Rapid Resurgence of Marine Productivity After the Cretaceous-Paleogene Mass Extinction

Rapid Resurgence of Marine Productivity After the Cretaceous-Paleogene Mass Extinction

Julio Sepúlveda (1,2,*)
Jens E. Wendler (3)
Roger E. Summons (4)
Kai-Uwe Hinrichs (1,2)

1 Organic Geochemistry Group, Department of Geosciences, and Center for Marine Environmental Sciences (MARUM), University of Bremen, 28334 Bremen, Germany.

2 International Graduate College–Proxies in Earth History (EUROPROX), University of Bremen, 28334 Bremen, Germany.

3 Research Group Geochronology–Basin Analysis, Department of Geosciences, University of Bremen, 28334 Bremen, Germany.

4 Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology (MIT), 45 Carleton Street, Cambridge, MA 02139, USA.

* To whom correspondence should be addressed. E-mail: juliosep@mit.edu


Abstract:

The course of the biotic recovery after the impact-related disruption of photosynthesis and mass extinction event at the Cretaceous-Paleogene boundary has been intensely debated. The resurgence of marine primary production in the aftermath remains poorly constrained because of the paucity of fossil records tracing primary producers that lack skeletons. Here we present a high-resolution record of geochemical variation in the remarkably thick Fiskeler (also known as the Fish Clay) boundary layer at Kulstirenden, Denmark. Converging evidence from the stable isotopes of carbon and nitrogen and abundances of algal steranes and bacterial hopanes indicates that algal primary productivity was strongly reduced for only a brief period of possibly less than a century after the impact, followed by a rapid resurgence of carbon fixation and ecological reorganization.