Tardiglacial and Holocene deposits in the middle Loire River, the Val d'Avaray case study (Loir-et-Cher, France)

Incision and infilling of the flood plain of the Loire river, in the Val d' Avaray area, is polyphased during Tardiglacial and Holocene. Five main allu vial units are developed and result from successive meandering-like phases of erosion and sandy infilling. Clayey channel fillings sometimes associate d with pear have been identified within the sandy units. The first investig ated channel was active from Tardiglacial (11.4 ka BP, Allerod) to Boreal, the second one from 8.4 ka BP (Boreal) to 2.3 ka BP (Subatlantic) with an a verage sedimentation rate of 0.5 mm.yr(-1). A third one rv as active from 3 .2 ka BP (Subboreal) and during a great part of the Subatlantic; the averag e rate of sedimentation is evaluated at 1.3 mm.yr(-1). ((C) 1999 Academie d es sciences / Editions scientifiques et medicales Elsevier SAS.).