Age of the Jombolok lava field (East Sayan): evidence from dendrochronology and radiocarbon dating

S.G. Arzhannikov , A.V. Ivanov , A.V. Arzhannikova , E.I. Demonterova (1) , Marc Jolivet (2) , V.I. Voronin (3) , V.A. Buyantuev (3) , V.A. Oskolkov (3)

1 IEC - Institute of the Earth's Crust
2 GR - Géosciences Rennes
3 Siberian Institute of Plant Physiology and Biochemistry

Dendrochronology and radiocarbon dating, with reference to remote sensing, digital elevation modeling, geological, and geomorphological data, provide new age constraints for the Jombolok lava field in the East Sayan Mountains (Siberia). The Jombolok lava field originated in the latest Late Pleistocene and underwent at least four phases of volcanic activity recorded in lava flows. Two earliest phases followed shortly one after another more than 13 kyr ago. The third phase corresponding to eruptions of Kropotkin volcano can be timed only relatively. The fourth phase has been dated by dendrochronology and AMS 14C of well-preserved wood buried under the youngest lava which occurs among older lavas near the Jombolok River mouth. The age of this activity is bracketed between the death of trees caused by eruptions 1268-928 years ago and the beginning of new tree growth on the surface of the most recent lavas 900 years ago.

Mots clés: phases of volcanism; dendrochronology; radiocarbon dating; Jombolok lava field; East Sayan Mountains

Domaines: Sciences de la Terre

S.G. Arzhannikov, A.V. Ivanov, A.V. Arzhannikova, E.I. Demonterova, Marc Jolivet, et al.. Age of the Jombolok lava field (East Sayan): evidence from dendrochronology and radiocarbon dating. Геология и геофизика / Russian Geology and Geophysics, 2017, 58 (1), pp.20-36. ⟨10.1016/j.rgg.2016.07.001⟩. ⟨insu-01478301⟩