The Radiolarian biotic response during OAE2. A high-resolution study across the Bonarelli level at Bottaccione (Gubbio, Italy)

Musavu-Moussavou, Benjamin; Danelian, Taniel; Baudin, François; Coccioni, Rodolfo; Fröhlich, François

doi:10.1016/j.revmic.2007.07.002

Cited by 33 publications

(8 citation statements)

References 40 publications

(101 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This event begins in the H. helvetica biozone, about 10 m above the top of the Bonarelli Level, a distinctive 90 cm thick marker bed composed of alternating thin black shale and gray radiolarite layers corresponding to OAE2 and the Cenomanian-Turonian Boundary (e.g., Tsikos et al, 2004;Coccioni and Luciani, 2005;Musavu-Moussavou et al, 2007). The sediments are otherwise unremarkable limestones of the R1 formation of the Scaglia Rossa Formation (Montanari et al, 1989).…”

Section: K3 Intervalmentioning

confidence: 99%

A record of the extraterrestrial 3He flux through the Late Cretaceous

Farley

Montanari

Coccioni

2012

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

Section: K3 Intervalmentioning

confidence: 99%

A record of the extraterrestrial 3He flux through the Late Cretaceous

Farley

Montanari

Coccioni

2012

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

“…By contrast, the global redox conditions prior to and following the OAE remain less known, although several studies have suggested reduced oceanic oxygenation prior to the event (Lu et al ., ; Westermann et al ., ; Zhou et al ., ; Owens et al ., ). This possibility is particularly relevant as the observed turnover of radiolaria began well before the event, biotic turnover of microfossil groups just before the onset of the OAE (Coccioni et al ., ) and the main biotic turnover recorded in the middle of the Bonarelli Level (Erbacher & Thurow, ; Musavu‐Moussavou et al ., ). The decline of other fossil groups during the OAE has been attributed to an expansion of anoxic and euxinic conditions that were unfavourable and even toxic to life (Leckie et al ., ; Snow et al ., ).…”

Section: Introductionmentioning

confidence: 97%

“…The physical and chemical oceanographic changes during the OAE resulted in evolutionary turnover of marine organisms, including molluscs (Elder & Kirkland, ; Elder, ), calcareous nannofossils (e.g. Bralower, ; Erba, ), radiolarians (Erbacher et al ., ; Erbacher & Thurow, ; Musavu‐Moussavou et al ., ) and benthonic and planktonic foraminifera (e.g. Leckie, ; Kaiho & Hasegawa, ; Premoli Silva & Sliter, ; Leckie et al ., ; Parente et al ., ).…”

Section: Introductionmentioning

confidence: 99%

Patterns of local and global redox variability during the Cenomanian–Turonian Boundary Event (Oceanic Anoxic Event 2) recorded in carbonates and shales from central Italy

et al. 2017

View full text Add to dashboard Cite

Careful evaluation of the local geochemical conditions in past marine settings can provide a window to the average redox state of the global ocean during episodes of extensive organic carbon deposition. These comparisons aid in identifying the interplay between climate and biotic feedbacks contributing to and resulting from these events. Well‐documented examples are known from the Mesozoic Era, which is characterized by episodes of widespread organic carbon deposition known as Oceanic Anoxic Events. This organic carbon burial typically leads to coeval positive carbon‐isotope excursions. Geochemical data are presented here for several palaeoredox proxies (Cr/Ti, V, Mo, Zn, Mn, Fe speciation, I/Ca and sulphur isotopes) from a section exposed at Furlo in the Marche–Umbrian Apennines of Italy that spans the Cenomanian–Turonian boundary. Here, Oceanic Anoxic Event 2 is represented by a ca 1 m thick radiolarian‐rich millimetre‐laminated organic‐rich shale known locally as the Bonarelli Level. Iron speciation data for thin organic‐rich intervals observed below the Bonarelli Level imply a local redox shift going into the Oceanic Anoxic Event, with ferruginous conditions (i.e. anoxic with dissolved ferrous iron) transiently developed prior to the event and euxinia (i.e. anoxic and sulphidic bottom waters) throughout the event itself. Pre‐Oceanic Anoxic Event enrichments of elements sensitive to anoxic water columns were due to initial development of locally ferruginous bottom waters as a precursor to the event. However, the greater global expanse of dysoxic to euxinic conditions during the Oceanic Anoxic Event greatly reduced redox‐sensitive trace‐metal concentrations in seawater. Pyrite sulphur isotopes document a positive excursion during the Oceanic Anoxic Event. Carbonate I/Ca ratios were generally low, suggesting locally reduced bottom‐water oxygen conditions preceding the event and relatively increased oxygen concentrations post‐event. Combined, the Furlo geochemical data suggest a redox‐stratified water column with oxic surface waters and a shallow chemocline overlying locally ferruginous bottom waters preceding the event, globally widespread euxinic bottom waters during the Oceanic Anoxic Event, followed by chemocline shallowing but sustained local redox stratification following the event.

show abstract

“…4) is composed mainly by dark clayey limestone and organic-rich black shales with abundant planktic foraminifera. These organic-rich deposits include siliceous beds with abundant radiolarians, an equivalent to "Livello Bonarelli" bed marker (Marcucci Passerini et al, 1991;Salvini and Marcucci Passerini, 1998;Premoli-Silva et al, 1999;Scopelliti et al, 2004;Musavu-Moussavou et al, 2007) Plate 2. 1 -Dictyomitra gracilis (SQUINABOL), 100µm, GA18.…”

Section: Oued Kharroub Sectionmentioning

confidence: 99%