 |
university of Provence - Aix-Marseille I |  |
|
university of Provence - Aix-Marseille I | |
| HAL: insu-00576530, version 1 |
| DOI: 10.1177/0959683610391320 |
| Detailed view |  Export this paper |
 |
| The Holocene 21, 4 (2011) 651-665 |
|
|
|
|
| Changes in erosion patterns during the Holocene in a currently treeless subalpine catchment inferred from lake sediment geochemistry (Lake Anterne, 2063 m a.s.l., NW French Alps): The role of climate and human activities |
|
|
| Charline Giguet-Covex 1Fabien Arnaud 1 |
|
|
| (2011) |
|
|
|
| A high-resolution sedimentological and geochemical study was performed on a 20 m long core from the alpine Lake Anterne (2063 m a.s.l., NW French Alps) spanning the last 10 ka. Sedimentation is mainly of minerogenic origin. The organic matter quantity (TOC%) as well as its quality (hydrogen (HI) and oxygen (OI) indices) both indicate the progressive onset and subsequent stabilization of vegetation cover in the catchment from 9950 to 5550 cal. BP. During this phase, the pedogenic process of carbonate dissolution is marked by a decrease in the calcium content in the sediment record. Between 7850 and 5550 cal. BP, very low manganese concentrations suggest anoxic conditions in the bottom-water of Lake Anterne. These are caused by a relatively high organic matter (terrestrial and lacustrine) content, a low flood frequency and longer summer stratification triggered by warmer conditions. From 5550 cal. BP, a decrease in TOC, stabilization of HI and higher sedimentation rates together reflect increased erosion rates of leptosols and developed soils, probably due to a colder and wetter climate. Then, three periods of important soil destabilization are marked by an increased frequency and thickness of flood deposits during the Bronze Age and by increases in topsoil erosion relative to leptosols (HI increases) during the late Iron Age/Roman period and the Medieval periods. These periods are also characterized by higher sedimentation rates. According to palynological data, human impact (deforestation and/or pasturing activity) probably triggered these periods of increased soil erosion. |
|
|
|
|
|
|
|
|
|
|
|
| 1: | Environnements, Dynamiques et Territoires de la Montagne (EDYTEM) |
|
|
|
CNRS : UMR5204 – Université de Savoie |
|
|
| 2: | Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL) |
|
|
|
Institut national de la recherche agronomique (INRA) : UMR0042 – Université de Savoie |
|
|
| 3: | Institut des Sciences de la Terre d'Orléans (ISTO) |
|
|
|
Université d'Orléans – CNRS : UMR6113 – Université François Rabelais - Tours – INSU |
|
|
| 4: | Centre d'Études Préhistoire, Antiquité, Moyen-Age (CEPAM) |
|
|
|
CNRS : UMR6130 – Université Nice Sophia Antipolis [UNS] |
|
|
| 5: | Centre Eau, Terre et Environnement |
|
|
|
INRS – Institut National de la Rercherche Scientifique (INRS) |
|
|
| 6: | GEOTOP |
|
|
|
Geotop |
|
|
| 7: | Centre européen de recherche et d'enseignement de géosciences de l'environnement (CEREGE) |
|
|
|
CNRS : UMR6635 – Institut de recherche pour le développement [IRD] – INSU – Université de Provence - Aix-Marseille I – Université Paul Cézanne - Aix-Marseille III |
|
|
| 8: | Lower Saxony Institute for Historical Coastal Research |
|
|
|
Lower Saxony Institute for Historical Coastal Research |
|
|
|
|
|
|
|
|
|
| subject | : | Sciences of the Universe/Earth Sciences/Climatology Environmental Sciences/Global Changes |
| insu-00576530, version 1 | |
| http://hal-insu.archives-ouvertes.fr/insu-00576530 | |
| oai:hal-insu.archives-ouvertes.fr:insu-00576530 | |
| From: Nathalie Pothier | |
| Submitted on: Monday, 14 March 2011 15:49:05 | |
| Updated on: Monday, 23 January 2012 17:24:26 | |
