Radioisotopic chronology of Ocean Anoxic Event 1a: Framework for analysis of driving mechanisms.

Li, Youjuan; Singer, Brad S; Takashima, Reishi; Schmitz, Mark D; Podrecca, Luca G; Sageman, Bradley B; Selby, David; Yamanaka, Toshiro; Mohr, Michael T; Hayashi, Keiichi; Tomaru, Taiga; Savatic, Katarina

doi:10.1126/sciadv.adn8365

Radioisotopic chronology of Ocean Anoxic Event 1a: Framework for analysis of driving mechanisms.

Li, Youjuan; Singer, Brad S; Takashima, Reishi; Schmitz, Mark D; Podrecca, Luca G; Sageman, Bradley B; Selby, David; Yamanaka, Toshiro; Mohr, Michael T; Hayashi, Keiichi; Tomaru, Taiga; Savatic, Katarina

Authors

Youjuan Li

Brad S Singer

Reishi Takashima

Mark D Schmitz

Luca G Podrecca

Bradley B Sageman

Professor David Selby phdjpop@durham.ac.uk
Professor

Toshiro Yamanaka

Michael T Mohr

Keiichi Hayashi

Taiga Tomaru

Katarina Savatic

Abstract

The timing, tempo, and causative mechanisms of Ocean Anoxic Event 1a (OAE1a), one of several such abrupt perturbations of the Mesozoic global carbon cycle, remain uncertain. Mudstones interbedded with tuffs in Hokkaido, Japan preserve carbon and osmium isotope shifts recording OAE1a. U-Pb zircon ages of tuffs constrain the OAE1a onset to 119.55 +0.072/-0.079 million years ago (Ma) and its duration to 1116 +87/-93 thousand years (kyr). Isotopic excursions of osmium followed by carbon that mark the rapid onset of OAE1a each lasted ~115 kyr. Critically, the occurrence of index fossil Leupoldina cabri in the Hokkaido OAE1a section, which also caps and thus postdate Ontong Java Plateau (OJP) basalts, has a U-Pb zircon age of ~118.7 to 118.4 Ma. Therefore, OJP volcanism remains a probable source of unradiogenic osmium and light carbon and a causative mechanism of OAE1a.

Citation

Li, Y., Singer, B. S., Takashima, R., Schmitz, M. D., Podrecca, L. G., Sageman, B. B., Selby, D., Yamanaka, T., Mohr, M. T., Hayashi, K., Tomaru, T., & Savatic, K. (2024). Radioisotopic chronology of Ocean Anoxic Event 1a: Framework for analysis of driving mechanisms. Science Advances, 10(47), Article eadn8365. https://doi.org/10.1126/sciadv.adn8365

Journal Article Type	Article
Acceptance Date	Oct 16, 2024
Online Publication Date	Nov 20, 2024
Publication Date	Nov 1, 2024
Deposit Date	Dec 4, 2024
Publicly Available Date	Dec 4, 2024
Journal	Science Advances
Electronic ISSN	2375-2548
Publisher	American Association for the Advancement of Science
Peer Reviewed	Peer Reviewed
Volume	10
Issue	47
Article Number	eadn8365
DOI	https://doi.org/10.1126/sciadv.adn8365
Public URL	https://durham-repository.worktribe.com/output/3116079
PMID	39565850