Oligocene to Middle Miocene basin development in the Velez Rubio Corridor - Espuna (Internal-External Zone Boundary; Eastern Betic Cordilleras, SE Spain)

The Velez Rubio Corridor and the area northwest of the Sierra Espuna are lo cated on the Internal-External Zone Boundary. The External Zone is represen ted by the Southern Subbetic, the most basinward part of the former passive margin of Iberia, the Internal Zone by its unmetamorphosed highest unit, t he Malaguide Complex, tectonically underlain by the metamorphosed Alpujarri de Complex. During the Oligocene and Aquitanian, the Southern Subbetic was the locus of slope deposition with northeastern provenance of detritus. In the Malaguides of the Espuna, the detritus of Lower Oligocene transgressive conglomerates and Middle Oligocene fan deltas indicates Sardinian proximit y. The Upper Oligocene to lower Aquitanian Ciudad Granada and Pliego format ions of the Malaguide Complex, carrying exclusively Malaguide detritus, wer e deposited in grabens within the Malaguide realm during an extensional rif ting phase. The Malaguides, still far removed from the Subbetic, underwent major thrusting during the Aquitanian. Of the sedimentary units found betwe en the Internal and External Zones, the oldest unit (the allochthonous Aqui tanian Solana formation) was deposited in submarine fans outside the Subbet ic or Malaguide realms proper, but in close connection with the latter. The Internal Zone collided with the External Zone in the early Burdigalian wit h concomitant disruption of the Southern Subbetic slope. On the suture, a d eep basin was formed and filled in by the Burdigalian Espejos formation car rying detritus from the Subbetic and from the Malaguide and Alpujarride Com plexes. In the late Burdigalian, the Subbetic was thrust southward over the Espejos formation, thus double-sealing the collisional contact. During the latest Burdigalian to Langhian, new basins were formed along the Internal- External Zone Boundary and within the Southern Subbetic. The onset of strik e-slip faulting caused shoaling and uplift of these basins. Onset of a new pattern of strike-slip faulting induced the formation of a new suite of bas ins during the Tortonian, e.g. the Lorca Basin.