View in EDS

New mineralogical and organic carbon-isotope data from the Tithonian of Boulonnais (France) – relationship with the VOICE

Saved in:
Bibliographic Details
Title: New mineralogical and organic carbon-isotope data from the Tithonian of Boulonnais (France) – relationship with the VOICE
Authors: Deconinck, Jean-Francois, Amédro, Francis, Grabowski, Jacek
Source: Volumina Jurassica; Vol. 23 (2025): Volume XXIII; 77-90 ; 1731-3708 ; 1896-7876
Publisher Information: Volumina Jurassica
Publication Year: 2025
Collection: Geological Quarterly
Subject Terms: Tithonian, Jurassic/Cretaceous boundary, VOICE (VOlgian Isotope Carbon Excursion), global correlation, northern France
Description: As part of the research initiated by the Berriasian Working Group, we have conducted a detailed study of the Tithonian sedimentary successions of Boulonnais (northern France), given their interest as being deposits which are contemporaneous with the Kimmeridge Clay Formation (KCF) of Dorset (southern England), but situated in more proximal environments on the edge of the London-Brabant massif. The determination of d13Corg highlights a negative excursion of approximately –2‰ which probably corresponds to the VOICE (VOlgian Isotope Carbon Excursion). The chemostratigraphic data were correlated with the Geologic Time Scale using a compilation of orbital and magnetic stratigraphy. As in the KCF, the onset of this negative excursion occurs in the Pallasioides Zone (M21r to lower M21n). Further, a detailed study of the clay mineralogy shows an increase in the proportion of smectite at the expense of illite and kaolinite in the Albani Zone (M20r to lower M20n), which correlates with the lower part of the middle Volgian. This widespread mineralogical change marks the onset of the period of significant aridification which characterizes the Jurassic/Cretaceous boundary interval regionally. The onset of the aridification phase was nearly synchronous with, or slightly preceded the paleoceanographic changes in some Tethyan basins including the Nannofossil Calcification Event, stratification of water masses, and trace metal enrichments. All these environmental changes in the Alpine Tethys took place around the early/late Tithonian boundary, in the early M20n magnetochron.
Document Type: article in journal/newspaper
File Description: application/pdf; application/vnd.openxmlformats-officedocument.wordprocessingml.document; application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Language: English
Relation: https://vjs.pgi.gov.pl/article/view/34613/25906; https://vjs.pgi.gov.pl/article/view/34613/25907; https://vjs.pgi.gov.pl/article/view/34613/25908; https://vjs.pgi.gov.pl/article/view/34613
Availability: https://vjs.pgi.gov.pl/article/view/34613
Accession Number: edsbas.C3F07BBA
Database: BASE
Description
Abstract:As part of the research initiated by the Berriasian Working Group, we have conducted a detailed study of the Tithonian sedimentary successions of Boulonnais (northern France), given their interest as being deposits which are contemporaneous with the Kimmeridge Clay Formation (KCF) of Dorset (southern England), but situated in more proximal environments on the edge of the London-Brabant massif. The determination of d13Corg highlights a negative excursion of approximately –2‰ which probably corresponds to the VOICE (VOlgian Isotope Carbon Excursion). The chemostratigraphic data were correlated with the Geologic Time Scale using a compilation of orbital and magnetic stratigraphy. As in the KCF, the onset of this negative excursion occurs in the Pallasioides Zone (M21r to lower M21n). Further, a detailed study of the clay mineralogy shows an increase in the proportion of smectite at the expense of illite and kaolinite in the Albani Zone (M20r to lower M20n), which correlates with the lower part of the middle Volgian. This widespread mineralogical change marks the onset of the period of significant aridification which characterizes the Jurassic/Cretaceous boundary interval regionally. The onset of the aridification phase was nearly synchronous with, or slightly preceded the paleoceanographic changes in some Tethyan basins including the Nannofossil Calcification Event, stratification of water masses, and trace metal enrichments. All these environmental changes in the Alpine Tethys took place around the early/late Tithonian boundary, in the early M20n magnetochron.