Triassic-Miocene paleogeography and basin evolution of the Subbetic Zone between Ronda and Malaga, Spain

Abstract

During the Triassic, continental and supratidal environments prevailed in the north of the Ronda-Málaga region whereas intertidal and shallow marine environments characterize the south. From the Jurassic up to the Miocene, the Ronda-Málaga region was the scene of shallow marine environments in the north and open or deeper marine environments in the south. The Miocene reveals rapidly changing paleo-environments. During the Aquitanian a submarine fan system developed with clastic supply from an emerged area in the north. In the Burdigalian, deformation started to the south of the study area and depositional patterns completely reversed, now showing detritus supply from an emerged area in the south. The entire area emerged during Langhian and Serravallian times and several local extension basins developed in the Tortonian. Backstripping analysis reveals four phases of accelerated subsidence related to extension in the Mesozoic: Anisian-Ladinian (241-235Ma), Norian-Hettangian (223-203Ma), Callovian-Tithonian (161-146Ma), and Cenomanian-Turonian (97-89Ma). These phases can be correlated with tectonic events in the Central Atlantic Ocean. The Tertiary subsidence record shows a change from slow to rapid subsidence in the Late Oligocene and Early Miocene related to a change from extensional to compressional tectonics. Throughout the Middle and Late Miocene and the Pliocene, strike-slip tectonics resulted in local extension and compression giving rise to renewed basin development. The paleogeographic reconstructions together with subsidence analysis allow to discuss the tectonostratigraphic evolution of the Ronda-Málaga region within the framework of western Mediterranean plate tectonics.