0000000000371282
AUTHOR
Jean Marie Rouchy
Sedimentary, stable isotope and micropaleontological records of paleoceanographic change in the Messinian Tripoli Formation (Sicily, Italy)
Abstract The Tripoli Formation (6.96–5.98 Ma) of the Central Sicilian Basin provides a good record of the paleoceanographical changes that affected the Mediterranean during the transition from slightly restricted conditions to the onset of the Messinian Salinity Crisis. The Falconara/Gibliscemi section has been selected for an integrated approach at a high resolution scale using sedimentology, stable isotopes of the carbonates and microfossils. The sedimentary succession includes 46 precession-controlled cycles resulting from the periodical increase in biosiliceous productivity (diatomites) that followed the deposition of marls and pinkish laminites, which appear as sapropel-type deposits i…
Reconstruction of the paleoenvironmental changes around the Miocene-Pliocene boundary along a W-E transect across the Mediterranean
Abstract In order to reconstruct the environmental changes at the end of the Messinian salinity crisis, a multidisciplinary study has been carried out with a high sampling resolution of the late Messinian–early Zanclean (Zone MPl 1) sediments along a West–East Mediterranean transect. The studied examples comprise sections from southern Spain (Vera/Almanzora), Balearic Basin (ODP Site 975), Tyrrhenian Basin (ODP Site 974), Sicily (Eraclea Minoa), Zakynthos (Kalamaki), Corfu (Aghios Stefanos), Crete (Aghios Vlasis). Previously analyzed sections from the Levantine Basin (Cyprus and ODP Sites 968 and 969) are used for comparison. The sections have been correlated using planktonic foraminiferal …
Formation of secondary carbonates and native sulphur in sulphate-rich Messinian strata, Sicily
Abstract Microbially formed authigenic carbonates accompanied by native sulphur are present in the ‘Calcare Solfifero’ below a thick succession of gypsum deposited during the Messinian salinity crisis in Sicily. We sampled these carbonates and associated sulphur in five former sulphur mines to subject them to a detailed petrographic and geochemical study in order to explore their different modes of formation. Native sulphur formed in conjunction with microbial sulphate reduction, which is reflected in its depletion in 34S (δ34S values as low as − 2‰ vs. V-CDT) and an enrichment of 34S in the residual sulphate (δ34S values as high as + 61‰). The oxidation of organic matter by sulphate reduct…
The late Messinian "Lago-Mare" event and the Zanclean Reflooding in the Mediterranean Sea: New insights from the Cuevas del Almanzora section (Vera Basin, South-Eastern Spain)
Abstract The return to normal marine conditions in the Mediterranean Sea after the end of the Messinian Salinity Crisis (MSC), that led to the deposition of thick evaporitic succession followed by settlement of brackish to freshwater conditions of the “Lago-Mare”, is still subject to extensive debate between two opposite scenarios. One scenario implies an abrupt reflooding through the Gibraltar gateway of the Mediterranean Sea previously disconnected from the world ocean and partly desiccated. The second scenario postulates that the Mediterranean Sea kept a high-water level throughout the Messinian Salinity Crisis and was connected continuously to the Atlantic Ocean and to the Paratethys. T…
The Messinian salinity crisis in the Mediterranean basin: A reassessment of the data and an integrated scenario
Abstract After a long period of controversial debate about the interpretation of the Messinian salinity crisis (MSC), a near consensus existed since the ODP Leg 42A for a model keeping the major lines of the deep basin-shallow water model initially proposed by Hsu et al. (1973) . The knowledge of the crisis was improved since the 1995s by the availability of a very accurate astronomically calibrated timescale. The debate about its interpretation was then reactivated by several new scenarios that questioned most the major aspects of the previous classical models. The updated re-examination of the most salient features along with consideration of the hydrological requirements for evaporite de…
The onset of the Messinian salinity crisis: Insights from Cyprus sections
Abstract The Neogene basins of Southern Cyprus provide a good opportunity to improve the knowledge of the paleoenvironmental changes involved in the triggering of the Messinian evaporite deposition in the Mediterranean, and of their chronology, which is still questionable with regards to the parameters responsible for the triggering of the salinity crisis. It is still difficult to discriminate the individual effects of tectonics, climate, global sea-level changes. In Cyprus, considerable progress has been made on the events leading to the MSC, since the 70's, in high-resolution microfossil biostratigraphy, astrochronology, cyclostratigraphy and magnetostratigraphy. A study of the Tochni sec…
Late Messinian to Early Pliocene paleoenvironmental changes in the Melilla Basin (NE Morocco) and their relation to Mediterranean evolution
Abstract Three major paleoenvironmental changes have been recognized during the late Miocene to Early Pliocene in the Melilla Basin (Northeastern Morocco) and compared with the regional events that affected the Mediterranean hydrology during this crucial period. The first change was the definitive conversion of the restricted marine conditions that prevailed since the end of the reef carbonate complex into lacustrine environments; this occurred around 5.8 Ma which is earlier than in the rest of the Mediterranean where the Lower Evaporites were still forming. These lacustrine settings display great similarities with the Lago-Mare environments that started in the Mediterranean during the depo…
The end of the Messinian salinity crisis: Evidences from the Chelif Basin (Algeria).
