2024年11月20日 · Ocean Anoxic Event 1a (OAE1a) is characterized by worldwide deposition of organic-rich sediments, biotic crises, accelerated evolution of marine organisms, and abrupt carbon isotope anomalies in marine and continental carbonate and organic matter, reflecting one of the largest perturbations of the global carbon cycle and climate system of the ...

2024年3月26日 · The volcanic episode that formed Ontong Java Nui (OJN) in the western Pacific ~ 120 million-year-ago is thought to have triggered Oceanic Anoxic Event (OAE) 1a, yet the cause-effect relationship...

2024年9月4日 · Here we show that rapid ocean deoxygenation during OAE1a is linked to volcanic CO 2 emissions and the crossing of an associated climate threshold, after which the sluggish pace of the...

The Selli Event, also known as OAE1a, was an oceanic anoxic event (OAE) of global scale that occurred during the Aptian stage of the Early Cretaceous, about 120.5 million years ago (Ma). [1] The OAE is associated with large igneous province volcanism and an extinction event of marine organisms driven by global warming, ocean acidification , and ...

2021年3月31日 · This study aims to understand the influence of OAE1a on the terrestrial sediment and might also provide a reference for the impact of current lakes on the greenhouse effect through comprehensive...

2008年7月15日 · Orbital control allows us to estimate the duration of unique, globally identifiable stages of OAE1a. Although OAE1a had a duration of ~ 1.0 to 1.3 Myr, the initial perturbation represented by the negative carbon-isotope excursion was rapid, lasting for ~ 27–44 kyr. This estimate could serve as a basis for constraining triggering mechanisms ...

2016年12月1日 · Carbon isotope measurements of the TOC show a negative δ 13 C excursion of 4.5‰ followed by a positive excursion of 6.7‰ within a 20-m interval, identified as the early Aptian Oceanic Anoxic Event 1a (OAE1a). This isotopic pattern of the excursion is in perfect agreement with excursions from lower latitude sections of the same age.

2024年11月20日 · 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.

2020年1月15日 · Earth system model constraints on OAE 1a carbon emissions sources and fluxes. Modest organic carbon-like emissions initiated the negative carbon isotope excursion. Thereafter massive emissions from a mantle-like source responsible for p CO 2 increase. New Os record & modelling confirm OAE 1a onset precedes onset of large-scale volcanism.

白垩纪古海洋中分别在Aptian-Albian、Cenomanian-Turonian和Coniacian-Santonian期间发生多次大洋缺氧事件(Oceanic Anoxic Events,OAEs),分别被称为OAE1、OAE2和OAE3,而OAE1又可以划分为OAE1a,1b,1c和1d四次,其中OAE1a和OAE2达到全球规模。