TY - JOUR

T1 - The Maurynya section, West Siberia

T2 - a key section of the Jurassic-Cretaceous boundary deposits of shallow marine genesis

AU - Dzyuba, O. S.

AU - Pestchevitskaya, E. B.

AU - Urman, O. S.

AU - Shurygin, B. N.

AU - Alifirov, A. S.

AU - Igolnikov, A. E.

AU - Kosenko, I. N.

PY - 2018/7/1

Y1 - 2018/7/1

N2 - The Maurynya section exposed on the northwestern margin of West Siberia is one of few continuous sections of the Jurassic-Cretaceous boundary deposits in Boreal regions. In the meantime, it can be considered a reference section for the transitional Volgian-Ryazanian beds formed in shallow water environments of the West Siberian sea basin. This study is a synthesis of the new data with previous results of lithologic, paleontological, biostratigraphic, and (O, C, Sr) isotope studies of the Upper Volgian-lowermost Ryazanian of the Maurynya section. It has been established that the beginning of the Cretaceous (corresponding to the middle Late Volgian) is associated with a sharp increase in species number and diversity of cephalopods and bivalve mollusks on the northwestern margin of the West Siberian sea basin. This can be explained by an increase in its depths and their stabilization at a level which appeared optimal for the habitat of nekton, nektobenthos, and benthic fauna communities, superimposed on the general trend of warming. At the same time, the percentage of phytoplankton significantly increased, indicating the onset of transgression, which affected largely coastal landscapes and type of vegetation: The forests dominated by conifers were gradually succeeded by forests mostly composed of Ginkgoaceae.

AB - The Maurynya section exposed on the northwestern margin of West Siberia is one of few continuous sections of the Jurassic-Cretaceous boundary deposits in Boreal regions. In the meantime, it can be considered a reference section for the transitional Volgian-Ryazanian beds formed in shallow water environments of the West Siberian sea basin. This study is a synthesis of the new data with previous results of lithologic, paleontological, biostratigraphic, and (O, C, Sr) isotope studies of the Upper Volgian-lowermost Ryazanian of the Maurynya section. It has been established that the beginning of the Cretaceous (corresponding to the middle Late Volgian) is associated with a sharp increase in species number and diversity of cephalopods and bivalve mollusks on the northwestern margin of the West Siberian sea basin. This can be explained by an increase in its depths and their stabilization at a level which appeared optimal for the habitat of nekton, nektobenthos, and benthic fauna communities, superimposed on the general trend of warming. At the same time, the percentage of phytoplankton significantly increased, indicating the onset of transgression, which affected largely coastal landscapes and type of vegetation: The forests dominated by conifers were gradually succeeded by forests mostly composed of Ginkgoaceae.

KW - biodiversity

KW - lithology

KW - paleoecology

KW - paleotemperatures

KW - stratigraphy

KW - Volgian and Ryazanian Stages

KW - West Siberia

KW - JURASSIC/CRETACEOUS BOUNDARY

KW - RUSSIAN PLATFORM

KW - CARBON

KW - RIVER

KW - BELEMNITES

KW - NORTHERN-EAST-SIBERIA

KW - SEDIMENTARY BASIN

KW - NORDVIK PENINSULA

KW - LAPTEV SEA

KW - PALEOENVIRONMENTS

UR - http://www.scopus.com/inward/record.url?scp=85049986510&partnerID=8YFLogxK

U2 - 10.1016/j.rgg.2018.07.010

DO - 10.1016/j.rgg.2018.07.010

M3 - Article

AN - SCOPUS:85049986510

VL - 59

SP - 864

EP - 890

JO - Russian Geology and Geophysics

JF - Russian Geology and Geophysics

SN - 1068-7971

IS - 7

ER -