The morphodynamic evolution of the dale and valley bottoms in the Maine and the Cher basins (south-west Paris basin) since the Lateglacial period

A series of cross sections and drillings in the infilling deposits of the d ales and valleys of the Maine and the Cher basins, allows us to assess the morphodynamic evolution which has taken place since the Lateglacial period, and to insist on the longitudinal changes. The Lateglacial incision appear s to have been general but very unequal in an upstream-downstream direction , for every river, whatever its length. The effects of downstream erosion d id nor go as far as those of the upstream erosion, so that the Weichselian alluvial sheet of periglacial origin lies buried under the Holocene deposit s in the middle parts of the rivers, whereas it lies above in the upstream and downstream sections. The Holocene infilling deposit, coarse in its lowe r part, especially on the outer limits north of the Massif Central. is cons tituted mostly of silts resulting from an overflow which did not occur befo re the Subboreal period; the whole process is both climatic and anthropic.