Messinian erosional and salinity crises: View from the Provence Basin (Gulf of Lions, Western Mediterranean)

Abstract

International audienceThough the late Miocene “Messinian Salinity Crisis” has been intensely researched along the circum-Mediterranean basins, few studies have focused on the central part of the Mediterranean Basin and, especially, the pre-salt deposits. To improve our knowledge of the Messinian events, it is imperative to better understand this domain. In this study, we provide a more complete understanding of this central domain in the Provence Basin. We were able to recognize: a) thick marine detrital series (up to 1000 m) derived from the Messinian subaerial erosion which is partly prolongated in the distal part by b) a thick unit of deep marine deposits (up to 800 m) prior to the evaporites; c) a thick presumed alternation of detritals and evaporites (1500 m) below the mobile halite; and d) a two-step transgression at the end of the Messinian. Spatially, we document the eroded shelf to the deep basin (and from the western to the eastern parts of the Gulf of Lions), and temporally, we extend the interpretations from the early deposition of detritic sediments to the final sea-level rise. The results provide a new basis for discussion not only for the development of the Messinian Salinity Crisis but also for the reconstruction of the subsidence history of the Provence Basin

The Roussillon Basin (S. France): A case-study to distinguish local and regional events between 6 and 3 Ma

“…Mapping of this unconformity revealed a pattern of up to 5 th order dendritic drainage with two main systems ( Fig. 1) (Genesseaux and Lefebvre, 1980;Guennoc et al, 2000;Lofi et al, 2005;Bache et al, 2009). The two systems were mapped upstream in the Languedoc-Roussillon region and in the Rhône Valley where erosion is observed up to at least 350 km from the present coast (Clauzon, 1978(Clauzon, , 1979(Clauzon, , 1982.…”

“…A large part of the offshore MES had already been mapped and interpreted. Mapping revealed a pattern of up to 5 th order dendritic drainage (Gorini, 1993;Guennoc et al, 2000;Gorini et al, 2005;Bache et al, 2009;Lofi et al, 2011) with two main systems:…”

“…The MES is well studied offshore from the Gulf of Lions (Gorini, 1994;Guennoc et al, 2000;Lofi et al, 2003Lofi et al, , 2005Lofi et al, , 2011Bache et al, 2009) where Miocene sediments (below the unconformity) and Pliocene sediments (above the unconformity) were accurately dated by foraminifer biostratigraphy in several long boreholes (Cravatte et al, 1974). The corresponding stratigraphic gap was evidenced onshore in the Canet 1 and Elne 1 wells (Fig.…”

“…The two systems were mapped upstream in the Languedoc-Roussillon region and in the Rhône Valley where erosion is observed up to at least 350 km from the present coast (Clauzon, 1978(Clauzon, , 1979(Clauzon, , 1982. This unconformity is commonly interpreted as a subaerial erosional surface (the Messinian Erosional Surface) sculpted during the main MSC fall in sea level (Ryan and Cita, 1978;Guennoc et al, 2000;Lofi et al, 2005;Bache et al, 2009). The location of the seismic profile is shown in Figure 1.…”

Coastal Karst Groundwater in the Mediterranean: A Resource to Be Preferably Exploited Onshore, Not from Karst Submarine Springs

“…Rias and rocky inlets-named "calanques" in French-were created during this phase of erosion. Huge karst springs discharged at the foot of carbonate formations developing pocket valleys as shown by investigations along the French coast [25] and now completely plugged with Pliocene and Quaternary formations.…”