Long-term Aptian marine osmium isotopic record of Ontong Java Nui activity

Abstract The early to mid-Aptian was punctuated by episodic phases of organic-carbon burial in various oceanographic settings, which are possibly related massive volcanism associated with the emplacement Ontong Java, Manihiki, and Hikurangi oceanic plateaus southwestern Pacific Ocean, inferred have formed a single plateau called Java Nui. Sedimentary osmium (Os) isotopic compositions one best proxies for determining timing voluminous submarine volcanic episodes. However, available Os records during age limited narrow interval earliest Aptian, is insufficient reconstruction long-term hydrothermal activity. We document record using pelagic Tethyan sediments deposited Poggio le Guaine (Umbria-Marche Basin, Italy) precisely constrain episodes assess their impact on marine environment. Our new data reveal three shifts unradiogenic values, two correspond black shale horizons lower mid-Aptian, namely Wezel (herein named) Fallot Levels. These excursions ascribed inputs ocean through Combining published from lowermost Aptian organic-rich Gorgo Cerbara section Umbria-Marche it can be that Nui eruptions persisted ?5 m.y. mid-Aptian.