La sedimentación carbonatada del Lías en la transversal de Vélez Rubio (Subbético Interno)

Laburpena

The Lias of the Internal Subbetic in the Velez Rubio area can be subdivided in three depositional sequences, J.1, J.2 and J.3. Sequences J.1 and J.2 have been included in the Gavilan Formation and are formed by a very thick succesion of shallow water carbonates of Lower and Middle Lias age, respectively. The sequence J.3 has been found locally, below a thick oolitic limestone formation of the Dogger. The Lower Liassic Sequence (J.1) was deposited in a very wide pericontinental platform that bordered the iberian continent. Its top coincides with a intrasinemurian stratigraphic discontinuity surface which was formed as a consequence of a first phase of rifting and of sea level fall. Because of this event the studied area became a bahamian-type isolated bank where the sequence J.2 was deposited. This bank was separated from the pericontinental platform situated to the North by a seaway where hemipelagic facies were deposited. The top of the Gavilan Fm. coincides with a stratigraphic discontinuity surface of Carixian age, which was related with a second and more important rifting phase, also connected with a sea level fall. This event caused the paleogeographic differentiation in troughs and swells in the South Iberian Paleomargin. Above this surface only very thin and lacunose, continental to hemipelagic deposits of the Upper Liassic are present: they frequently appears as paleokarst fillings and neptunian dykes. Finally, after a third discontinuity surface, a new shallow water carbonate bank with predominantly oolitic sedimentation was formed at the beginning of the Dogger.