Thrust sequence and syntectonic sedimentation in a piggy-back basin: the Oligo-Aquitanian Mula–Pliego Basin (Internal Betic Zone, SE Spain)
The Oligo-Aquitanian deposits of the Mula–Pliego basin consist of a marine carbonate platform assemblage (bottom), transitioning into a turbidite wedge (top). This evolution was controlled by tectonics in a piggy-back basin by means of three main mechanisms: first, a flexural tectonic event created the basin; later on, blind-fault-propagation folds deformed it progressively from south to north; finally a tectonic event destroyed the basin. To cite this article: M. Martin-Martin, A. Martin-Algarra, C. R. Geoscience 334 (2002) 363–370.
Semi-allochthonous sedimentation in the Apenninic thrust belt
Abstract On-thrust sedimentation is not so common in mobile belts outside the Apennines. One of the relevant contributions to Apenninic geology by the florentine Giovanni Merla in the 1950's is the recognition of these traveller or “floating” sequences. This concept of semi-allochthon (as Merla called it) is reviewed here and discussed in the light of recent advances in stratigraphy and basin analysis. Several unconformities are detected in the sequence, which make it possible to split it into cycles or depositional sequences at variance with classical formations. Correlations have been attempted with sediments deposited behind and in front of the thrust belt; in comparison with foredeep flysch sequences, semi-allochthonous ones show better preserved stratigraphical relations (vertical stacking) and less deformation, which emphasizes their possible role as reference sections for syn-orogenic sedimentation in the Apennines.
Algunos aspectos de la estructura de la Zona Subbética (Cordilleras Béticas. España meridional)
Analysis of sedimentation and tectonics of the Subbetic zone of the Betic Cordilleras leads to the conclusion that sedimentation and subsequent deformation are largely governed by a Wilson cycle (Wilson, 1966, 1968) that began the opening of the Tethyan rift in the Pangaea continent during the Pliensbachian, 180 Ma ago. The resulting ocean began to close again in the Cretaceous, a process that led to a collision between Iberia and African elements in the Burdigalian, which was followed by strike-slip movement along a shear zone between the two plates which continues to this day. It is argued that the collision led to general uplift of the Subbetic zone as shown by the termination of deep water pelagic and hemipelagic sedimentation in the entire zone, and that the subsequent strike-slip movements along a system of anastomosing faults loo to very intense deformation localized along separate fault zones, and to the opening of pull-apart basins with characteristic sedimentation sequences.