TY - JOUR

T1 - Geological evidence of megafloods in the Upper Ob region

AU - Zolnikov, I. D.

AU - Filatov, E. A.

AU - Shpansky, A. V.

AU - Glushkova, N. V.

AU - Danilson, D. A.

AU - Bordyugova, E. A.

N1 - The study was carried out with the financial support of the Russian Scientific Foundation, project № 22-17-00140 "Late Quaternary history of the main valleys of Western Siberia". In conclusion, the authors express their gratitude to the reviewers, d.g.-m.s. V.I. Astakhov and d.g.-m.s. S.K. Krivonogov for valuable comments that made it possible to significantly improve the manuscript of the article.

PY - 2024

Y1 - 2024

N2 - The article is devoted to a critical analysis and revision of ideas about the geological structure, genesis and history of the formation of sediments filling the upper Ob valley from Biysk to the mouth of the Tom River. The formulation of the problem is due to the fact that existing ideas about the alluvial staircase of terraces, integrated with ideas about periglacial alluvium and giant glacial-dammed basins in the south of Western Siberia, contradict the accumulated volume of factual material. It is shown that in the Upper Ob region there are widely developed deposits of terraces V and IV, composed of Monastic and Biysk catafluvial strata. Each of them begins with boulder-pebbles with rounded blocks, is built on with cross-layered gravel sands with pebbles, and ends with parallel interlayered sands, silty sands, and silts. Their total thickness often exceeds 100 m. The Monastyrskaya sequence is correlated with the Ininskaya sequence of the Altai Mountains; its age is tentatively determined as the end of the Middle Neopleistocene. The Biyskaya sequence is correlated with the Saljar sequence of the Altai Mountains; its age is tentatively determined as corresponding to the second stage of the Upper Neopleistocene. The catafluvial breakthrough of the end of the last glacial maximum corresponds to the Bolsherechenskaya sequence (III4), the parallel layered sands of which in sections of the Upper Ob region reach 20 m in thickness. The Bolsherechenskaya sequence correlates with deposits of the Chibit glaciocomplex of the Altai Mountains. Facies-genetic and stratigraphic analogues of super-flood deposits of the Ob valley are deposits that fill ancient drainage basins that cut the Ob-Irtysh interfluve.

AB - The article is devoted to a critical analysis and revision of ideas about the geological structure, genesis and history of the formation of sediments filling the upper Ob valley from Biysk to the mouth of the Tom River. The formulation of the problem is due to the fact that existing ideas about the alluvial staircase of terraces, integrated with ideas about periglacial alluvium and giant glacial-dammed basins in the south of Western Siberia, contradict the accumulated volume of factual material. It is shown that in the Upper Ob region there are widely developed deposits of terraces V and IV, composed of Monastic and Biysk catafluvial strata. Each of them begins with boulder-pebbles with rounded blocks, is built on with cross-layered gravel sands with pebbles, and ends with parallel interlayered sands, silty sands, and silts. Their total thickness often exceeds 100 m. The Monastyrskaya sequence is correlated with the Ininskaya sequence of the Altai Mountains; its age is tentatively determined as the end of the Middle Neopleistocene. The Biyskaya sequence is correlated with the Saljar sequence of the Altai Mountains; its age is tentatively determined as corresponding to the second stage of the Upper Neopleistocene. The catafluvial breakthrough of the end of the last glacial maximum corresponds to the Bolsherechenskaya sequence (III4), the parallel layered sands of which in sections of the Upper Ob region reach 20 m in thickness. The Bolsherechenskaya sequence correlates with deposits of the Chibit glaciocomplex of the Altai Mountains. Facies-genetic and stratigraphic analogues of super-flood deposits of the Ob valley are deposits that fill ancient drainage basins that cut the Ob-Irtysh interfluve.

KW - Pleistocene

KW - Upper Ob

KW - new interpretation

KW - river deposits

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-86000554551&origin=inward&txGid=155d5db1bf267e84c16c1c45677dfaa2

UR - https://elibrary.ru/item.asp?id=80387961

UR - https://www.mendeley.com/catalogue/8bfde8d6-5fb6-37e5-b611-8c43233c288a/

U2 - 10.31857/S2949178924040023

DO - 10.31857/S2949178924040023

M3 - Article

VL - 55

SP - 13

EP - 26

JO - Геоморфология и палеогеография

JF - Геоморфология и палеогеография

SN - 2949-1789

IS - 4

M1 - 2

ER -