Estructuras sedimentarias de deformación en el Mioceno superior-Cuaternario de la Cordillera Bética

Resum

Several outcrops of soft-sediment deformation structures produced by liquefaction, fluidization, and thixotropy have been analysed in late Miocene to Quaternary deposits from the Betic Cordillera. The recognized structures formed by gravitational readjustment in sediments with a reversed density gradient by liquidization (liquefaction, fluidification and thixotropy). Most are load structures which have been classified, by a morphologic point of view, as follows: load casts s. s., sag type, dome like, irregular, drop type, ball-and-pillow, and vergent load casts. In general, the morphology of these structures is independent of the genetic mechanism; different genetic mechanisms yielded similar load structures. The genetic mechanism capable of deforming the sediment could be connected with the own sedimentary environment (storm waves, overloading, unequal loading, etc.) or could be the result of an agent externa! to the sedimentary environment (mainly earthquakes). Its interpretation can only be unravelled through a detailed facies analysis.