[EN] This Ph.D. thesis, entitled “Sedimentology and paleogeography of the coastal wetland systems of the Leza Fm (Early Cretaceous, Cameros Basin): Implications on the origin and development of associated microbial deposits”, presents the results of the first detailed and thorough study of the Leza Formation (Leza Fm), a mainly carbonate unit (but also including clastic deposits and originally evaporitic deposits, currently preserved as pseudomorphs), which crops out in the region of La Rioja, Northern Spain. The Leza Fm was deposited in the tectonically-active northern margin of the Cameros Basin, a Late Jurassic- Early Cretaceous intraplate extensional basin of the Iberian tectonic plate. No previous works have focused on the Leza Fm as a whole, but many previous authors who studied the geology of the Cameros Basin have mentioned its deposits, and some of them have made interpretations of partial aspects of the unit, especially regarding its age and lateral relationship with other units of the basin, its tectonic context, and its sedimentological origin. Thus, the Leza Fm is a challenging unit with uncertain stratigraphy and age, due to the scarcity of chronostratigraphic markers, and with uncertain sedimentology, due to the occurrence of fossils of both continental and marine affinities. In addition, during the development of this research, an unusual diversity and abundance of microbialites has been discovered in the Leza Fm deposits, adding further complexity to the study of the system.

[ES] El objetivo principal de esta tesis doctoral es proponer una reconstrucción paleoambiental y paleogeográfica general de todo el registro de la Fm Leza, realizada a partir de interpretaciones estratigráficas, sedimentológicas, paleontológicas, tectónicas, y relativas a las microbialitas. Una reconstrucción que, a su vez, se integre dentro de contextos mayores, tanto a escala de la Cuenca de Cameros como de la Placa Ibérica.

MICINN/CGL2011-22709

MICINN/CGL2008-01648

Peer reviewed