Quantification des flux sédimentaires et de la subsidence du bassin ...

tel-00790852, version 1 - 21 Feb 2013
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et al., 2006)). Cavazza and DeCelles (1998) proposed to refer this “additional sea-level rise”
to the isostatic readjustment resulting from the Mediterranean Basin reflooding. The time-
interval which separates the catastrophic reflooding in Sicily evidenced at the base of the
Arenazzolo Unit (estimated at 5.460 Ma; Bache et al., 2012) from the base of the Trubi
Formation (dated at 5.332 Ma; Van Couvering et al., 2000; Lourens et al., 2004), 128 kyrs, is
too long to be ascribed to the isostatic downlift which should be of the order of about ten
thousand years only if we refer to the relatively low amplitude sea-level rise of the Holocene
(Lambeck and Bard, 2000). Bache et al. (2012) preferred to consider the continuing global
sea level rise after the catastrophic reflooding to explain the wider inundation observed after
5.332 Ma around the Mediterranean.
6. Test by numerical modelling
In order to discuss the relevancy of the proposed scenario, several numerical experiments
have been performed. The aim of these numerical experiments is to test if the scenario is
reliable taking into account realistic hydro-climatic conditions. The results are not used to
support the scenario, but to illustrate the consistency of our interpretation of the geological
observations.
The tested numerical model allows to estimate a water and a salinity budget of the Western
Mediterranean Basin. As a complementary interest, it allows to predict the level of the
Mediterranean Sea and the evaporite thickness in the Western central Basin, an output that
can be compared with data. The method to perform such a numerical experiment is already
indicated in several studies (Blanc, 2000; Blanc, 2006; Gargani et al., 2008; Gargani and
Rigollet, 2007; Meijer, 2006; Meijer and Krijgsman, 2005) and details are also reported in the
supplementary material. Basically, the quantitative influence of the Atlantic sea-water inflow,
river discharge and rainfall is taken into account and counterbalanced by the rate of water
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