Evolución sedimentaria en la zona de enlace Cordillera Ibérica-Sistema Central, margen occidental de la cuenca del Tethys durante el Triásico Medio.

Abstract

The junction between the Iberian Ranges and the Central Syslem was a key region during the Middle Triassic, due to it represented a key area of the westcrn sector of the Tethys basin margin during that time. Tite sedimentary evolution of this period has been reconstructed taking into account the following points: (1) The space and time relationship between tite lithostratigrapitical formations, as well as tite sedimentary environment represented by them. The different magnitude of sedimentary interruptions; two se (2) dimentary cycles are identified: (a) «Buntsandstein sedimentary cycle», represented towards the end by tite «Cercadillo Sandstones and Siltstones>' Formation with typical fluvial facies and divided in two major sequences (Si and 82); (b) oMuschelkalk sedimentary cycle», comprisíng a basal siliciclastic formation («Torete variegated Siltstones and Sandstones») with predominant ephemeral fluvial facies passing upwards to carbonate formations («Tramacastilla Dolostones» and «Royuela Dolostones, Marís and Limestones» with tite characteristic facies associations of a carbonate ramp changing towards the NW witit tite fluvio-delataic facies from tite «Cuesta del Castillo Sandstones and Siltstones» Formation. The boundary between titese two sedimentary cycles is marked by an angular unconformable surface with smooth palaeorelief witere an onlap geometry is displayed. As a function of tite different order of these sedimentary interruptions, severa] minor sequences are distinguisited.