A review of polyphase karstification in extensional tectonic regimes: Jurassic and Cretaceous examples, Betic Cordillera, southern Spain

Five karstification phases are recognized and analysed in the Mesozoic carbonate sequences of the External and Internal Subbetic (Betic Cordilleras, southern Spain). These phases are related to important stratigraphic discontinuities in the following ages: (1) Intra-Carixian, (2) Early–Middle Jurassic boundary, (3) late Bathonian–early Callovian, (4) Intra-Kimmeridgian, and (6) late Albian. The importance of each karstification phase is variable according to the region. Moreover, not all the karstic phases occur in every area, although in some places several phases may be superimposed, appearing as discrete palaeokarst features or overprinting earlier ones. In the case of polyphase karstification each successive karstic process modified earlier features and was also conditioned by them. This interdependence complicates any attempt to isolate the individual karst events. The interpretation of the genetic history of the palaeokarst as a whole, therefore, requires the integration of data from different outcrops, where they need to be particularly well exposed. This is the only way to arrive at an accurate hypothesis. The five described palaeokarst phases are closely related to the rifting evolution of the Southern Iberian palaeomargin. They coincide with episodes of sudden sea-level fall in the External and Internal Subbetic caused by local tectonic events, commonly involving block-tilting related to the movement of listric faults differing in magnitude in each palaeogeographic–palaeotectonic range, and eustatic sea-level changes.  1999 Elsevier Science B.V. All rights reserved.