New oxygen isotope evidence for long-term Cretaceous climatic change in the Southern Hemisphere

Journal article

A new composite δO record, generated from calcareous fine-fraction and bulk sediments from the Exmouth Plateau, details long-term Cretaceous climatic change at mid-latitudes in the Southern Hemisphere. Assessment of new and previously published δO data indicates that a mid-Cretaceous global climatic optimum was achieved sometime between the time of the Cenomanian-Turonian boundary and the middle Turonian, when surface-ocean paleotemperatures were the highest of the past 115 m.y. Periods of cooling and warming that reversed the general patterns were superimposed on long-term Aptian-Turonian warming and Turonian-Maastrichtian cooling trends, respectively. Extrapolation of Southern Hemisphere paleotemperature trends to Maastrichtian paleotemperature data from a low-latitude Pacific guyot implies that maximum mid-Cretaceous low-latitude paleotemperatures could have been in excess of 33 °C.

Authors: Clarke, L; Jenkyns, H

• Journal: Geology
• Volume: 27
• Issue: 8
• Pages: 699-702
• Publication date: 1999-08-01
• DOI: 10.1130/0091-7613(1999)027<0699:NOIEFL>2.3.CO
• ISSN: 0091-7613