The Catalan margin during the Messinian Salinity Crisis: Physiography, morphology and sedimentary record

17 pages, 12 figures

The Messinian Salinity Crisis (MSC) drastically affected the physiography, morphology and sedimentation all along the Mediterranean area at the end of the Miocene. This paper presents an analysis of the effects of the MSC on the Catalan continental margin, based on a broad database of seismic reflection profiles from the oil industry and academy. We study the sedimentary processes and their controlling factors and the correlation with the nearby and well-known Gulf of Lions. Because of the complexity of the MSC, we define the Margin Erosion Surface/Top Erosion Surface (MES/TES) as the surface marking the end of the Messinian event, which allows differentiating three domains along the Catalan margin: the Creus, Girona and Barcelona domains, separated by the Palamós and Blanes canyons. The Creus domain shows an important structural control on the MES/TES physiography, while the Girona and Barcelona domains are characterized by wide and flat MSC platforms below the present-day shelf. The entire margin developed a series of complex drainage systems as the result of the Messinian sea level drop. The location of the main valleys (Cap de Creus paleo-drainage system, Palamós and Blanes paleo-canyons and the downslope-trending valleys on the Barcelona domain) was directly controlled by the structural framework. In contrast, the Barcelona paleo-drainage system and the tributaries of the Blanes and Palamós systems were excavated by direct subaerial erosion by meteoric rain in the basins limited by basement blocks, and were afterwards totally filled by the Pliocene–Quaternary sedimentation. Regarding the MSC depositional features, the major part of the eroded sediment was deposited as detrital deposits on the foot of the slope. The distribution of detrital bodies and evaporites was also structurally controlled. A Zanclean sea level rise occurring in at least two phases is confirmed by this study, in correlation with interpretations from the Gulf of Lions

This study is mainly funded by an Institut Carnot-Ifremer-EDROME grant (for Marga Garcia) and also supported by the GDR and Action-Marges Mediterranée Occidentale (France). It also benefited from the 172 M. García et al. / Marine Geology 284 (2011) 158–174 support by the Projects TOPO-MED (CGL2008-03474-E/BTE), CONTOURIBER (CTM2008-06399-C04-04/MAR) and MONTERA (CTM2009-14157-C02), of the Ministry of Education and Science (Spain). The authors would like to thank the effort of the Instituto Geológico y Minero de España (IGME) for making their broad industry seismic data available to the public, and Marcel.li Farran (ICM-CSIC) for his help in the transformation of seismic profiles into digital data. We thank Seismic Micro-Technologies for providing the Kingdom- Suite software used for the seismic stratigraphy analysis. We are grateful to Eduard Roca (UB), Jean-Loup Rubino (TOTAL), François Bache (UPMC, CNRS) and Estelle Leroux (Université de Brest, Ifremer) for their help in the elaboration of this paper. We also thank the editors and reviewers (C. Bertoni and an anonymous reviewer) for their comments that greatly improved this paper

Peer reviewed