 |
| Titel |
Orbital control on carbon cycle and oceanography in the mid-Cretaceous greenhouse time |
| VerfasserIn |
Martino Giorgioni, Helmut Weissert, Stefano M. Bernasconi, Peter A. Hochuli, Rodolfo Coccioni, Christina E. Keller |
| Konferenz |
EGU General Assembly 2011
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250050961
|
|
|
|
|
|
| Zusammenfassung |
| We established a new high-resolution carbonate carbon isotope record of the Albian interval of the Marne a Fucoidi Formation (Central Apennines, Italy), which were deposited on the southern margin of the western Tethys Ocean. This isotopes record is one of the most detailed and continuous available for the Albian stage and shows a prominent 400kyr cyclicity, which can be linked to Milankovitch’s long eccentricity.
The mid-Cretaceous, and especially the Albian, ocean-climate system is known to be highly sensitive to orbital variations. Milankovitch’s orbital cycles are expressed both in the lithology and in other proxies in several sedimentary archives (e.g. Dean et al, 1977; Herbert & Fischer, 1986; Grippo et al, 2004; Prokoph & Thurow, 2001; Kössler et al, 2001). However, they mainly reflect precession and short eccentricity, which seem to be more important on the local/regional scale, but too rapid for being clearly recorded in the global oceanic carbon reservoir. In pelagic sediments carbonate carbon isotope data are a useful proxy for detecting paleoceanographic signals at global scale, our results suggest that orbital changes had an impact on the global oceanic carbon reservoir at timescales of 400kyr under the mid-Cretaceous greenhouse conditions.
Long eccentricity cycles have been observed in carbon isotope records of the Cenozoic and the Quaternary (e.g. Pälike et al, 2006; Wang et al, 2010) and can be compared with our new results of the mid-Cretaceous. This comparison allows us to test the response of the carbon cycle to orbital forcing under very different climatic conditions, from the mid-Cretaceous greenhouse to the Quaternary icehouse.
References:
Dean W. E., Gardner J. V., Jansa L. F., Cepek P., Seibold E. - Cyclic Sedimentation along the continental margin of Northwest Africa - Initial Reports of the Deep Sea Drilling Project, vol. 51, 1977
Grippo, A., Fischer, A.G., Hinnov, L.A., Herbert, T.H., and I. Premoli Silva I. - Cyclostratigraphy and chronology of the Albian stage (Piobbico core, Italy) - in: Cyclostratigraphy: Approaches and Case Histories, edited by B. D’Argenio et al., Spec. Publ. SEPM Soc. Sediment. Geol., 81, 57–8, 2004
Herbert T. & Fischer A. - Milankovitch climatic origin of mid-Cretaceous black shale rhythms in central Italy - Nature, vol. 321, June, 1986
Kössler P., Herrle J., Appel E., Erbacher J., Hemleben C. - Magnetic records of climatic cycles from mid-Cretaceous hemipelagic sediments of the Vocontian Basin, SE France – Cretaceous Research, vol. 22, n. 3, pp. 321-331, 2001
Pälike H., Norris R. D., Herrle J. O., Wilson P. A., Coxall H. K., Lear C. H., Shakleton N. J., Tripati A. K., Wade B. S. - The Heartbeat of the Oligocene Climate System - Science, vol. 314, pp. 1894-1898, 2006
Prokoph A. & Thurow J. - Orbital forcing in a "Boreal" Cretaceous epeiric sea: high-resolution analysis of core and logging data (Upper Albian of the Kirchrode I drill core - Lower Saxony basin, NW Germany) - Palaeogeography Palaeoclimatology Palaeoecology, vol. 174, pp. 67-96, 2001
Wang P., Tian J., Lourens L. J. - Obscuring of long eccentricity cyclicity in Pleistocene oceanic carbon isotope records - Earth and Planetary Science Letters, v. 290, pp. 319-330, 2010 |
|
|
|
|
|
|