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

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

doi:10.1126/sciadv.adn8365

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

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

Geosciences Department

Research output: Contribution to journal › Article › peer-review

2 Scopus citations

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.

Original language	English
Article number	eadn8365
Journal	Science Advances
Volume	10
Issue number	47
DOIs	https://doi.org/10.1126/sciadv.adn8365
State	Published - 22 Nov 2024

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title = "Radioisotopic chronology of Ocean Anoxic Event 1a: Framework for analysis of driving mechanisms",

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.",

author = "Youjuan Li and Singer, {Brad S.} and Reishi Takashima and Schmitz, {Mark D.} and Podrecca, {Luca G.} and Sageman, {Bradley B.} and David Selby and Toshiro Yamanaka and Mohr, {Michael T.} and Keiichi Hayashi and Taiga Tomaru and Katarina Savatic",

note = "Publisher Copyright: Copyright {\textcopyright} 2024 The Authors, some rights reserved.",

year = "2024",

month = nov,

day = "22",

doi = "10.1126/sciadv.adn8365",

language = "English",

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TY - JOUR

T1 - Radioisotopic chronology of Ocean Anoxic Event 1a

T2 - Framework for analysis of driving mechanisms

AU - Li, Youjuan

AU - Singer, Brad S.

AU - Takashima, Reishi

AU - Schmitz, Mark D.

AU - Podrecca, Luca G.

AU - Sageman, Bradley B.

AU - Selby, David

AU - Yamanaka, Toshiro

AU - Mohr, Michael T.

AU - Hayashi, Keiichi

AU - Tomaru, Taiga

AU - Savatic, Katarina

PY - 2024/11/22

Y1 - 2024/11/22

N2 - 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.

AB - 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.

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DO - 10.1126/sciadv.adn8365

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VL - 10

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

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