El tránsito compresión-extensión en las cuencas cenozoicas de la Cordillera Ibérica oriental: registro mediante lineaciones de disolución en el norte de la Cuenca de Teruel

Zusammenfassung

The transition period between the development of Palaeogene, syn-orogenic basins and Neogene extensional basins in the Iberian Chain involves a change in tectonic regime that is barely recorded in Cenozoic materials. At the northern end of the Teruel Basin, the timing and the character of that tectonic change have been analysed by surveying solution lineations in conglomerate pebbles. The distribution of such lineations along a continuous stratigraphic succession (which includes a remarkable progressive unconformity) shows how compressional stress systems (horizontal σ1 ) are only recorded in its lower part, while extensional ones (vertical σ1 ) are recorded in its upper part. This upper part partially correlates with the units defined and dated in the Teruel Basin (Vallesian-Ruscinian). The lower part is attributed to the middle-upper Aragonian, younger than (or slightly overlapped with) the final sedimentary infill of the neighbouring Aliaga Basin, which only records compressional stress systems. As a result, the transition between both stress regimes should have occurred during the early Vallesian (ca. 10-11 Ma). As in other zones of the Iberian Chain, that transition was gradual in our study area and did not involve any significant tectonic inversion at a macrostructural scale.