Resumen de Caracterización sedimentaria de los volcanes de fango del Golfo de Cádiz: facies y procesos
María C. Fernández Puga, Celia María Martín Puertas, María Pilar Mata Campo, Juan Tomás Vázquez, Francisco Javier Hernández Molina, Víctor Díaz del Río Español, Luis Somoza, L.M. Pinheiro
Geophysical and sedimentological data collected on the continental slope of the Gulf of Cadizrevealed frequent areas with intense emissions of hydrocarbon-enriched fluids, which produced common mud volcano structure on the sea-floor. They are related with the ongoing movement and development of diapiric structure from the Cádiz Gulf Allochthonous Units. Gravity cores data on three mud volcanoes close to the Guadalquivir Diapiric Ridge (GDR) and two on the TASYO area have been studied in this work. Sedimentary facies, nature and thickness were studied in order to characterize each of them and to compare both GDR and TASYO areas. Two major different sedimentary facies have been identified: a) mud breccia facies and b) silts. The mud breccia facies are characterized by non-organize sediment generating as the upward fluids movements. The matrix ofthe mud breccia facies is made of gray to green muds. Its granulometric parameters shows two main granulometric poblations (6 & 9 ?) possibly related to two different sedimentary processes. Fine fraction (clay) can be produced by upward processes by fluids migration, but the coarse fraction (silt) are related to a detritic sedimentation coeval with the volcano activity generated by Con-tourite and/or turbidite sedimentary processes. The mud volcanism activity of the GDR seems to beolder than the mud volcanism activity of the TASYO area.
