Lithostratigraphy of Meurthe and Sarre terraces in the vicinity of the Vosges and Hunsruck (France, Germany): fluvial response to Pleistocene climate change

作者：Occhietti Serge^*; Cordier Stephane; Harmand Dominique; Kulinicz Emmanuelle

来源：Geomorphologie-Relief Processus Environnement, 2012, (4): 441-458.

• fluvial terraces
• Pleistocene
• lithostratigraphy
• fluvial incision
• Meurthe River
• Sarre River

The paper focuses on the fluvial sediments of the terraces Me4 and Me1 of the Meurthe River and Sa4 of the Sarre River, which have been investigated downstream from the Vosges Massif and in the southern Hunsruck, respectively. A lithostratigraphic study led to the recognition of four lithofacies. The sediments associated with pleniglacial periods are mainly of proximal origin, Permo-Triassic stratas for the Meurthe River, Devonian basement for the Sarre River, and correspond to valley floor infills that have been formed under periglacial conditions. Their identification in the sections enables their use as stratigraphic markers. In the two valleys under study, basal units associated with the warm-to-cold transition have been deposited under continental climate and provide evidence for the influence of seasonal ice rafting. In the Meurthe valley, units related to late glacial or late stadial periods include a higher proportion of sediments from the upper catchment. They are preserved above the previous deposits of the older Meurthe terraces (Me4, Me3 and Me2), but also at the base of terrace Me1 and the present floodplain Me0. Finally the fine-grained interglacial or interstadial units are preserved at the top of the fluvial series. This lithostratigraphic approach demonstrates that incision predating the deposition of terrace sediments related to Me4, Me3 and Me2 took place at the beginning of cold periods. In contrast, the Me2-Me1 and Me1-Me0 incisions occurred during late stadial or late glacial episods. The terrace Me1 and the present floodplain Me0 could hence be eroded during the next climate cycle, as was the case for the older terraces. The latter are actually residual, especially in the Meurthe valley which is characterised by a progressive narrowing since the formation of Me4. The results are consistent with the available chronological framework and provide information about the formation of the fluvial terraces in the vicinity of old massifs, opening the way to comparison with the downstream areas.

• 出版日期2012-12