How did the Messinian Salinity Crisis end is a matter of intense debate between two opposite concepts i.e., the generalised dilution event, the so-called Lago–Mare, followed by the sudden restoration of the marine conditions at the base of the Zanclean, or the early partial or complete marine refill that would have happened earlier during the upper Messinian. The Chelif Basin of Northwestern Algeria, one of the greatest Messinian marginal basins of the Mediterranean, provides an exceptional opportunity to study in detail how this major paleoenvironmental change occurred through continuous sedimentary records of the Miocene–Pliocene boundary. Five sections representative of both the central …
Transition from marine to hypersaline conditions in the Messinian Tripoli Formation from the marginal areas of the central Sicilian Basin
Abstract Three sections of the early Messinian Tripoli Formation from the northern and southern margins of the central Sicilian Basin (Serra Pirciata, Torrente Vaccarizzo, and Marianopoli) have been studied with the aim to reconstruct the sedimentary and environmental changes which occurred during the transition between marine conditions and the evaporitic events of the Salinity Crisis recorded in the overlying Calcare di Base Formation. A detailed biostratigraphic and cyclostratigraphic study provided the opportunity of cycle-by-cycle correlations between the marginal sections and the reference section of Falconara. The main paleoenvironmental changes are recorded by: (1) the evolution of …
Reply to the comment on “Carbonate deposition and diagenesis in evaporitic environments: The evaporative and sulphur-bearing limestones during the settlement of the Messinian Salinity Crisis in Sicily and Calabria” by Caruso et al., 2015. Palaeo3, 429, 136–162
Abstract Manzi et al. (in press) took the opportunity offered by our paper to repeat again all the set of ideas supporting an interpretative model of the Messinian Salinity Crisis (MSC), a model they assert to be valid for the whole Mediterranean basin. What emerges from reading this long comment may be summarized in one criticism of our article: we have not systematically applied their interpretative model to our data! The aim of our paper was not to promote their ideas, but to submit the results of more than 20 years of field studies and petrographical and geochemical analyses on Sicilian and Calabrian sequences of the Messinian “Calcare di Base”. It is out of our purpose to enumerate aga…
Sedimentary and diagenetic markers of the restriction in a marine basin: the Lorca Basin (SE Spain) during the Messinian
Abstract The Lorca Basin (southeastern Spain) is part of a chain of small marginal Neogene basins located in the structurally active Betic area. The Upper Miocene (Messinian) sequence is composed of a thick diatomite-bearing series (Tripoli Unit) overlain by the Main Evaporites, analogous to the classical succession that records the main events during the Salinity Crisis in the Mediterranean region. The shallow restricted conditions of this region amplified the sedimentary responses to local and global forcings. An integrated approach using sedimentology, micropalaeontology, stable isotope geochemistry and organic geochemistry has been applied to the Tortonian/Messinian succession of the Lo…