The ultra-warm Arctic ca. 90 million years ago

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The geologic history of the Arctic region records past climatic conditions that can provide insight into modern conditions and the potential for future change. The focus of this proposed work is on an excursion within the Cretaceous greenhouse world to ultra-warm conditions, approximately 90 million years ago. Evidence for both high temperature and anomalous CO2 volcanic outgassing is found in the geology of the High Arctic. The former comes in the form of a spectacular assemblage of vertebrate fossils found on Axel Heiberg Island, including large-bodied crocodile-like champsosaurs, turtles and fish. The latter is inferred by the presence of continental flood basalts and the Alpha-Mendeleev Oceanic Ridge; these features may form one of Earth's most voluminous large igneous provinces. The investigators propose multidisciplinary studies in the High Arctic to improve understanding of the absolute age and paleotemperatures associated with the vertebrate fossils (carbon and oxygen isotope analyses) and the absolute age and duration of the anomalous volcanism (radiometric age and paleomagnetic analyses). With these data, the investigators will test prior interpretations calling for high mean annual temperatures without seasonal ice, and whether contemporaneous pulses of volcanic activity could have contributed to the inferred warming by altering atmospheric CO2. The work proposed will contribute to at least one Ph.D. thesis and will involve undergraduates who will receive field training in the High Arctic and in the laboratory. The investigators also propose outreach efforts including collaboration with local K-12 schools and the use of new media to disseminate results of their study to the general public.