Oceanographic and climate changes during the Danian-Selandian transition in the West Atlantic: evidence for a hyperthermal event?

古新世-始新世早期时有几次-20-200Ky的瞬变高温事件，其中以古新世-始新世最热事件(PETM)最为突出。突然变浅的溶跃层/ccd，负613C漂移，以及底栖动物周转，都意味着在这些事件期间海洋系统发生了重大扰动。我们最近在南特提斯陆架的研究表明，在大年-塞拉迪亚(DS)转变期间，存在与海平面波动相关的额外超热事件。独立地说，几个深海遗址包括一个粘土层(“Chron 27n事件”)，它可能与特提斯的D-S事件有关。该项目旨在破译来自加勒比海的OOP航段165航段和来自西大西洋的171B航段D-S过渡期间的古海洋和古气候变化。这两个钻井地点都提供了扩大的和完整的古新世地层记录，包括不同的粘土层。高分辨率稳定同位素、沉积学、矿物学和生物地层学分析将用于(I)实现连续的613C和618O化学地层学来估计环境扰动和温度，(Ii)通过矿物学指标约束古气候和古海洋变化，以及(Iii)通过生物地层学和稳定同位素将深海遗址的D-S过渡与特提斯领域联系起来。

The Paleocene-early Eocene is punctuated by several transient, -20-200 ky lasting hyperthermal events of which the Paleocene-Eocene Thermal Maximum (PETM) was the most prominent. Abruptly shallower lysocline/CCD, negative 613C excursions, and benthic faunal turnover all imply a major perturbation of the ocean system during these events. Our recent research at the Southern Tethyan shelf suggests the presence of an additional hyperthermal event associated with sea-level fluctuations during the Danian-Selandian (DS) transition. Independently, several deep sea sites include a clay layer ("Chron 27n event") that may correlate with the D-S event in the Tethys. This project aims to decipher paleoceanographic and paleoclimatic changes during the D-S transition in the OOP Leg 165 from the Caribbean and Leg 171B from the Western Atlantic. Both drillsites provide an expanded and stratigraphically complete Paleocene record including distinct clay layers. High-resolution stable isotope, sedimentological, mineralogical, and biostratigraphic analysis will be applied for (i) achieving a continuous 613C and 618O chemostratigraphy for estimating environmental disturbances and temperatures, (ii) constraining paleoclimate and paleoceanographic changes by mineralogical proxies, and (iii) linking the D-S transition in the deep sea sites with the Tethyan realm by biostratigraphy and stable isotopes.