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

Abstract

International audienceThe 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

The morpho-tectonic setting of the Southeast margin of Iberia and the adjacent oceanic Algero-Balearic Basin

“…1A and 2A) were fluvially eroded to create "badland" topography. It is at this time that evaporites were deposited in the deep basins (Clauzon et al, 2011;García et al, 2011;Lofi et al, 2005;Maillard et al, 2006;Rouchy and Caruso, 2006;Ryan, 1978;Ryan and Cita, 1978). Possibly it was at this time that the scarp east of the ramp was mantled by volcanic sediments, but we have no data to verify this.…”

Observing the past to better understand thefuture: a synthesis of the Neogene climate inEurope and its perspectives on present climatechange

“…Massive coastal erosion occurred due to the exposure of the coastal regions and the action of rivers led to the formation of great canyons, like the Rhone canyon and the ones found in the Nile Delta [113,114]. Upwelling phenomena occurred in the Guadalquivir basin, strongly fed by organic matter from rivers [117].…”

“…Coupled with a global mean sea level rise of 10 m, which was strongly influenced by the Mediterranean evaporation, this opening promoted the flooding of the Mediterranean by North Atlantic waters [113]. The Balearic, Corsica and Sardinia islands became isolated again [108,114,115]. This flooding marks the transition of the Messinian to the Zanclean age, which means, the transition from Miocene to the Pliocene (M/P) epoch, and the end of the MSC [108,114,115].…”

“…The Balearic, Corsica and Sardinia islands became isolated again [108,114,115]. This flooding marks the transition of the Messinian to the Zanclean age, which means, the transition from Miocene to the Pliocene (M/P) epoch, and the end of the MSC [108,114,115]. During the M/P, some thermophilic plants disappeared from the Mediterranean shores, like mangroves, probably due to the high salinity environment.…”

“…Even so, this epoch was warmer than today, even if it had a less or equal p CO2 compared to pre-industrial levels (≤ 390 ppm) [5]. During the Miocene several major important climatic events took place: the Miocene Climatic Optimum (MCO) [6,8,9], the beginning of the Arctic glacia-tion [4,10], the two European washhouse events [11,12] and the Messinian Salinity Crisis [13][14][15][16][17][18]. All these events induced changes in European climate, and the MCO appears as the first Neogene climate event with potential to be used as a climate analogue for future climate projections.…”