Kuypers, Marcel M. M.; van Breugel, Yvonne; Schouten, Stefan; Erba, Elisabetta; Sinninghe Damste, Jaap S. (2004): N (sub 2) -fixing cyanobacteria supplied nutrient N for Cretaceous oceanic anoxic events. Geological Society of America (GSA), Boulder, CO, United States, Geology (Boulder), 32 (10), 853-856, georefid:2004-082137

Abstract:

The abundance of specific membrane lipids, 2-methylhopanoids, indicates that cyanobacteria played a key role in the seemingly global deposition of black shales during the early Aptian (ca. 120.5 Ma) and late Cenomanian (ca. 93.5 Ma) oceanic anoxic events. Organic matter-rich sediments deposited during these events are characterized by a (super 15) N content typical of newly fixed N (sub 2) , indicating that cyanobacterial N (sub 2) fixation was the main source for nutrient N. We propose that denitrification and anaerobic ammonium oxidation effectively cut off the return of nutrient N from the anoxic deep waters to the photic zone in the oceans, giving N (sub 2) -fixing cyanobacteria a competitive advantage over algae during these oceanic anoxic events.

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West: -70.0143 East: 174.4004 North: 35.2940 South: 9.2714

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