Etablishing the first continuous Holocene tephrostratigraphy on Kerguelen Archipelago, subantarctic Indian Oean
- 1Environment Dynamics and Territories of the Mountains (EDYTEM), Université Savoie Mont-Blanc, CNRS, 73000 Chambéry, France
- 2Laboratoire des Sciences du Climat et de l’Environnement (LSCE), CEA, CNRS, 91 Gif-sur-Yvette, France
- 3Laboratoire Magmas et Volcans, Université Jean Monnet, CNRS, 42023 Saint-Etienne France
- 4Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes, CNRS, Grenoble, France
- 5Department of Earth Science and Bjerknes Centre for Climate Research, University of Bergen, Allégaten 41, 5007 Bergen, Norway
- 6Institut Paul-Emile Victor (IPEV), 29280, Plouzané, France
- 7Renard Centre of Marine Geology, Department of Geology and Soil Sciences, Ghent University, Krijgslaan 281 S8, B-9000 Ghent, Belgium
- 8Institut Méditerranéen de Biodiversité et d’Ecologie marine et occidentale (IMBE), Aix-Marseille Université, CNRS, 13545 Aix en Provence, France
Here we present the first Holocene-long continuous chronology of volcanic eruptions on Kerguelen archipelago, where no evidence of Holocene volcanic activity has been published so far. Our chronicle is based upon sedimentological, chronological and geochemical data form two sediment cores, taken in two different depocenters of a large lake, Lake Armor, located ca. 70 km away from the archipelago’s potentially active volcanic area. This allowed us to confidently attribute the origin of pumice-rich or ash-rich layers to contemporaneous volcanic eruptions. Altogther eight main eruptions, as well as three secondary ones, were here documented and dated, among which the youngest occurred during the Middle Age, between 890 and 980 AD. The oldest eruption is also by far the strongest one and deposited more than 1.2m of up-to 3cm large pumices, 70 km away from the volcanic edifice. It occurred at the very beginnning of the Holocene (11 ka cal. BP), suggesting a climatic control after glacial retreat upon volcanic activity. Additionnal evidences from lake sediment and geological outcrops, both close to Lake Armor and in remote areas over Kerguelen mainland, open the future possibility of a better reconstruction of major eruptions deposit spreading and thus an assessment of their intensity. This established chronostratigraphy will be useful to synchronise paleoenvironment record at least at the scale of the archipelago as well as in surrounding marine areas where Holocene climate reconstructions are particularly sparse.
How to cite: Arnaud, F., Sabatier, P., Leloup, A., Servettaz, A., Moine, B., Develle, A.-L., Guédron, S., Perrot, V., Poulenard, J., Fanget, B., Malet, E., Støren, E., Reyss, J.-L., Le Viavan, N., Heirman, K., De Batist, M., Michel, E., de Beaulieu, J.-L., Vanderputten, N., and Bakke, J.: Etablishing the first continuous Holocene tephrostratigraphy on Kerguelen Archipelago, subantarctic Indian Oean, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5782, https://doi.org/10.5194/egusphere-egu2020-5782, 2020