摘要

This study of Durance River terrace morphologies in the lower 200 km of the valley shows that terrace ages, elevations and heights above the river generally all increase upstream. It is based on extensive fieldwork checked against geological maps and memoirs. Subdivision of the valley, based on gorges and former tectonic blockages, is relevant because there are no Durance terraces downstream of Mallemort and there are considerable differences between each reach. For most of the Pleistocene, the river was diverted through the Crau Plains to the sea. Below the Mirabeau gorge, there are a few narrow low and middle terraces. The best terrace development is between Mirabeau and the Sisteron defile. Upstream of that barrier there is glacial dominance. Changes in terrace continuity are illustrated by means of height-range diagrams and their rates of dissection have been quantified approximately, based on cosmic ray exposure age modelling. Climate forcing cannot explain all the changes found. The influence of tectonic activity was found to increase in an upstream direction and also with age on the southwestern flanks of the Alps.

  • 出版日期2012-9