Resumen: Weald Facies from the Iberian Lower Cretaceous are represented by several formations like Camarillas Fm, Galve Fm, Cantaperdius Fm and others. In the case of Mirambel Formation, most of the studies were carried out in the 20th century being the recent ones mainly focused on vertebrate findings. Mas de Clapises I site (Portell de Morella, Castellon, Spain) has a high amount of dinosaur and other vertebrate findings out of geological context due to the lack of previous studies. In order to identify to which formation Mas de Clapises I belongs, a multidisciplinary study was carried out (stratigraphy, mineralogy and micropaleontology). According to the results obtained, Mas de Clapises I was a barrier island system in the Mirambel Formation (in the lowermost part of the Lower Barremian attributed by charophyte associations and stratigraphical correlation) that suffered a transgressive event. Lagoon/lacustrine environments with charophytes (Atopochara trivolvis var. triquetra, Favargerella aquavivae, etc.), ostracodes (Cypridea) and also washover fans, tidal flats and emersion events with development of lateritic soils, evolved progressively to coastal facies (foreshore and shoreface) and final offshore facies with Chondrichthyes (Hybodus indet.), Osteichthyes (Pycnodontiformes and Amiidae), crocodylomorphs (Bernissatiidae), and benthic agglutinated foraminifera (Choffatella and Pseudocyclammina). The stratigraphic section ends at the beginning of a thick carbonate deposit that outcrops extensively in the area from the Artoles Formation (Upper Barremian).