• journal_title：Geology
• Contributor：Maria Luisa G. Tejada ; Katsuhiko Suzuki ; Junichiro Kuroda ; Rodolfo Coccioni ; John J. Mahoney ; Naohiko Ohkouchi ; Tatsuhiko Sakamoto ; Yoshiyuki Tatsumi
• Publisher：Geological Society of America
• Date：2009-
• Format：text/html
• Language：en
• Identifier：10.1130/G25763A.1
• journal_abbrev：Geology
• issn：0091-7613
• volume：37
• issue：9
• firstpage：855
• section：Articles

The Early Cretaceous Ontong Java Plateau was emplaced at almost the same time as marine biotic changes that culminated in oceanic anoxic event 1 (OAE1a). A causative link between these events has been suggested, but direct evidence has been lacking until now. New Os isotope measurements across the Lower Aptian “Selli Level” black shale deposited during OAE1a in central Italy reveal two negative excursions in marine ¹⁸⁷Os/¹⁸⁸Os ratios within a period of 2 Ma starting above the Barremian-Aptian boundary and ending just above the Selli Level horizon, suggesting an order-of-magnitude increase in the global flux of unradiogenic Os. The results are consistent with early and major phases of eruption of the Ontong Java Plateau. The latter phase is estimated to have been as short as ~1 Ma and may have induced widespread oceanic stratification that triggered OAE1a.