Deep-sea Record of Mediterranean Messinian Events (dream)

Angelo Camerlenghi, Gert De Lange, Rachel Flecker, Daniel Garcia- Castellanos, Christian Huebscher, Johanna Lofi, Wout Krijgsman, Stefano Lugli, Vinicio Manzi, Terry McGenity, Giuliana Panieri, Marina Rabineau, Marco Roveri, and Francisco Sierro

The discovery of the Messinian evaporites in the Mediterranean is probably one of the major achievements of the DSDP program. During the 40 years that have passed since the formulation of Messinian salinity crisis (MSC) scenario, many works have been dedicated to this event. Analysis of the onshore outcrops, of offshore seismic records and scattered samples from DSDP and ODP drillings, as well as the substantial effort of climate, chemical and geophysical modelling, have however not been able to provide a unified conclusive interpretation of the Messinian event, so that causes and chronology of the MSC are not yet fully understood.

Certainly, the ongoing discussion is mainly linked to the fact that so far, due to technical limitations and safety issues (non-riser drilling vessel), only the few upper meters of the deep buried basin sequence has been recovered. The greater part of the Messinian succession that could provide a unique entire record of the MSC still lacks lithological and stratigraphical calibrations.

In 2007 a deep revision of the knowledge of the Messinian event was performed in Almeria (Spain). A number of open question were identified and the need for ultra-deep drilling was stressed as: “… effort must be made to identify drill sites that intersect the most complete evaporite sequences and those that retain their sedimentological characteristics, i.e. avoiding successions that have been strongly modified by salt flow”. In addition, many researchers suggested that, the full understanding of the Messinian event, will come from the drilling of different depositional settings, with specific emphasis on the Western versus Eastern basins.

In this context, the DREAM proposal has been submitted to the ECORD MagellanPlus Workshop Series Program. The purpose of DREAM is to organise in May 2013 a workshop gathering three generations of scientists (those who participated in the discovery, those who are presently actively involved in research, and the next generation) in order to identify locations for multiple-site drilling (including riser-drilling) in the Mediterranean Sea that would allow to solve the several open questions still existing about the causes, processes, timing and consequence at local and planetary scale of a outstanding case of natural environmental change in the recent Earth history: the Messinian salinity crisis (MSC).

The product of the workshop will be the identification of the embryonic structure of an experimental design of site characterization, riser-less an riser drilling, sampling, measurements, and down-hole experiments that will be the core for at least one compelling and feasible scientific proposal. Particular focus will be given to reviewing seismic site survey data available from different research groups at pan-Mediterranean basin scale, and on the need for additional site survey activity including 3D seismics.

AAPG Search and Discovery Article #90161©2013 AAPG European Regional Conference, Barcelona, Spain, 8-10 April 2013