TY - JOUR

T1 - Upper Kimmeridgian to Lower Tithonian foraminifers and ostracods of the Boulonnais region, Northern France. Stratigraphic and palaeoenvironmental implications and inter-regional correlations with the Siberian arctic

AU - Colpaert, C. P.A.M.

AU - Nikitenko, B.

AU - Danelian, T.

AU - Elena, Fursenko

AU - Igor, Kosenko

N1 - Funding Information: We wish to express our sincere gratitude to Jessie Cuvelier and Thierry Oudoire, curators respectively at the University of Lille and the Museum of Natural History of Lille, for providing us access to the palaeontological collections they are in charge of and for help with some specific literature; we are also grateful to Dr. S. Maillet for help during field work at the Cran du Noirda Section. Pr. N. Tribovillard (Univ. Lille) and Pr. J.F. Deconinck (Univ. Bourgogne) provided valuable comments and suggestions. Constructive remarks by the two anonymous reviewers helped greatly improve the initial manuscript. The University of Lille sponsored a visiting professorship to B. Nikitenko in late 2015, which allowed to conduct joint fieldwork in the Boulonnais Region. This study was financially supported by the Russian Science Foundation (grant n° 18-17-00038), by the Strategic Priority Research Program of Chinese Academy of Sciences ( XDB26000000 ) and by the National Natural Science Foundation of China ( 41572006 , 41688103 , 41972007 ). Publisher Copyright: © 2021 Elsevier B.V. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/4

Y1 - 2021/4

N2 - The well-exposed Upper Kimmeridgian to Lower Tithonian sequences of the Boulonnais Region (Northern France) are revisited with an integrated litho-, bio- and chemostratigraphic study of the Cran du Noirda (CDN) and Pointe de la Crèche (PDC) sections. Three foraminiferal and two ostracods zones are identified and tied to the ammonite zones previously established in the Boulonnais. The Upper Kimmeridgian Pseudolamarckina pseudorjasanensis foraminifera Zone is of particular interest, as we establish that it may be recognized in very distant regions throughout the Subboreal, Boreal, and Arctic provinces. The comprehensive analysis of the TOC content and Rock Eval pyrolysis allows to underline the deposition of a Lower Tithonian Organic-Rich Interval (ORI) associated with the wheatleyensis – scitulus (p.p.) ammonite zones. Furthermore, the palaeoecological analysis of the identified foraminiferal assemblages suggests the occurrence of four dysoxic events during the Late Kimmeridgian to Early Tithonian. Foraminiferal assemblages with genera adapted to low-oxygen conditions are present in intervals with high values of δ13CTOC. During the Late Kimmeridgian to Early Tithonian, organic-rich deposits are widespread across the Western European Archipelago and the Laurasian Seaway. The establishment of hypoxic conditions above the sea-floor was favoured by high marine productivity and stratification of the water column. Conversely, periods of low relative sea-level resulted in the redeposition of sediments from the margins into the basin, while water depth was insufficient to allow the development of reduced conditions.

AB - The well-exposed Upper Kimmeridgian to Lower Tithonian sequences of the Boulonnais Region (Northern France) are revisited with an integrated litho-, bio- and chemostratigraphic study of the Cran du Noirda (CDN) and Pointe de la Crèche (PDC) sections. Three foraminiferal and two ostracods zones are identified and tied to the ammonite zones previously established in the Boulonnais. The Upper Kimmeridgian Pseudolamarckina pseudorjasanensis foraminifera Zone is of particular interest, as we establish that it may be recognized in very distant regions throughout the Subboreal, Boreal, and Arctic provinces. The comprehensive analysis of the TOC content and Rock Eval pyrolysis allows to underline the deposition of a Lower Tithonian Organic-Rich Interval (ORI) associated with the wheatleyensis – scitulus (p.p.) ammonite zones. Furthermore, the palaeoecological analysis of the identified foraminiferal assemblages suggests the occurrence of four dysoxic events during the Late Kimmeridgian to Early Tithonian. Foraminiferal assemblages with genera adapted to low-oxygen conditions are present in intervals with high values of δ13CTOC. During the Late Kimmeridgian to Early Tithonian, organic-rich deposits are widespread across the Western European Archipelago and the Laurasian Seaway. The establishment of hypoxic conditions above the sea-floor was favoured by high marine productivity and stratification of the water column. Conversely, periods of low relative sea-level resulted in the redeposition of sediments from the margins into the basin, while water depth was insufficient to allow the development of reduced conditions.

KW - Benthic Foraminifera. Ostracods. Biostratigraphy. Biofacies. Organic-Rich Intervals. Late Jurassic. Boulonnais Region. France

UR - http://www.scopus.com/inward/record.url?scp=85103388350&partnerID=8YFLogxK

U2 - 10.1016/j.marmicro.2021.101976

DO - 10.1016/j.marmicro.2021.101976

M3 - Article

AN - SCOPUS:85103388350

VL - 164

JO - Marine Micropaleontology

JF - Marine Micropaleontology

SN - 0377-8398

M1 - 101976

ER -