Journal of the Geological Society , London, Vol. 163, 2006, pp. 487–498. Printed in Great Britain. 487 Extensional fault control on the sedimentation patterns in a continental rift basin: El Castellar Formation, Galve sub-basin, Spain CARLOS L. LIESA 1 , ANA R. SORIA 2 , NIEVES MELE ´ NDEZ 3 & ALFONSO MELE ´ NDEZ 2 1 A ´ rea de Geodina ´mica Interna, Departamento de Ciencias de la Tierra, Universidad de Zaragoza, C/ Pedro Cerbuna, 12, E-50009, Zaragoza, Spain (e-mail: carluis@unizar.es) 2 A ´ rea de Estratigrafı ´a, Departamento de Ciencias de la Tierra, Universidad de Zaragoza, C/ Pedro Cerbuna, 12, E-50009, Zaragoza, Spain 3 Departamento de Estratigrafı ´a, Universidad Complutense, E-28040, Madrid, Spain Abstract: In the Galve sub-basin, the sedimentary record of the Upper Hauterivian–Lower Barremian El Castellar Formation is divided into two stages by a marlstone interval with gypsum. Stage 1 shows a great variety of subenvironments and facies (alluvial, palustrine and lacustrine) whereas in stage 2 an extensive, shallow carbonate lake developed. Sedimentation was controlled by a system of south-dipping, ENE–WSW listric normal faults, laterally bounded by NNW–SSE steeper transfer faults. Faults controlled sedimentation from a basin scale (basin margins and main characteristics and evolution of sediments) to a regional and a local scale (thickness and facies distribution of the synrift series as well as the location and evolution of lakes and minor alluvial fans). The changes between stages 1 and 2 are related to the passing from an independent movement of faults to the movement of all the extensional faults as a whole, at a sole detachment level. The interval with gypsum was caused by underground water flow changes associated with the interrelation and connection of the faults in the transition period. These changes have been correlated with the transition from the rift initial stage to the rift climax stage, which took place in the Hauterivian–Barremian transition. Continental deposits, and especially carbonate lake sediments, are sensitive indicators of both climatic and tectonic processes, because the third variable controlling the sedimentary succession, i.e. global eustasy, can be discarded as a factor driving sedimen- tation and accumulation (De Wet et al. 1998). Otherwise, sedimentation is significantly influenced by the attitude and arrangement of growth faults, although natural examples (e.g. Gawthorpe & Hurst 1993; Busby & Ingersoll 1995; Purser & Bosence 1998; Einsele 2000; Gawthorpe & Leeder 2000) and sand-box experiments (McClay & Ellis 1987a, b; McClay & Scott 1991) have commonly focused on single fault models. Thus, thickness and facies spatial changes of sedimentary units have been explained by extensional tectonics associated with domino (e.g. Jackson & McKenzie 1983; Buck 1988; Corte ´s et al. 1999; Fridrich 1999) and listric (Wernicke & Burchfield 1982; Gibbs 1984; Jackson 1987; Groshong 1989; Schlische 1991; Bosence 1998; De Wet et al. 1998; Leeder et al. 2002) growth fault systems. Significant lateral and vertical changes of facies and thickness in lacustrine and alluvial systems have been related to the activity of border faults and syndepositional, intra- basinal faults or release faults (e.g. Destro 1995; Blair & Reynolds 1999; Corte ´s et al. 1999). Few studies have dealt with the control by complex structural models on the sedimentary record and its evolution (e.g. Gibbs 1990; Gawthorpe & Leeder 2000). This paper describes detailed relationships, on different scales, between tectonics and sedimentary evolution in a continental (alluvial and lacustrine) basin controlled by a complex exten- sional fault pattern. This study focuses on the Early Cretaceous El Castellar Formation of the Galve sub-basin (eastern Spain, Fig. 1), a marginal basin of the Early Cretaceous Maestrazgo Basin located in the eastern Iberian Basin (Fig. 2a). Outcrops of pre-, syn- and post-rift strata and extensional faulting are well exposed because of recent climatic (arid) conditions, the Tertiary compressive structure, and later considerable peripheral uplift. These circumstances allow the 3D analysis of sediments and faults. The results presented here are based not only on a detailed outcrop and aerial photograph analysis, but also on the study and correlation of seven stratigraphic sections across the Galve sub- basin. Geological setting The Early Cretaceous Galve sub-basin was a small marginal basin that formed part of the larger Maestrazgo (Maestrat) Basin. It is located in the eastern part of the Iberian Chain (Fig. 1). During the Palaeogene, as a result of the Africa–Europe inter- action, the Iberian Chain developed by tectonic inversion of Mesozoic rifts, which correspond to the Iberian Basin (A ´ lvaro et al. 1979; Salas & Casas 1993; Salas et al. 2001; Capote et al. 2002). Mesozoic sedimentation in the Iberian Basin took place within an intraplate extensional tectonic framework (A ´ lvaro et al. 1979; Salas & Casas 1993; Capote et al. 2002) with two main rift stages (Late Permian to Hettangian and Late Jurassic to Early Cretaceous). The rifting process has been related to Tethys and Central Atlantic spreading (Salas & Casas 1993). During the Late Jurassic–Early Cretaceous rifting stage, differential subsi- dence was caused by the reactivation of structural grain (late and post-Variscan or Triassic faults) and the formation of NW–SE and NE–SW normal faults (e.g. A ´ lvaro et al. 1979; Salas & Casas 1993; Salas & Guimera ` 1996; Soria 1997; Mele ´ndez et al. 1998). This process led to the creation of smaller sedimentary basins such as the Galve and other sub-basins (Fig. 2a). Consid- erable evidence of uplift and erosion of local highs, tilting of the pre- and synrift sequence, and angular unconformities related to