Trends in organic matter deposition in the Cretaceous of the eastern Mediterranean: Revisiting and updating the chronology and facies of the Eratosthenes Seamount deposits

Abstract

In this study we revisited the Cretaceous of the Eratosthenes Seamount (ESM) from IODP LEG 160 Hole 967E, updating the chronology, depositional environment, and paleobathymetry of the ESM. Our goal was also to address the spatio-temporal distribution of organic matter and, by comparison with the eastern margins of the Levant Basin, discuss basin-wide controls on its deposition and preservation.The investigated core has a relatively continuous Cretaceous succession from the Aptian to the Danian. By identifying the Pα Zone we conclude that the base of the Paleocene is included in the 967E section. A total of 17 ages were identified, with low sedimentation rates of 0.04–2.37 cm/kyr. Petrographic analysis revealed pronounced differences, from micritic pellets, benthic foraminifera, algae, and mollusks in the bottom part of the core, to deep water facies in the uppermost Cretaceous. Paleobathymetry ranged between 0.5 and 5 m in the Aptian to 300–600 m in the Maastrichtian.Both high productivity and OMZ conditions prevailed during the Cenomanian–Turonian, as well as elsewhere in the eastern Mediterranean. While the low core recovery might affect reliable interpretation, we present two alternative explanations for the high vs. low organic content of the Campanian–Maastrichtian in the eastern Levant Basin vs. the ESM: (1) Location relative to upwelling cells; (2) Relative bathymetry, with the ESM representing a paleohigh for much of the Cretaceous, similar to the organic-poor anticline deposits in the eastern Levant, where the massive intervals of organic-rich carbonates accumulated only in the synclines of the Syrian Arc deformational belt.