Neogene planktonic foraminifera are among the most widely used microfossils in the study of tempo and mode of evolution. Comparisons of taxonomic rates between the two major clades in this group have shown that the nonspinose globorotaliids have undergone a significantly more rapid evolutionary turnover than the spinose globigerinids (S. M. Stanley et al., 1988, Paleobiology 14, 235-249). In or...

The Palaeocene-Eocene thermal maximum (PETM) is characterized by a global negative carbon isotope excursion (CIE) and widespread dissolution of seafloor carbonate sediments. The latter feature supports the hypothesis that the PETM and CIE were caused by the rapid release of a large mass (greater than 2000Gt C) of 12C-enriched carbon. The source of this carbon, however, remains a mystery. Possib...

The chromium isotope system (53 Cr/52 Cr expressed as δ53 Cr relative to NIST SRM 979) is potentially a powerful proxy for the redox state of the ocean-atmosphere system, but a lack of temporally continuous, well-calibrated archives has limited its application to date. Marine carbonates could potentially serve as a common and continuous Cr isotope archive. Here, we present the first evaluation ...

Planktonic foraminifera (PF) shells comprise a significant fraction of the global oceanic carbonate flux and serve as primary archive history oceans. Yet, limited understanding their life cycles dynamics biological rhythms, hampers application palaeoceanographic proxies. Here, we present ten PF species shell-size distributions at daily timescale resolution in Gulf Aqaba (GOA), northern Red Sea....

the qom formation, a series of shales, sandstones and carbonate deposits, is the last transgression of the sea in central iran sedimentary basin. foraminifera are one of the most important and numerous fossil groups present in the qom formation. in this study, the micropaleontology of the qom formation in three measured stratigraphic sections in south and west of tafresh (rakin, band-e-ali nagh...

The Kometan Formation is widely spread in northeastern Iraq and mostly composed of deep marine carbonates, with a predominance planktonic foraminiferal assemblages throughout its sequences. Two outcrop sections, Smaquli Tabin, were chosen to study the biostratigraphy Formation. identified 32 species belonging 12 genera. According stratigraphic distribution relative foraminifera assemblages, dem...

Oxygen depletion in the upper ocean is commonly associated with poor ventilation and storage of respired carbon, potentially linked to atmospheric CO2 levels. Iodine to calcium ratios (I/Ca) in recent planktonic foraminifera suggest that values less than ∼2.5 μmol mol(-1) indicate the presence of O2-depleted water. Here we apply this proxy to estimate past dissolved oxygen concentrations in the...