RELATIVE UPLIFT MEASURED USING RIVER INCISIONS - THE CASE OF THE ARMORICAN BASEMENT (FRANCE)

River incision is a potential tool to quantify uplift of continental a reas. However, river incision measurements using valley depths are dif ficult because of their variability at the catchment scale. We present a new method to quantify incision, by measuring valley depth accordin g to their width, taking into account all the valleys in each catchmen t. Systematic differences in valley depths between catchments are quan tified, related to relative uplift between them. An application on Bri ttany makes it possible to quantify a relative uplift of 30 m between two catchments during Quaternary times. ((C) Academie des sciences / E lsevier, Paris.).