Cretaceous oceanic anoxic event 2 triggered by a massive magmatic episode

  title={Cretaceous oceanic anoxic event 2 triggered by a massive magmatic episode},
  author={Steven C. Turgeon and Robert A. Creaser},
Oceanic anoxic events (OAEs) were episodes of widespread marine anoxia during which large amounts of organic carbon were buried on the ocean floor under oxygen-deficient bottom waters. OAE2, occurring at the Cenomanian/Turonian boundary (about 93.5 Myr ago), is the most widespread and best defined OAE of the mid-Cretaceous. Although the enhanced burial of organic matter can be explained either through increased primary productivity or enhanced preservation scenarios, the actual trigger… 

A volcanic CO2 pulse triggered the Cretaceous Oceanic Anoxic Event 1a and a biocalcification crisis

The Aptian Oceanic Anoxic Event 1a (OAE1a, ca.120 Ma ago) is one of the most prominent of a series of geologically brief intervals in the Cretaceous characterized by the deposition of organic

Earth science: Volcanic cause of catastrophe

Steven Turgeon and Robert Creaser establish a clear link between the onset of OAE2 and magmatism through a direct proxy, the seawater osmium isotope ratios recorded in organic-rich black shales.

Volcanic triggering of a biogeochemical cascade during Oceanic Anoxic Event 2

Several periods of global ocean anoxia punctuated the Cretaceous period. Marine-sediment chemistry indicates that extensive volcanism at the beginning of Oceanic Anoxic Event 2 released sulphur to

Transient cooling episodes during Cretaceous Oceanic Anoxic Events with special reference to OAE 1a (Early Aptian)

  • H. Jenkyns
  • Environmental Science, Geography
    Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
  • 2018
High-resolution studies of OAE 1a show at least three cooling episodes of probable global distribution, one of which is documented at high enough resolution to show correlation with an increase in carbon-isotope values that was probably due to a rise in the quantities of organic matter being buried globally, with consequent potential drawdown of atmospheric CO2 and/or reduction in volcanic input of this greenhouse gas.

A perturbed hydrological cycle during Oceanic Anoxic Event 2

The Late Cretaceous Oceanic Anoxic Event 2 (OAE2; ca. 94 Ma) was one of the largest global carbon cycle perturbations during the Phanerozoic. OAE2 represents an important, although extreme, case

Decoupling of the carbon cycle during Ocean Anoxic Event 2

The Cenomanian to Turonian boundary transition (ca. 95–93 Ma) represents one of the most profound global perturbations in the carbon cycle of the past 140 m.y. This interval is characterized by

Cretaceous oceanic anoxic events prolonged by phosphorus cycle feedbacks

Abstract. Oceanic anoxic events (OAEs) document major perturbations of the global carbon cycle with repercussions for the Earth's climate and ocean circulation that are relevant to understanding

Marine Os isotopic evidence for multiple volcanic episodes during Cretaceous Oceanic Anoxic Event 1b

It is concluded that ocean acidification caused by the massive release of CO2 through extensive volcanic episodes could have promoted the major planktonic foraminiferal turnover during OAE1b.



Cretaceous oceanic anoxic events: causes and consequences

Organic carbon-rich sediments are globally developed in pelagic sedimentary sequences of Aptian-Albian and Cenomanian-Turonian age. They formed in a variety of paleo-bathymetric settings including

Geochemical and climatic effects of increased marine organic carbon burial at the Cenomanian/Turonian boundary

Perhaps the most significant event in the Cretaceous record of the carbon isotope composition of carbonate1,2, other than the 1–2.5 ‰ negative shift in the carbon isotope composition of calcareous

The Cenomanian-Turonian Oceanic Anoxic Event, I. Stratigraphy and distribution of organic carbon-rich beds and the marine δ13C excursion

Summary Marine strata deposited during late Cenomanian and early Turonian time display lithological, faunal, and geochemical characteristics which indicate that significant parts of the world ocean

Potential links between ocean plateau volcanism and global ocean anoxia at the Cenomanian-Turonian boundary

The Cenomanian-Turonian boundary is marked globally by the extinction of marine invertebrates and an increase in the accumulation and preservation of organic carbon-rich sediments (black shales). The

A large and abrupt fall in atmospheric CO2 concentration during Cretaceous times

Marine carbonates and organic matter show a sharp increase in their 13C/12C isotope ratio at the Cenomanian/Turonian (C/T) boundary, in the Cretaceous period. This isotopic shift resulted from an

Nitrate reduction, sulfate reduction, and sedimentary iron isotope evolution during the Cenomanian‐Turonian oceanic anoxic event

onset of the OAE in Italy have unusually low bulk d 57 Fe values, unlike those found in the black shale (Livello Bonarelli) deposited during the oceanic anoxic event itself: These latter conform to

Tropical warming and intermittent cooling during the Cenomanian/Turonian oceanic anoxic event 2: Sea surface temperature records from the equatorial Atlantic

Oceanic anoxic event 2 (OAE-2) occurring during the Cenomanian/Turonian (C/T) transition is evident from a globally recognized positive stable carbon isotopic excursion and is thought to represent