The first carbon and oxygen isotope curves for the Valanginian to Early Barremian (Early Cretaceous) interval obtained from outcrops in the Southern Hemisphere are presented. They were obtained from well-dated (by ammonites) sediments from the Neuquén Basin, Argentina. Measurements were acquired by the innovative method of analysing fossil oyster laminae. The occurrence of the well-established mid-Valanginian positive carbon isotope excursion is documented, while less well-marked positive events may also correlate with peaks identified in the well-known successions of SE France. The mid-Valanginian positive carbon isotope event in the Neuquén Basin is possibly associated with organic-rich sediments. A similar relationship is seen in the European Alps and in oceanic cores in some areas of the world.
- carbon isotope
- oxygen isotopes
- early cretaceous
Aguirre-Urreta, M. B., Price, G. D., Ruffell, A. H., Lazo, D. G., Kalin, R. M., Ogle, N., & Rawson, P. F. (2008). Southern hemisphere early cretaceous (Valanginian-Early barremian) carbon and oxygen isotope curves from the neuquen basin, Argentina. Cretaceous Research, 29(1), 87-99. https://doi.org/10.1016/j.cretres.2007.04.002