Status: this discussion paper is a preprint. It has been under review for the journal Climate of the Past (CP). The manuscript was not accepted for further review after discussion.
Maastrichtian carbon isotope stratigraphy and cyclostratigraphy of the Newfoundland Margin (Site U1403, IODP Leg 342)
Oliver Friedrich,Sietske J. Batenburg,Kazuyoshi Moriya,Silke Voigt,Cécile Cournède,Iris Möbius,Peter Blum,André Bornemann,Jens Fiebig,Takashi Hasegawa,Pincelli M. Hull,Richard D. Norris,Ursula Röhl,Thomas Westerhold,Paul A. Wilson,and IODP Expedition
MARUM, University Bremen, Leobener Strasse, 28359 Bremen, Germany
Paul A. Wilson
National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK
Abstract. Earth’s climate during the Maastrichtian (latest Cretaceous) was punctuated by brief warming and cooling episodes, accompanied by perturbations of the global carbon cycle. Superimposed on a long-term cooling trend, the middle Maastrichtian is characterized by deep-sea warming and relatively high values of stable carbon-isotope ratios, followed by strong climatic variability towards the end of the Cretaceous. A lack of knowledge on the timing of climatic change inhibits our understanding of underlying causal mechanisms. We present an integrated stratigraphy from Site U1403, providing an expanded deep ocean record from the North Atlantic (IODP Expedition 342, Newfoundland Margin). Distinct sedimentary cyclicity suggests that orbital forcing played a major role on depositional processes, which is confirmed by statistical analyses of high resolution elemental data obtained by X-ray fluorescence (XRF) scanning. Astronomical calibration reveals that the investigated interval encompasses seven 405-kyr cycles (Ma4051 to Ma4057) and spans 2.8 Myr directly preceding the Cretaceous/Paleocene (K/Pg) boundary. A high-resolution carbon-isotope record from bulk carbonates allows to identify global trends in the late Maastrichtian carbon cycle. Low-amplitude variations (up to 0.4 ‰), typical for open ocean settings, are compared to the hemipelagic Zumaia section (N-Spain), with a well-established independent cyclostratigraphic framework. Whereas the pre-K/Pg oscillations and the negative values of the Mid-Maastrichtian Event (MME) can be readily discerned in both records, patterns diverge around 67.5 Ma, with Site U1403 more reliably reflecting global climate change. Our new carbon isotope record and the established cyclostratigraphy from Site U1403 may serve as a future reference for detailed studies of late Maastrichtian events in the North Atlantic.
How to cite. Friedrich, O., Batenburg, S. J., Moriya, K., Voigt, S., Cournède, C., Möbius, I., Blum, P., Bornemann, A., Fiebig, J., Hasegawa, T., Hull, P. M., Norris, R. D., Röhl, U., Westerhold, T., Wilson, P. A., and IODP Expedition: Maastrichtian carbon isotope stratigraphy and cyclostratigraphy of the Newfoundland Margin (Site U1403, IODP Leg 342), Clim. Past Discuss. [preprint], https://doi.org/10.5194/cp-2016-51, 2016.
Received: 02 May 2016 – Discussion started: 18 May 2016
A lack of knowledge on the timing of Late Cretaceous climatic change inhibits our understanding of underlying causal mechanisms. Therefore, we used an expanded deep ocean record from the North Atlantic that shows distinct sedimentary cyclicity suggesting orbital forcing. A high-resolution carbon-isotope record from bulk carbonates allows to identify global trends in the carbon cycle. Our new carbon isotope record and the established cyclostratigraphy may serve as a future reference site.
A lack of knowledge on the timing of Late Cretaceous climatic change inhibits our understanding...