Latest Danian carbon isotope anomaly and associated environmental change in the southern Tethys (Nile Basin, Egypt)

Abstract

Abstract: During the Palaeocene and Eocene Epochs (65.5–33.9 Ma) the Earth experienced the warmest conditions of the Cenozoic. This Palaeogene greenhouse episode is characterized by several short-lived negative carbon isotope (δ 13 C) excursions, which are usually interpreted as transient warming events (‘hyperthermals') as indicated by rising temperatures of surface and bottom waters, and accompanied carbonate dissolution in deep-sea settings. Among these events, the Palaeocene–Eocene Thermal Maximum (PETM, c . 55.5 Ma) is globally the best documented and most prominent. Further negative δ 13 C anomalies have recently been identified in the Eocene, but the early to middle Palaeocene has mostly been neglected. Here, benthic foraminiferal δ 13 C records are presented from four upper Danian–lower Selandian sections in the Nile Basin (eastern Egypt). All records show a negative δ 13 C shift with an amplitude of up to 2‰ at the base of planktonic foraminiferal subzone P3b ( c . 61 Ma). The supra-regional nature of this event is emphasized by correlation with a well-dated, similar δ 13 C record from Zumaia (Spain). Lithological changes, the δ 13 C signature and biotic responses strongly resemble those of the PETM in Egypt, which leads to the hypothesis that this ‘Latest Danian Event' (LDE) may represent another early Palaeocene hyperthermal.