Tl dating definition
Premiers éléments de datation des industries du Pléistocène moyen (Acheuléen - Paléolithique moyen ancien) de la région pyrénéo-garonnaise : une approche géochronologique pluri-méthodes (TL, OSL et TT-OSL) des sites de Duclos et Romentères The recent development work of the A65 highway has given the opportunity to broaden the corpus of Lower and Middle Palaeolithic open-air sites known in the southern Aquitaine basin.
The sites of Duclos (Auriac, Pyrénées-Orientales) and Romentères (Le Vignau, Landes), discovered in this context, have yielded an abundant lithic record which has been attributed to the Acheulean of Iberian type for the earlier and, essentially, to the Early Middle Palaeolithic for the latter.
They each show distinct characteristics, in their colour as well as by the clayey illuviation.SThe redder their colour is, the older they are (IIBTg: 7.5 YR, IIIBTg: 5YR, IVBTg: 2.5YR) probably because of progressive transformation of the oxides through time resulting in the formation of less hydrated minerals (Duchaufour 1983; Cremaschi 1987).The chronological hypothesis proposed by the lithostratigraphic study suggests an Eemian age (last interglacial, MIS 5) for horizon IIBTg, while horizon IIIBTg would correspond to the previous interglacial (MIS 7).Romentères: the ploughed soil is not visible because it was previously stripped.The site of Duclos (Colonge dir., pending) has yielded a characteristic lithic series of the Pyrenees-Garonne Acheulean, very close to the Acheulean of Iberian type (Colonge and Texier 2005; Mourre and Colonge 2007.) In particular this industry features a specific production of large blanks, a distinctive bifacial fashioning (mostly nucleiform) and the fashioning of cleavers and polyhedrons. The most important collection, with over 4,500 objects, is densely spread in the upper part of the “middle silts” (IIBTg) and comes partly (about 15 %) from the “upper silts”.