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  • Core THU10-I : 18m long core An 18-m-long core was extracted in April 2010 from Lake "La Thuile" using a Uwitec platform and coring devices (Uwitec Usinger 90, Niederrreiter 63, Uwitec Gravity Pilote device) . Context of the study : Lake La Thuile, in the Northern French Prealps (874 m a.s.l.), provides an 18-m long sedimentary sequence spanning the entire Lateglacial/Holocene period. The high-resolution multi-proxy (sedimentological, palynological, and geochemical) analysis of the uppermost 6.2 m reveals the Holocene dynamics of erosion in the catchment in response to landscape modifications. The mountain belt is at relevant altitude to study past human activities, and the watershed is sufficiently disconnected from large valleys to capture a local sedimentary signal. From 12,000 to 10,000 cal. BP (10–8 kyr cal. BC), the onset of hardwood species triggered a drop in erosion following the Lateglacial/Holocene transition. From 10,000 to 4500 cal. BP (8–2.5 kyr cal. BC), the forest became denser and favored slope stabilization, while erosion processes were very weak. A first erosive phase was initiated at ca. 4500 cal. BP without evidence of human presence in the catchment. Then, the forest declined at approximately 3000 cal. BP, suggesting the first human influence on the landscape. Two other erosive phases are related to anthropic activities: approximately 2500 cal. BP (550 cal. BC) during the Roman period and after 1600 cal. BP (350 cal. AD) with a substantial accentuation in the Middle Ages. In contrast, the lower erosion produced during the ‘Little Ice Age’, when climate deteriorations are generally considered to result in an increased erosion signal in this region, suggests that anthropic activities dominated the erosive processes and completely masked the natural effects of climate on erosion in the late Holocene. Keywords : climate, Holocene, human activities, montane lake, terrigenous inputs, vegetation

  • Accessibilité des parcelle cadastrales du Pays de Brest depuis la mairie de Landerneau en 1952 pour une durée de trajet maximum de 30 minutes en voiture

  • Accessibilité des parcelle cadastrales du Pays de Brest depuis la mairie du Conquet en 1952 pour une durée de trajet maximum de 30 minutes en voiture

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    The objective of the national portal is to group in a single place metadatas associated with the marine, continental sedimentary cores stored and studied in the French laboratories. Cores contained in this portal are stemming from inventories of the numerous partners laboratories of the CNRS, IFREMER, MNHN, IRD, INRA. L'objectif du portail national est de regrouper en un seul lieu les métadonnées associées aux carottes sédimentaires marines, continentales et glaciaires stockées et étudiées dans les laboratoires Français. Les carottes contenues dans ce portail sont issues des inventaires des nombreux laboratoires partenaires du CNRS, IFREMER, MNHN, IRD, INRA. L’alimentation de la base est ouverte aux unités de recherche qui le souhaitent. Cette initiative a bénéficié de différents soutiens depuis 2014 : du C2FN pour son initiation dans le cadre de l'Equipex CLIMCOR (http://climcor-equipex.dt.insu.cnrs.fr/), de la DT INSU, l'OASU pour leurs soutiens techniques. Cette initiative a ete piloté par les "core repository" EPOC et EDYTEM pour la communauté Marine et continentale. Ce projet a benefcié également du rapprochement avec IFREMER et d’un effort spécifique mené dans le cadre d'actions autour des « archives sédimentaires » du réseau des Zones Ateliers du CNRS (http://www.za-inee.org/) du LTER France (Projet ROZA).

  • Accessibilité en voitures écoles du Pays de Brest en 1952, projetée sur les Parcelles du PCI

  • Core THU10-I-01a1 is the first run/section (0-127cm) of the THU10-I sequences Localisation : Lake La Thuile, in the Northern French Prealps (874 m a.s.l.), provides an 18-m long sedimentary sequence spanning the entire Lateglacial/Holocene period. The high-resolution multi-proxy (sedimentological, palynological, and geochemical) analysis of the uppermost 6.2 m reveals the Holocene dynamics of erosion in the catchment in response to landscape modifications. The mountain belt is at relevant altitude to study past human activities, and the watershed is sufficiently disconnected from large valleys to capture a local sedimentary signal. From 12,000 to 10,000 cal. BP (10–8 kyr cal. BC), the onset of hardwood species triggered a drop in erosion following the Lateglacial/Holocene transition. From 10,000 to 4500 cal. BP (8–2.5 kyr cal. BC), the forest became denser and favored slope stabilization, while erosion processes were very weak. A first erosive phase was initiated at ca. 4500 cal. BP without evidence of human presence in the catchment. Then, the forest declined at approximately 3000 cal. BP, suggesting the first human influence on the landscape. Two other erosive phases are related to anthropic activities: approximately 2500 cal. BP (550 cal. BC) during the Roman period and after 1600 cal. BP (350 cal. AD) with a substantial accentuation in the Middle Ages. In contrast, the lower erosion produced during the ‘Little Ice Age’, when climate deteriorations are generally considered to result in an increased erosion signal in this region, suggests that anthropic activities dominated the erosive processes and completely masked the natural effects of climate on erosion in the late Holocene. Keywords : climate, Holocene, human activities, montane lake, terrigenous inputs, vegetation Keywords (analyticals) : XRF, DRY-MATTER, LOI, GRAIN SIZE RADIOCARBON, SHORT LIVED RADIONUCLIDES, PHOTOGRAPHY

  • Accessibilité piétonne des écoles du Pays de Brest en 1952, projetée sur les Parcelles du PCI

  • Accessibilité des parcelle cadastrales du Pays de Brest depuis la mairie de Brest en 1952 pour une durée de trajet maximum de 30 minutes en voiture.

  • Accessibilité des parcelle cadastrales du Pays de Brest depuis la mairie de Lesneven en 1952 pour une durée de trajet maximum de 30 minutes en voiture