Magnetostrategraphy and rock-magnetism of the Mead Stream section (Late Cretaceous - mid Eocene), New Zealand

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The Cretaceous–early Cenozoic world was dominated by warm conditions and the general absence of ice sheets. A late Paleocene–early Eocene climate warming culminated with the early Eocene climatic optimum (EECO; ~52–50 Ma), which was followed by a cooling trend over the middle–late Eocene that eventually drove the Earth to the present-day glacial condition. The late Paleocene–early Eocene long-term warming was also punctuated by several transient (~103–5 yr) hyperthermal events. However, most studies of Cenozoic global climate evolution are from sediments of the northern hemisphere or Atlantic and Indian Ocean systems, with a lack of records from southern Pacific Ocean, which played a fundamental role in the early Paleogene heat transport. We propose an integrated magnetostratigraphic and rock-magnetic study of the Late Cretaceous to middle Eocene Mead Stream section (Southern Island, New Zealand), which consists of 650 m of well-exposed pelagic limestone, chert, and marl. The Mead Stream section provides the best-known late Cretaceous–early Paleogene record of marine sediments in the high latitude of the southern Pacific Ocean. The record of paleomagnetic reversals will be used to correlate the sections with the geomagnetic polarity time scale (GPTS) and derive an age-model for the sedimentation. The rock-magnetic results, integrated with paleontologic data from collaborating research groups, will give a complete and chronologically calibrated physical and biological framework of the sediments, and the stratigraphic variations of these parameters will allow us to shed light on the late Cretaceous–early Paleogene Earth’s climate and environmental dynamics.