A major hydrobiological change in Dasht-e Arjan Wetland (southwestern Iran) during the late glacial – early Holocene transition revealed by subfossil chironomids

• Published in: Canadian Journal of Earth Sciences
• Main Authors: Aubert, Cyril, Djamali, Morteza, Jones, Matthew, Lahijani, Hamid, Marriner, Nick, Naderi-Beni, Abdolmajid, Sharifi, Arash, Ponel, Philippe, Gandouin, Emmanuel
• Other Authors: Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement IRD : UMR237-Centre National de la Recherche Scientifique (CNRS), University of Nottingham, UK (UON), Iranian National Institute for Oceanography and Atmospheric Sciences (INIOAS), Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté COMUE (UBFC)-Université Bourgogne Franche-Comté COMUE (UBFC), Halophytes and C4 Plants Research Laboratory, Department of Plant Science, School of Biology, University of Tehran, Tehran, Iran., Franco-Iranian International Associated Laboratory project “HAOMA”, ANR-14-CE35-0026,PaleoPersepolis,The Persepolis Basin (SW Iran): a System Model to investigate Human-Climate-Ecosystem interactions during the Holocene(2014)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: Younger Dryas; climate change; Karst; lake-level change; Zagros; [SDE]Environmental Sciences; NGRIP
• Online Access: https://amu.hal.science/hal-02197624; https://amu.hal.science/hal-02197624/document; https://amu.hal.science/hal-02197624/file/Aubert%20et%20al%202019.pdf; https://doi.org/10.1139/cjes-2018-0256

International audience The late glacial-early Holocene transition is a key period in the earth's history. However, although this transition is well studied in Europe, it is not well constrained in the Middle East and palaeohydrological records with robust chronologies remain scarce from this region. Here we present an interesting hydrobiological record showing a major environmental change occurring in the Dasht-e Arjan Wetland (southwestern Iran, near to Persepolis) during the late glacial-early Holocene transition (ca. 11 650 years cal BP). We use subfossil chironomids (Insecta: Diptera) as a proxy for hydrological changes and to reconstruct lake-level fluctuations. The Arjan wetland was a deep lake during the Younger Dryas marked by a dominance of Chironomus plumosus/anthracinus-type, taxa adapted to anoxic conditions of deep waters. At the beginning of the Holocene, a drastic decrease (more than 80% to less than 10%) of Chironomus plumosus/anthracinus-type, combined with diversification of littoral taxa such as Polypedilum nubeculosum-type, Dicrotendipes nervosus-type, and Glyptotendipes pallens-type, suggests a lake-level decrease and a more vegetalized aquatic environment. We compare and contrast the chironomid record of Arjan with a similar record from northwestern Iran. The palaeoclimatic significance of the record, at a local and regional scale, is subsequently discussed. The increase in Northern Hemisphere temperatures, inferred by geochemical data from NGRIP, at the beginning of the Holocene best explains the change from the Younger Dryas highstand to early Holocene lowstand conditions in the Dasht-e Arjan wetland. However, a contribution of the meltwater inflow from small local glaciers in the catchment basin is not excluded. La transition tardiglaciaire-Holocène précoce représente une période clé de l'histoire de la terre. Si cette transition est bien étudiée en Europe, ce n'est toutefois pas le cas au Moyen-Orient, et les profils paléohydrologiques associés à des chronologies robustes demeurent ...