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An emerging palaeoceanographic ‘missing link’: multidisciplinary study of rarely recovered parts of deep-sea Santonian–Campanian transition from Shatsky Rise

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journal contribution
posted on 21.06.2016 by A. Ando, S. C. Woodard, H. F. Evans, K. Littler, S. Herrmann, K. G. Macleod, S. Kim, B.-K. Khim, S. A. Robinson, B. T. Huber

The Cretaceous deep-sea record of the Santonian–Campanian transition is commonly interrupted by an extensive unconformity (representing <10 Myr of hiatus). The resultant palaeoceanographic gap can now be partly bridged by a recent short core of pelagic ooze from Shatsky Rise (Integrated Ocean Drilling Program (IODP) Site U1348), with precise multidisciplinary age constraints developed herein. New oxygen isotope data from very well-preserved benthic foraminifera, together with accurately compiled comparable benthic data from previous Pacific deep-sea sections, exhibit a large (c. +1‰) early Campanian shift. We propose the Santonian–Campanian climatic transition was not gradual but was the first major cooling step after sustained mid-Cretaceous hothouse conditions.