Cryoturbation versus tectonic deformation along the southern edge of the Tunka Basin (Baikal Rift System), Siberia: New insights from an integrated morphotectonic and stratigraphic study

• Published in: Journal of Asian Earth Sciences
• Main Authors: Arzhannikova, Anastasia, Ritz, Jean-François, Larroque, Christophe, Antoine, Pierre, Arzhannikov, Sergey, Chebotarev, Aleksei, Stéphan, Jean-François, Marc Massault, M., Michelot, Jean-Luc
• Other Authors: Institute of the Earth's Crust (IEC), Siberian Branch of the Russian Academy of Sciences (SB RAS), Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud ), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: [SDE]Environmental Sciences; [SDU]Sciences of the Universe [physics]; permafrost; Siberia
• Online Access: https://hal.archives-ouvertes.fr/hal-02978189; https://doi.org/10.1016/j.jseaes.2020.104569

International audience The Tunka Basin is a broad, emerging basin situated between the Baikal Lake to the east and the the Hövsgöl Lake to the west. The basin is bounded to the north and to the south by the Tunka and the Khamar-Daban mountain ranges, respectively. The Tunka normal fault, located at the southern foothills of the Tunka mountain range, is the main structure that controlled the development of the Tunka Basin during the Neogene. Paleoearthquake-surface ruptures attest of its present activity; and show that its western and eastern terminations are undergoing a tectonic inversion characterized by left-lateral-reverse deformations. The southern edge of the Tunka Basin is classically interpreted as being tectonically controlled. In this paper, we present the results of a geomorphological and stratigraphic analysis within its southwestern and southeastern parts suggesting that there is no active fault affecting the foothills of the Khamar-Daban mountain range. The different features observed in the Quaternary deposits are interpreted to be the result of periglacial processes induced by alternating episodes of permafrost aggradation and degradation during the Holocene. Our study concludes that the Khamar-Daban Range and the Tunka Basin are uplifting together, and that the Tunka and Mondy faults are the two main triggers of regional earthquakes.