Tempestitas del Messiniense en la Cuenca del Bajo Segura (provincia de Alicante)

Resumen

The Bajo Segura Basin is located in the eastern area of the Betic Cordillera. During the Messinian it was a western mediterranean marginal sedimentary basin. The Messinian stratigraphic record comprises a shallowing-upward regressive megasequence resulting from the progradation o f coastal and shallow marine facies over evaporitic and pelagic basin facies. Three types of facies have been recognized and described: 1) mud dominated and lensing bedding; from offshore-nearshore transitional environments, 2) mixed, with wavy and flaser bedding from shoreface environments, and 3) sand dominated, mainly with tabular bedding, genetically interpreted as tempestites. These tempestites have different types of single and amalgamated sequences. The genesis of tempestites in the Bajo Segura Basin during the Messinian is a singular and distinctive aspect as contrasted as other western mediterranean marginal basins of the Betic Cordillera, and it is due to two main factors: I) the palaeogeographic context of the basin, extensively open to the Mediterranean, which allowed the direct influence of the storms on the coastal areas, and 2) the appropiate grain size of the sediments for a good development of the storm layers and the resultant sedimentary sequences.