A multi-proxy record of the Latest Danian Event at Gebel Qreiya, Eastern Desert, Egypt

The Latest Danian Event (LDE) is a proposed early Palaeogene transient warming event similar to the Paleocene–Eocene Thermal Maximum, albeit of smaller magnitude. The LDE can be correlated with a carbon isotope excursion (‘CIE-DS1’) at Zumaia, Spain, and the ‘top Chron C27n event’ defined recently from ocean drilling sites in the Atlantic and Pacific, supporting a global extent. Yet, records of environmental change during the LDE (e.g. warming and sea-level fluctuations) are still rare. In this study, we focus on the micropalaeontology (calcareous nannofossils and benthic foraminifera), mineralogy and trace element geochemistry of the LDE in the Qreiya 3 section from the southern Tethyan margin in Egypt. In this section, the LDE is characterized by the occurrence of anomalous beds intercalated within upper Danian shales and marls. The event beds of the LDE are situated above an unconformity on top of a shallowing-upwards sequence deposited in a well-oxygenated outer neritic to upper bathyal marine palaeoenvironment. The lower LDE bed is barren of benthic foraminifera, but contains pyrite and fish remains, and is interpreted as an anoxic level formed during rapid relative sea-level rise. Incursion of a <em>Neoeponides duwi</em> (Nakkady, 1950) benthic assemblage in LDE bed II is interpreted as repopulation of the seafloor after anoxia. The sea-level cycle associated with the LDE is estimated at about 50 m maximum in the Qreiya 3 section. The environmental changes at Qreiya 3 are of supra-regional extent, since a similar sequence of events has been observed at other southern Tethyan locations.

最新达宁期事件（Latest Danian Event, LDE）是一种被提出的古近纪短暂升温事件，其特征与古新世-始新世极热事件（Paleocene–Eocene Thermal Maximum）相似，但幅度更小。LDE可与西班牙祖马亚剖面的碳同位素偏移“CIE-DS1”，以及近期在大西洋和太平洋大洋钻探站位中定义的“顶部C27n正向极性亚带事件”相对比，佐证了其全球分布范围。然而，目前关于LDE发生期间环境变化（如升温与海平面波动）的记录仍较为匮乏。本研究聚焦于埃及特提斯南缘Qreiya 3剖面中LDE的微古生物学（钙质超微化石与底栖有孔虫）、矿物学及微量元素地球化学特征。该剖面中的LDE以发育于上达宁期页岩和泥灰岩之间的异常岩层为特征。LDE的事件岩层位于一套形成于富氧外陆架至半深海上部古海洋环境的向上变浅序列顶部的不整合面之上。LDE的下部岩层不含底栖有孔虫，但含有黄铁矿与鱼类遗体，被解释为快速相对海平面上升过程中形成的缺氧层。LDE第二层中出现的*Neoeponides duwi*（Nakkady, 1950）底栖组合，被认为是缺氧事件后海底生境的生物复苏。在Qreiya 3剖面中，与LDE相关的海平面波动幅度最大约为50米。Qreiya 3剖面记录的环境变化具有超区域范围，因为在其他特提斯南缘剖面中也观测到了类似的事件序列。