Sea floor morphology and Plio-Quaternary sedimentary cover of the Mallorca Channel, Balearic Islands, western Mediterranean

Abstract

A complete multibeam coverage of the sea floor of Mallorca Channel, in the western Mediterranean, was recorded during the Spanish Exclusive Economic Zone surveys in 1995, 1996 and 1997. These data, combined with previous high-resolution seismic reflection profiles, allow an assessment of the geomorphology of the area. The channel seafloor is disrupted by a fault complex and pockmarks. Motion along the faults split the sea floor into a series of undulations separated by narrow V-shaped notches. Faulting may be a consequence of recent seaward gravitational sliding that occurred along a soft surface at the top of a late Messinian -early Pliocene unit and a late Messinian evaporite. These units have been tilted during recent subsidence of the Mallorca Channel at the same time that the insular shelf was uplifted along a fault at the shelf's edge. The set of pockmarks in the channel sequence were probably formed by the expulsion of gas of hydrothermal origin, and expulsion may have been enhanced by the faulting. This gas seepage could be an additional factor leading to sediment instability. D

Synchronous onset of the Messinian evaporite precipitation: First Mediterranean offshore evidence

“…Similarly, seismic profiles reveal a post-evaporitic erosion surface, regarded as the Top BU Erosive Surface (e.g. Acosta et al, 2004;Driussi et al, in press;Maillard et al, 2006). Onshore and offshore paleontological data corroborate the erosion by indicating that the overlying marls were deposited during the early Pliocene (Corbi et al, 2010).…”

“…As part of the Betic Range, the BP suffered extensional tectonism during the late Miocene, which promoted the opening of several intramontane basins (e.g., Sorbas and Bajo Segura basins) ( Fig. 1A; Acosta et al, 2004;Maillard and Mauffret, 2013). Onshore and offshore MioQuaternary rocks were accumulated under similar tectonic settings related to the transpressive Eastern Betic Shear Zone (Alfaro et al, 2002).…”

“…Therefore their relative age cannot be established. Although BU facies resemble the ones of the Upper Unit (UU) from the Valencia basin (Lofi et al, 2011;Maillard et al, 2006), their current isolation prevents reliable correlations with the UU (Acosta et al, 2004;Driussi et al, in press).…”

“…2;Acosta et al, 2004;Driussi et al, in press;Maillard et al, 2014). The paleo-connections among these sub-basins during the MSC remain uncertain (Driussi et al, in press).…”

Assessment of the deep water trawl fishery off the Balearic Islands (western Mediterranean): from single to multi-species approach

“…Environmental information available was depth, hydrography (temperature, salinity and flow velocity near the bottom) obtained from a model and phytoplankton pigment concentration (ppc, mg Chl a/m 3 ), obtained from Kempler (2009), as indicator of the availability of Table 1 Summary of the environmental and fishery characteristics of each of the areas of the Balearic Islands analysed during the study, based on previous studies carried out in the study area (Pinot et al, 1995(Pinot et al, , 2002Acosta et al, 2002Acosta et al, , 2004López-Jurado et al, 2008;Monserrat et al, 2008;Serrano et al, 2008) trophic resources at the lowest levels of the trophic chain (Cartes et al, 2004). Data from different periods, simultaneously and before 1, 2, 3 and 4 months of the sampling, were considered.…”