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

白垩纪-早新生代世界被温暖的条件和普遍缺乏冰盖所主导。古新世晚期-始新世早期气候变暖达到顶峰(EECO；~52-50 Ma)，随后是始新世中晚期的降温趋势，最终将地球推向今天的冰川状态。古新世晚期-始新世早期的长期升温也被几次短暂(约103-5年)的过热事件所打断。然而，对新生代全球气候演化的研究大多来自北半球或大西洋和印度洋体系的沉积物，缺乏南太平洋的记录，而南太平洋在早古近纪的热量输送中起到了重要作用。我们提出了晚白垩世至中始新世Mead Stream剖面(新西兰南岛)的磁地层学和岩石磁学综合研究，该剖面由650m暴露良好的远洋石灰岩、硅质岩和泥灰岩组成。Mead Stream部分提供了南太平洋高纬度地区最著名的晚白垩世-早古近纪海洋沉积物记录。利用古地磁反转的记录，将剖面与地磁极性时间尺度(GPTS)进行对比，得出沉积作用的年龄模型。岩石磁学结果与合作研究小组的古生物数据相结合，将给出一个完整的、按年代校准的沉积物物理和生物格架，这些参数的地层学变化将使我们能够阐明晚白垩世-早古近纪地球的气候和环境动力学。

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.