Asynchronous Antarctic and Greenland ice-volume contributions to the last interglacial sea-level highstand

The last interglacial (LIG; ~130 to ~118 thousand years ago, ka) was the last time global sea level rose well above the present level. Greenland Ice Sheet (GrIS) contributions were insufficient to explain the highstand, so that substantial Antarctic Ice Sheet (AIS) reduction is implied. However, the nature and drivers of GrIS and AIS reductions remain enigmatic, even though they may be critical for understanding future sea-level rise. Here we complement existing records with new data, and reveal that the LIG contained an AIS-derived highstand from ~129.5 to ~125 ka, a lowstand centred on 125–124 ka, and joint AIS + GrIS contributions from ~123.5 to ~118 ka. Moreover, a dual substructure within the first highstand suggests temporal variability in the AIS contributions. Implied rates of sea-level rise are high (up to several meters per century; m c−1), and lend credibility to high rates inferred by ice modelling under certain ice-shelf instability parameterisations

Reliability of sea level dating using Th/U method for mollusks from the west coast of the red sea and from the atlantic coast of the Moroccan high atlas

International audienc

The onset of the Messinian salinity crisis in the Eastern Mediterranean (Pissouri Basin, cyprus)

The Pissouri Basin in Cyprus contains one of the most suitable sedimentary successions with which to study the onset of the Messinian Salinity Crisis in the Eastern Mediterranean. Exposures along the new Paphos-Limassol motor-way near Pissouri exhibit distinct cyclic bedding which permits the construction of a chronology based on orbital tuning. Biostratigraphic results reveal 10 planktonic foraminifera events that have been astronomically dated in other Mediterranean sections, and as such provide an excellent first-order age control. Magnetostratigraphic results are in good agreement with the biostratigraphic data and show that all magnetic chrons between C4n.1n and C3An.1n are present. The pattern of sedimentary cycles generally fits well with the insolation curve. Astronomical tuning of the succession shows that the first gypsum bed at Pissouri overlies a 40-60 kyr stromatolite- bearing transitional interval and correlates with the amplitude increase in insolation at 5.96 Ma, as in the western Mediterranean. This indicates that the onset of evaporite precipitation was synchronous right across the entire Mediterranean Basin

Quaternary marine and continental sedimentation in the northern Red Sea and Gulf of Suez (Egyptian coast): influences of rift tectonics, climatic changes and sea-level fluctuations

International audienc

Integrated quantitative biostratigraphy of the latest Tortonian – early Messinian Pissouri section (Cyprus): an evaluation of calcareous plankton bioevents

A quantitative study was performed on planktonic foraminifera and calcareous nannofossils of the astronomically dated Late Miocene Pissouri section (Cyprus). Our results confirm the reliability of well-known planktonic foraminiferal events as Catapsydrax parvulus LO (Last Occurrence), sinistral coiling change of Globorotalia scitula, Globorotalia miotumida group FRO (First Regular Occurrence), Globorotalia nicolae FO (First occurrence) and LO, sinistral coiling change of Neogloboquadrina acostaensis and also of several important calcareous nannofossil events (Amaurolithus primus FO. Amaurolithus delicatus FO, Reticulofenestra rotaria FO and FCO). Integrated planktonic foraminifera and calcareous nannoplankton data contribute to an enhanced time resolution of the Tortonian - early Messinian interval in the Levantine basin, and contribute to detailed correlations throughout the Eastern Mediterranean. In addition, we compare methodologies commonly used in calcareous plankton biostratigraphy, and shortly outline sources of bias that can influence the results of stratigraphic studies