Early Eocene nannofossil responses to climate change, Canterbury Basin, New Zealand

摘要

In order to have a better prediction of the response of calcareous nannoplankton to future climate change,we must study periods in the geological past that were warm with high CO_2 Similar conditions occurred during the early Eocene climatic optimum (EECO,~52-50 Ma), a warming event where global temperatures reached their Cenozoic peak and atmospheric CO_2 exceeded 1000 ppm. Our study examined calcareous nannofossil assemblages from two Canterbury Basin, New Zealand sections that span the lower to middle Eocene and include the EECO. The mid-Waipara River (northern Canterbury Basin) and Hampden Beach (southern Canterbury Basin) sections represent important records of Paleogene climatic change (Hollis et al., 2012). In this study, we investigated changes in calcareous nannofossil assemblages across the EECO and compared these changes to paleoceanographic parameters, such as sea-surface temperature (SST), to gain a better understanding of nannofossil responses to changes in environment.