Terminal Cretaceous Climate Change
Principal investigator: Prof J Francis
Sponsor: NERC
Value: £237072.17
Dates: 1st June 2005 to 31st May 2008
Summary
This project will investigate the nature of latest Cretaceous-early Tertiary climates in Antarctica. Geological evidence suggests that after the peak mid Cretaceous greenhouse warmth climates cooled considerably during the Maastrichtian (~71-65Ma). Some scientists now argue that cooling was at times so severe that polar regions suffered short term glaciation, causing sea level changes world-wide. This challenges the current view that the Cretaceous greenhouse world was ice-free, implying instead that short term glacial climates punctuated supposedly stable warm climates. Such dramatic environmental change would have stressed terrestrial and marine biotas and made them particularly susceptible to the global environmental catastrophe at the end of the Cretaceous.
Recent dating using strontium isotope stratigraphy has revealed that the Late Cretaceous sequence in the James Ross Basin, Antarctica is now the best sequence in the world in which to investigate Maastrichtian environments and climate change that led up to the Cretaceous/Tertiary (K/T) catastrophe. This Maastrichtian sequence a) is over 1150km thick, allowing very high resolution analysis, (b) contains a well-exposed section in which the K/T boundary occurs, c) provides a linked record of both terrestrial (palaeobotanical) and marine (stable isotope) climate change from the same section, d) is very well exposed and extremely fossiliferous with a wide range of microfossil and invertebrate taxa which are exceptionally well preserved, and e) now has a litho-, bio- and chronostratigraphic framework needed for global correlation
This project will exploit this exceptional sequence to obtain high resolution records of palaeontological, sedimentological, and geochemical signals to investigate the nature of latest Cretaceous-early Tertiary climate change at high latitudes, to test the hypothesis that ice was present at times, to determine the biological response to this environmental change in both terrestrial and marine high latitude ecosystems, and to understand the environmental context in which the K/T extinctions occurred.