About the WestMedFlux cruise

The Liguro-Provencal and Algero-Balearic basins are considered to be both formed by Oligocene-Miocene back-arc extension generated from the roll-back of the Tethys subducted oceanic crust (Fig. taken in Roure et al., 2012).

Heat flow profile of the young passive margins in the Gulf of Aden, illustrating the presence of persistent thermal anomaly under the OCT after continental breakup (Lucazeau et al., 2008).


While there is now a large consensus that Western Mediterranean basins developed in a Miocene back-arc setting due to slab roll-back and that some of it domains are floored by oceanic crust, there is still a lot of speculation on the configuration, nature and evolution of its margins and the ocean-continent transitions (OCT). A thick Messinian layer of evaporates in the deep basin obscures deep seismic reflectors, and only recently seismic refraction and wide-angle studies revealed a confident picture of basement configuration. In order to further constrain models of crustal structure and margin evolution, heat flow is one of the key parameters needed. Recent heat flow studies on other margins have shown the existence of a persistent thermal anomaly under rifted margins that urge to reconsider the classical models of its evolution. The young age of OCT and ceased oceanic formation in the Western Mediterranean make it an interesting test case for a thermo-mechanical study of its margins.


Heat flow data in the deep Mediterranean basin are, however, sparse and values are highly variable (50-200mW/m²). The presence of halokinetic structuring and salt diapirs urges the need of close spaced heat flow measurement to evaluate heat refraction and advective heat transfer by fluid migration. We therefore propose a set of new regional heat flow profiles crossing the Provencal basin and the Algero-Balearic basins, allowing to cover both conjugated margins and along-strike variations (transform faults, oceanic ages). Heat flow acquisition will be focussed along profiles well documented by seismic data and/or wells.  Near salt domes and mud volcanoes closely spaced heat flow measurements will be complemented with coring in order to analyse the role of fluids and salt on the thermal regime. This better understanding of small-scale heat transfers near the surface should allow us to extract the deep thermal signal from geodynamic origin.