Excursions to C-4 vegetation recorded in the Upper Pleistocene loess of Surduk (Northern Serbia): an organic isotope geochemistry study

• Published in: Climate of the Past
• Main Authors: Hatté, Christine, Gauthier, C., Rousseau, D. -D., Antoine, P., Fuchs, M., Lagroix, F., Markovic, S. B., Moine, O., Sima, A.
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Géochrononologie Traceurs Archéométrie (GEOTRAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Department of Geography, Justus-Liebig- University, Justus-Liebig-Universität Gießen = Justus Liebig University (JLU), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Univ Novi Sad, Chair Phys Geog, Novi Sad 21000, Serbia, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X), Institut Polytechnique de Paris (IP Paris)-Institut Polytechnique de Paris (IP Paris)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; North Atlantic
• Online Access: https://hal.science/hal-01092199; https://hal.science/hal-01092199/document; https://hal.science/hal-01092199/file/cp-9-1001-2013.pdf; https://doi.org/10.5194/cp-9-1001-2013

International audience Loess sequences have been intensively studied to characterize past glacial climates of the 40-50 north and south latitude zones. Combining different approaches of sedimentology, magnetism, geochemistry, geochronology and malacology allows the general pattern of the climate and environment of the last interglacial glacial cycle in Eurasia and America to be characterized. Previous studies performed in Europe have highlighted the predominance (if not the sole occurrence) of C-3 vegetation. The presence of C-3 plants suggests a regular distribution of precipitation along the year. Therefore, even if the mean annual precipitation remained very low during the most extensive glacial times, free water was available for more than 2 months per year. Contrarily, the delta C-13 record of Surduk (Serbia) clearly shows the occurrence and dominance of C-4 plants during at least 4 episodes of the last glacial times at 28.0-26.0 kyr cal BP, 31.4-30.0 kyr cal BP, 53.4 /14.5 kyr cal BP and 86.8-66.1 kyr. The C-4 plant development is interpreted as a specific atmospheric circulation pattern that induces short and dry summer conditions. As possible explanation, we propose that during "C-4 episodes", the Mediterranean Sea would have been under the combined influence of the following: (i) a strong meridional circulation unfavorable to water evaporation that reduced the Mediterranean precipitation on the Balkans; and (ii) a high positive North Atlantic Western Russian (NA/WR)-like atmospheric pattern that favored northerlies over westerlies and reduced Atlantic precipitation over the Balkans. This configuration would imply very dry summers that did not allow C-3 plants to grow, thus supporting C-4 development. The intra-"C-4 episode" periods would have occurred under less drastic oceanic and atmospheric patterns that made the influence of westerlies on the Balkans possible.