TY - JOUR
T1 - Stratigraphy and chronology of Pleistocene coastal deposits in northern Aquitaine, France
T2 - A reinvestigation
AU - Bosq, Mathieu
AU - Bertran, Pascal
AU - Beauval, Cédric
AU - Kreutzer, Sebastian
AU - Duval, Mathieu
AU - Bartz, Melanie
AU - Mercier, Norbert
AU - Sitzia, Luca
AU - Stéphan, Pierre
N1 - Funding Information:
Nationale de la Recherche under the Programme Investissement d’Avenir (reference ANR-10-IDEX-03-02). We thank F. Verdin and F. Eynaud, in charge of the project, for giving us the opportunity to study the Pleistocene formations of the Médoc region, and the other participants, Frédéric Bertrand, Gilles Arnaud-Fassetta, Anne Colin, Antoine Kremer, Clément Lambert, Serge Suanez, Clément Coutelier, Stéphane Costa and Nathalie Prévôt. We also thank J.P. Tastet, who introduced us to the site during a previous ield campaign, and A. Queffelec for carrying out grain size analyses. S. Kreutzer received inancial support by the LaScArBx. LaScArBx is a research programme supported by the ANR (ANR-10-LABX-52). The ESR dating analyses have been funded by the Australian Research Council Future Fellowship grant FT150100215. D. Bridgland and an anonymous reviewer are acknowledged for their remarks, which contributed to improve the original manuscript.
Publisher Copyright:
© Tous droits réservés
PY - 2019/4/1
Y1 - 2019/4/1
N2 - Pleistocene deposits exposed along the coast of the Médoc area, south-west France, represent valuable palaeoenvironmental archives that have been the subject of extensive work in the past few decades. To further understand the palaeoenvironmental history and sedimentary dynamics of these deposits, a detailed lithostratigraphic study was performed on a series of new sections. Additionally, new chronological data were obtained from the combination of luminescence (OSL, IR-RF) and electron spin resonance (ESR) dating of quartz and feldspar grains (Kreutzer et al., 2018). The investigated sections comprise estuarine, lacustrine and peaty deposits (Négade Formation, Argiles du Gurp Formation), aeolian sands (Sables du Gurp Formation) and colluvial units (Grès de l'Amélie Formation). The Argiles du Gurp Formation, in which many remains of Palaeoloxodon antiquus were found, support the hypothesis of a progressive replacement of a tide-inluenced marsh by a peaty fresh-water pond during the Holsteinian Interglacial (MIS 11). IR-RF dating of green estuarine clays at L’Amélie, in the northernmost part of the investigated area, strongly suggests that they do not belong to the Argile du Gurp Formation, but were deposited during the MIS 9 sea level highstand. The estuarine deposits are overlain by sandsheets (Sables du Gurp Formation) dated to MIS 10 and MIS 8 at Pointe de la Négade in the southern part of the study area, and to MIS 8 at L’Amélie. Syngenetic frost cracks testify to a periglacial depositional environment. Regional studies show that the Sables du Gurp Formation is a local equivalent of the Sables des Landes Formation, and corresponds to the oldest aeolian phase recorded in south-west France so far. Colluvial material (Grès de l'Amélie Formation) dated to the Weichselian pleni-glacial (MIS 2) ill small palaeo-valleys incised in the Sables du Gurp Formation. Holocene coastal dunes cover the whole sequence.
AB - Pleistocene deposits exposed along the coast of the Médoc area, south-west France, represent valuable palaeoenvironmental archives that have been the subject of extensive work in the past few decades. To further understand the palaeoenvironmental history and sedimentary dynamics of these deposits, a detailed lithostratigraphic study was performed on a series of new sections. Additionally, new chronological data were obtained from the combination of luminescence (OSL, IR-RF) and electron spin resonance (ESR) dating of quartz and feldspar grains (Kreutzer et al., 2018). The investigated sections comprise estuarine, lacustrine and peaty deposits (Négade Formation, Argiles du Gurp Formation), aeolian sands (Sables du Gurp Formation) and colluvial units (Grès de l'Amélie Formation). The Argiles du Gurp Formation, in which many remains of Palaeoloxodon antiquus were found, support the hypothesis of a progressive replacement of a tide-inluenced marsh by a peaty fresh-water pond during the Holsteinian Interglacial (MIS 11). IR-RF dating of green estuarine clays at L’Amélie, in the northernmost part of the investigated area, strongly suggests that they do not belong to the Argile du Gurp Formation, but were deposited during the MIS 9 sea level highstand. The estuarine deposits are overlain by sandsheets (Sables du Gurp Formation) dated to MIS 10 and MIS 8 at Pointe de la Négade in the southern part of the study area, and to MIS 8 at L’Amélie. Syngenetic frost cracks testify to a periglacial depositional environment. Regional studies show that the Sables du Gurp Formation is a local equivalent of the Sables des Landes Formation, and corresponds to the oldest aeolian phase recorded in south-west France so far. Colluvial material (Grès de l'Amélie Formation) dated to the Weichselian pleni-glacial (MIS 2) ill small palaeo-valleys incised in the Sables du Gurp Formation. Holocene coastal dunes cover the whole sequence.
KW - Coversand
KW - Argiles du Gurp
KW - Palaeoloxodon antiquus
KW - Aquitaine basin
KW - Middle Pleistocene
KW - OSL
KW - IR-RF
KW - ESR
UR - http://www.scopus.com/inward/record.url?scp=85067648857&partnerID=8YFLogxK
U2 - 10.4000/quaternaire.11112
DO - 10.4000/quaternaire.11112
M3 - Article
SN - 1965-0795
VL - 30
SP - 275
EP - 303
JO - Quaternaire
JF - Quaternaire
IS - 1
ER -