CALCAREOUS TEMPESTITES IN PELAGIC FACIES (JURASSIC, BETIC CORDILLERAS, SOUTHERN SPAIN)

Calcareous tempestite levels interbedded with Ammonitico Rosso and oth er related pelagic facies have been recognized. The previously describ ed examples of calcareous tempestites in pelagic facies are scarce. Th e studied outcrops are Middle and Late Jurassic in age and correspond to ancient sediments in the Southern Iberian Continental Paleomargin. These outcrops are now included in a notably deformed geological unit (External Subbetic) in the External Zones of the Betic Cordillera. The calcareous tempestites are calcarenite and calcisiltite beds, grainst one and packstone with peloids and bioclasts (mainly 'filaments' and S accocoma), showing an internal structure with hummocky cross-stratific ation. The deposits are thought to be formed by tropical storms and hu rricanes and their recurrence intervals have been estimated (200 ka in average). The presence of these calcareous tempestite levels and the symmetrical wave-ripples on the top of the beds are two important argu ments in favour of a palaeobathymetric interpretation of related pelag ic sediments in the sense that the deposition occurred below, but near to the storm wave base, and that calcareous tempestites are episodic resedimentation, mainly coincident with relative sea-level falls (lows tand phases); in which major storm waves affect the sea bottom.