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

古新世-早始新世被几次短暂的、持续时间约为20 - 200 ky的高温事件所打断，其中古新世-始新世热极大期（PETM）最为突出。突然变浅的溶跃层/CCD，负613 C漂移，和底栖动物的营业额都意味着在这些事件的海洋系统的重大扰动。我们最近在南特提斯大陆架的研究表明，在Danian-Selandian（DS）过渡期间，存在与海平面波动相关的额外超高温事件。独立地，几个深海地点包括一个粘土层（“Chron 27 n事件”），可能与特提斯的D-S事件有关。该项目的目的是破译古海洋学和古气候变化期间的D-S过渡在OOP腿165从加勒比海和腿171 B从西大西洋。这两个钻井现场提供了一个扩大和地层完整的古新世记录，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613 C和618 O化学地层学，以估计环境扰动和温度;（ii）通过矿物学代用指标约束古气候和古海洋学变化;以及（iii）通过生物地层学和稳定同位素将深海站点的D-S转换与特提斯域联系起来。

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.