Completing the Eocene cyclostratigraphy - new perspectives from a greenhouse world

我们的项目的目的是首次建立一个完整的旋回地层框架的基础上确定的稳定的长偏心周期为整个始新世（55至34马）的大西洋和太平洋在前所未有的分辨率。这两个海洋的预期年龄模型的准确性将允许非常详细的了解始新世温室气候变化的一般和过渡到一个较冷的晚古近纪气候状态。在这里提出的第三年，我们计划根据现在不断发展的，非常令人兴奋的结果来完善和扩展我们的记录。这些额外的分析对于实现我们项目的科学目标至关重要。新的磁性地层学数据涵盖了208站磁极性Chron C23和C24 n，以及确定磁极性Chron C18 n确切持续时间的额外稳定同位素数据，这些数据是完成始新世大西洋地层框架的关键记录。在我们项目正在进行的第一阶段非常有希望的结果的基础上，我们设想调查另外两个额外的，相对较短的高分辨率海底同位素记录的额外选定的间隔。这对于测试地球的气候是否通过一系列单独的步骤冷却而不是在始新世早期气候最佳期的极端温暖世界结束后逐渐冷却，这一点很重要始新世-渐新世过渡前超过1200万年。最终，整合和综合项目的所有磁，化学和旋回地层数据将大大有助于记录始新世中后期超热事件的发生和频率，了解它们与轨道强迫的关系，以及它们与温室气候动力学的关系。

The aim of our project is to establish a for the first time complete cyclostratigraphic framework based on the identification of the stable long eccentricity cycle for the entire Eocene (55 to 34 Ma) for both the Atlantic and Pacific oceans at unprecedented resolution. The accuracy of the intended age model for both oceans will allow very detailed insights into the Eocene greenhouse climate variability in general and the transition to a cooler Late Paleogene climate state. In the here proposed third year we plan to round-off and extend our records based on the right now evolving, very exciting results. These additional analyses are crucial to achieve the scientific objectives of our project. New magnetostratigraphic data covering magnetic polarity Chrons C23 and C24n at Leg 208 sites and additional stable isotope data to determine the exact duration of magnetic polarity Chron C18n are key records for completing the Eocene Atlantic stratigraphic framework. Built on the very promising results from the ongoing first phase of our project we envisage investigating additional selected intervals for two additional, relative short high-resolution benthic isotope records. This is important to test whether Earth´s climate cooled through a series of individual steps rather than gradually at the end of the long-term cooling following the extremely warm world of the Early Eocene Climate Optimum more than 12 million years before the Eocene - Oligocene transition. Ultimately, integrating and synthesizing all magneto-, chemo-, and cyclostratigraphic data of the project will substantially contribute to document the occurrence and frequency of middle to late Eocene hyperthermal events, understanding their relationship to orbital forcing, and their relationship to greenhouse climate dynamics.