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Showing 1 to 16 of 16 for “"oceanic anoxic event"”.
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Foraminiferal and stable isotope investigation of the Cenomanian-Turonian extinction and oceanic anoxic event
… of biota. At the time of the CTB a number of events occurred. Particularly well researched is the oceanic anoxic event (OAE 2) and the organic-rich black shales deposited during this interval. Associated with these organic-rich sediments is a positive carbon isotope anomaly. This excursion has …
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Towards an understanding of the carbon isotopic changes across the Toarcian oceanic anoxic event
… of the Toarcian (early Jurassic, 183 Ma) ocean anoxic event (OAE). In this study, we reveal that apparent negative isotopic excursions in bulk organic and carbonate carbon were the result of compositional changes of organic matter and diagenesis, respectively. Organic petrology and Rock-Eval …
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Biogeochemical Cycling and Paleoenvironmental Reconstructions of the Toarcian Oceanic Anoxic Event from Western North America
The Toarcian Oceanic Anoxic Event (T-OAE; ~183 million years ago) represents an interval during the Mesozoic when the emplacement of the Karoo-Ferrar Large Igneous Province (LIP) is thought to have resulted in significant environmental change. Associated with this interval was the widespread …
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Evaluating redox cycling across the Toarcian Oceanic Anoxic Event with implications for paleo-environmental reconstructions and organic matter sulfurization
… in habitability on Earth. Marine deoxygenation events, in particular, can result in changes in the carbon, sulfur, and iron cycles on our planet. Changes in these elemental cycles lead to distinctive variation in the chemical composition of seawater that is recorded in marine sediments that are …
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Geochemical signatures of black shales deposited during Oceanic Anoxic Event 2 (Cenomanian/Turonian) in the tropical Atlantic (Demerara Rise, ODP Leg 207) and in northern Germany (Wunstorf
Diese Studie präsentiert eine anorganisch-geochemische Untersuchung von zwei Sedimentabfolgen des Ozeanischen Anoxischen Ereignisses 2 (OAE 2) unterschiedlicher paläogeografischer Standorte. Am Demerara Rise (ODP Leg 207; tropischer Atlantik) sind die Sedimente, die während OAE 2 abgelagert wurden, …
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POPULATION DYNAMICS AND GEOCHEMISTRY OF BENTHIC AND PLANKTONIC FORAMINIFERA TO INTERPRET THE PALEOCEANOGRAPHIC CHANGES ACROSS THE CENOMANIAN-TURONIAN OCEANIC ANOXIC EVENT 2 AT LOW AND HIGH LATITUDES
… Earth’s history, namely the Cenomanian-Turonian Oceanic Anoxic Event 2 (OAE 2). It is globally marked by a positive δ13C excursion due to the deposition and burial of large amounts of organic matter in the ocean. The exact causes of OAE 2 are still studied but it is understood that it might be …
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High precision U/Pb geochronology on the Cenomanian Dakota Formation, Utah : implications for paleobotany and the transgression of the Western Interior Seaway preceding Oceanic Anoxic Event 2
The Dakota Formation was deposited during the Cenomanian, a time when the Western Interior Seaway spanned much of North America. The Dakota Formation contains a rich record of plant and animal fossils. Key to understanding their importance, it is imperative to precisely place the Dakota Formation …
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The Late Cenomanian Anoxic Event; implications for foraminiferal evolution
… investigates the effect of the late Cenomanian Oceanic Anoxic Event (OAE) on the planktonic and benthonic foraminifera. On the former, the OAE was the cause of major extinctions within the population, the return to pre-OAE oxygen levels permitting recolonization of the vacated niches. On the …
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High-precision U/Pb dating of the Cenomanian-Turonian boundary Kaiparowits Plateau, Utah
… Cenomanian-Turonian boundary is associated with Oceanic Anoxic Event 11 (OAE II) and is often identified by an increase of a13C in the carbon isotopic record. A high-precision chronology of the Cenomanian- Turonian boundary is needed to better constrain the cause, timing, and extent of OAE II. To …
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Cyclostratigraphy And Sedimentation Of The Cenomanian-Turonian Tuscaloosa Marine Shale
… rate, to identify and correlate the cretaceous oceanic anoxic event 2 (OAE 2) recovery period within the studied interval, and to determine the possible mechanisms of orbital forcing. Results from multitaper spectral analysis and average spectral misfit reveal multiple statistically significant …
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The impact of global environmental changes on exceptional preservation, extinction, and recovery in the early Jurassic (late Pliensbachian-Toarcian)
… are the Pliensbachian/Toarcian boundary event (~184.2 million years ago) and the Toarcian Oceanic Anoxic Event (TOAE, ~183 million years ago); these events represent two of the most severe environmental perturbations of the Early Jurassic Epoch, leading to marine ecosystem disruption and …
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The Aptian-Albian ironstone of the Rapid Creek formation, Little Fish Creek, NWT: implications for Cretaceous Ocean Anoxic Events and critical mineral deposits
… climate may have been important for producing anoxic seawater enriched in Fe and Mn to the Blow Trough. Such an interpretation implies that the Aptian-Albian Oceanic Anoxic Event (OAE) 1b may have been regional rather than global in extent. Other OAE may also have been more localized than …
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Applied palynology: Multidisciplinary case studies from Egypt, Gulf of Mexico and USA
… source rock intervals. The Cenomanian/Turonian oceanic anoxic event was identified within the Abu Roash "F" member. Palynofacies analysis of the offshore Gulf of Mexico section (DSDP Leg 10) enabled the recognition of two distinctive palynofacies units of mature organic matter content. The lower …
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U-Pb calcite dating of fossil eggshell and its impact on continental terrestrial sedimentology
… geochemical signature related to the Cretaceous Oceanic Anoxic Event 2, but nearly syndepositional uptake within the Tel Ulaan Chaltsai fossilized eggshells. In addition, Data Chapter 2 attempts to reinvestigate the sedimentological and geochemical aspects of Tel Ulaan Chaltsai to better place …
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Development of a Borehole Log Signature for Oceanic Anoxic Events and Its Application to the Gulf of Mexico
Oceanic anoxic events (OAEs) are periods in Earth's history when oceans were depleted in dissolved oxygen and characterized by deposition of organic-rich sediments. The Oceanic Drilling Program (ODP) has drilled through OAEs in a number of areas worldwide, collecting core and borehole log data. …
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PCO2 EFFECTS ON THE PRODUCTION OF PELAGIC BIOGENIC CARBONATE AND OCEAN CHEMISTRY: A CASE HISTORY FROM THE CRETACEOUS.
… under oxygen-poor conditions, named the Oceanic Anoxic Event 1a (OAE1a) (~120 Ma) which has its sedimentary expression in the Selli Level. OAE1a represents a profound perturbation of the ocean-atmosphere system caused by natural CO2 emissions related with climate change, ocean …