Cretaceous oceanic anoxic event

Ohkouchi, N., Kashiyama, Y., Kuroda, Y., Ogawa, N. O., and Kitazato, H. (2006). The importance of diazotrophic cyanobacteria as primary producers during Cretaceous Oceanic Anoxic Event 2. Biogeosciences 3, 467—478. 

Kuypers M. M. M., Blokker P., Erbacher J., Kinkel H., Pancost R. D., Schouten S., and Sinninghe Damste J. S. (2001) Massive expansion of marine Archea during a Mid-Cretaceous oceanic anoxic event. Science 293, 92-94. 

Schlanger S. O. and Jenkyns H. C. (1976b) Cretaceous Oceanic Anoxic Events causes and consequences. Geologie En... 

Only reported from a mid-Cretaceous oceanic anoxic event nonhyperthermophilic marine Crenarchaeota ... 

Deposition of organic-rich sediments further down the shelf and on to the continental slope and rise often occurs as a result of turbidite flows, redistributing organic-rich sediments from delta fronts or from further up the shelf and slope (Summerhayes 1983). While there is a certain amount of pelagic sedimentation, primary production decreases away from the coastline as nutrient levels decline, and detritus is largely recycled before it settles to the sea floor. However, this may not always have been so in the past, when the thermohaline circulation (Box 3.2) did not operate and there may have been widespread anoxia in bottom waters, aiding preservation of sedimentary organic matter (e.g. Cretaceous oceanic anoxic events Section 6.3.4). 

Fig. 6.23 (a) Cretaceous oceanic anoxic events (OAEs) and their relationship to global isotopic trends (afterVeizer et al. 1999 Jones Jenkyns 2001 Leckie et al.2002) (b) 813Ccaibomte excursion associated with OAE2 in the Chalk ofEast Kent, UK (after Jenkyns et al. 1994). 

Erbacher J., Huber B.T., Norris R.D., Markey M. (2001) Increased thermohaline stratification as a possible cause for an ocean anoxic event in the Cretaceous period. Nature 409, 325-9. 

Jones C.E., Jenkyns H.C. (2001) Seawater strontium isotopes, oceanic anoxic events, and seafloor hydrothermal activity in the Jurassic and Cretaceous. Am.J. Sci. 301, 112-49. 

D) Pan-oceanic anoxic event. This occurs when polar glaciation is absent during episodes of uniform warm global temperature, such as may have occurred during the Cretaceous period. [From Selley, R. C. (1998). Elements of Petroleum Geology, 2nd ed., Fig. 5.8, Academic Press, San Diego.]... 

Figure 11.8 Isotopic composition of U in black shales from before, during, and after Ocean Anoxic Event 2 in the Late Cretaceous. Reproduced with permission from [68].

Jenkyns H. C. (1980) Cretaceous anoxic events from continents to oceans. J. Geol Soc. London 137, 171-188. 

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