving behind a broad valley with a flat floodplain. Previously, the assumption was that this transition from a narrow gorge to a wide valley was driven by gorge widening and the erosion of the walls of the gorges.