Доклады Академии наукДоклады Академии наук0869-5652The Russian Academy of Sciences1349110.31857/S0869-56524863336-340Research ArticleThe first results of tephrochronological investigations of the late pleistocene-holocene volcanic explosions in the valley of the Zhom-Bolok River (Eastern Sayan)ShchetnikovA. A.shch@crust.irk.ruBezrukovaE. V.shch@crust.irk.ruKerberE. V.shch@crust.irk.ruBelozerovaO. Yu.shch@crust.irk.ruKuz'minM. I.<p>Academician of the Russian Academy of Sciences</p>shch@crust.irk.ruIvanovE. V.shch@crust.irk.ruKrainovM. A.shch@crust.irk.ruFilinovI. A.shch@crust.irk.ruNechaevI. O.shch@crust.irk.ruInstitute of the Earth`s Crust of the Siberian Branch of the Russian Academy of SciencesVinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of SciencesIndustrial University of TyumenIrkutsk State University3005201948633363401706201917062019Copyright © 2019, Russian academy of sciences2019<p>This article presents first tephrochronological data on the volcanic activity in the valley of the Jom-Bolok River (East Sayan Mountains, Siberia), which is the largest manifestation of the Holocene eruptions in Central Asia. The data results from our study of the proglacial Kaskadnoe-1 Lake situated near the Jom-Bolok basalt field. The lake sediments include a series of tephra-rich layers. Radiocarbon dating of the lake sediments provided a robust age model which allowed us to build timing of eruptions formed the Jom-Bolok volcanic field. We recognize two large phases of volcanism separated by almost 5 thousand years dormant phase. The first phase is traced back to ca. 14.3 cal ka BP and lasted until 6.3 cal ka BP. Ten clusters of microtephra layers in the sediments of the first phase show 300-800 years recurrence of the volcanic events weakening upward. The event of 14.3-13.3 cal ka BP probably represents the strongest eruptions of the Jom-Bolok. The second phase started ca. 1.6 cal ka BP and highly likely continues in our days. Its strongest eruptions occurred between 1.6 and 0.8 cal ka BP with periodicity of 200 years. This tephrostratigraphy shows a multiplicity of the Jom-Bolok volcanic events and amplifies the earlier built scheme resulted from investigations of the stratified basalts, pyroclasts and lake damming events.</p>tephrochronologyHolocene volcanic activityEast Sayan Mountainsтефрохронологияголоценовый вулканизмВосточный Саян[Ярмолюк В.В., Никофоров А.В., Иванов В.Г. // Вулканология и сейсмология. 2003. № 5. С. 41-59.][Адамович А.Ф., Гросвальд М.Г., Зоненшайн Л.П. // Тр. Всесоюз. аэрогеол. треста. 1959 г. В. 5. С. 79-89.][Гросвальд М. Г. Развитие рельефа Саяно-Тувинского нагорья (оледенение, вулканизм, неотектоника). М.: Наука, 1965. 166 с.][Киселев А.И., Медведев М.Е., Головко Г.А. Вулканизм Байкальской рифтовой зоны и проблемы магмообразования. Новосибирск: Наука, 1979. 197 с.][Ivanov A.V., Arzhannikov S.G., Demonterova E.I., et al. // Bull. Volcanol. 2011. V. 73. P. 1279-294. Аржанников С.Г., Иванов А.В., Аржанникова А.В., и др. // Геология и геофизика. 2017. № 1. С. 27-47.][Безрукова Е.В., Щетников А.А., Кузьмин М.И. и др. // ДАН, 2016. Т. 468. № 3. С. 323-27.][Щетников А.А., Безрукова Е.В., Филинов И.А. и др. // География и природные ресурсы. 2016. № 3. С. 37-48.][Rose N.L., Golding P.E., Battarbee R.W. // Holocene. 1996. V. 6. P. 243-246.][Turney C.S.M. // J. Paleolimnology. 1998. V. 19. P. 199-206.][Blockley, S.P.E., Pyne-O’Donnell, S.D.F., Lowe, J.J. // Quatern. Sci. Rev. 2005. V. 24. P. 1952-1960.][Bronk Ramsey C. // Quatern. Sci. Rev. 2008. V. 27 (1-2). P. 42-60.][Bronk Ramsey C., Lee S. // Radiocarbon. 2013. V. 5 (2-3). P. 720-730.]