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Article dans une revue
ESR dating of fluvial quartz : new chronological data for the intermediate sector of the Creuse river valley (Indre, Centre region, France)
Abstract : Since the 1990's, systematic dating of the alluvial deposits by the Electron Spin Resonance (ESR) method applied to optically bleached quartz had been undertaken in the Middle Creuse Valley (Indre department, France). Because of different substrata, the studied area had been divided into three sectors: the Massif Central, Intermediate and Parisian Basin sectors. The first data indicated that the stepped and embedded terraces of the fluvial system were deposited between 1.7 Ma and 130 ka, but it was difficult to correlate the results obtained in the three sectors, particularly for the Intermediate sector, where recent tectonics seems to have had a strong impact on the fluvial system geometry. In this sector which corresponds to the fault trough of Argenton-sur-Creuse, ten stepped or embedded fluvial formations (named I to X) had been described but only the lower sheets (I to VII) had been sampled and dated in previous works. Since 2000, systematic fieldworks have allowed the study of the higher formations (VIII, IX and X) and new samples were also taken in the middle-system sheets (V to VII). The results presented in this paper supplement the previous data, notably with the dating of some of the oldest alluvial sheets deposited in the Argenton-sur-Creuse fault trough. A better correlation with the upstream Massif Central sector is now possible and confirms the onset of the river incision during the Early Pleistocene and the evolution of the Creuse fluvial system all along the Middle Pleistocene.
https://hal-brgm.archives-ouvertes.fr/hal-01851537
Contributeur : Myriam Chergui Connectez-vous pour contacter le contributeur
Soumis le : lundi 30 juillet 2018 - 13:28:07
Dernière modification le : mardi 16 novembre 2021 - 05:17:18
Contributeur : Myriam Chergui Connectez-vous pour contacter le contributeur
Soumis le : lundi 30 juillet 2018 - 13:28:07
Dernière modification le : mardi 16 novembre 2021 - 05:17:18