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A review of the current knowledge of the crustal and lithospheric structure of the Valencia Trough Basin

2015; Spanish National Research Council; Volume: 126; Issue: 2 Linguagem: Inglês

2253-6167

C. Ayala, Montserrat Torné, Eduard Roca,

Geological and Geochemical Analysis

espanolEn este articulo se presenta una recopilacion de la estructura cortical y litosferica de la cuenca del Surco de Valencia y sus areas circundantes. En el se resumen los datos geofisicos mas relevantes adquiridos desde los anos setenta (sismica, gravimetria, geoide y flujo de calor). A continuacion, el trabajo se centra en la discusion acerca de la geometria y propiedades fisicas de la estructura cortical y litosferica actual obtenida a partir de los datos sismicos y de la modelizacion de campos potenciales, elevacion y flujo de calor, y su relacion con la evolucion geodinamica alpina del Surco de Valencia. Se discute las diferencias de los resultados de la modelizacion del limite litosfera-astenosfera, obtenidos utilizando diferentes metodologias asi como las caracteristicas que, bajo nuestro punto de vista, requieren un estudio mas detallado con el objeto de conocer el origen y evolucion del Surco de Valencia; cuales son las causas de la distinta estructura cortical observada en la region SO respecto a la region NE; de la asimetria que se observa; el origen de las variaciones de reflectividad de la corteza inferior; la fabrica del manto litosferico, caracterizada por unas velocidades de las ondas P anomalamente bajas; y sus propiedades fisicas. EnglishIn this paper, we review the current geophysical knowledge of the Valencia Trough Basin, and the surrounding areas. For this purpose, we summarize the most significant regional geophysical datasets acquired since the seventies to investigate the trough (seismic, gravity, geoid and heat flow data). We then focus on the discussion regarding the geometry and physical properties of the present day crustal and lithospheric structure derived from seismic images, as well as combined potential field modelling and their relationships with the Alpine geodynamic evolution of the Valencia Trough. Finally, we discuss the differences in the results regarding the geometry of the lithosphere-asthenosphere boundary obtained by different modelling approaches and the features that, in our view, require further investigation to unravel the true nature of the Valencia Trough, including what could have caused the differences between the crustal structure observed in the SW region compared to the NE region, the asymmetric style of thinning across the trough; the origin of the changes in the lower crustal reflectivity across the basin; the fabric of the uppermost mantle, characterized by anomalously low P-wave velocities; and the physical properties of the lithosphere mantle (density, Pwaves velocity, thermal conductivity, temperature distribution, mineralogical composition, etc.).