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
{"title":"Radioisotopic chronology of Ocean Anoxic Event 1a: Framework for analysis of driving mechanisms.","authors":"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","DOIUrl":null,"url":null,"abstract":"<p><p>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 <i>Leupoldina cabri</i> 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.</p>","PeriodicalId":21609,"journal":{"name":"Science Advances","volume":"10 47","pages":"eadn8365"},"PeriodicalIF":11.7000,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11578182/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Science Advances","FirstCategoryId":"103","ListUrlMain":"https://doi.org/10.1126/sciadv.adn8365","RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/11/20 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"MULTIDISCIPLINARY SCIENCES","Score":null,"Total":0}
引用次数: 0
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.
期刊介绍:
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