A seismic scale cross-section of the Marine Jurassic of the Santander Basin (Lias and Dogger, western part ofthe Basque-Cantabrian Region, north Spain) is reconstructed based on both outcrop and well log data. It demostrates the unequeal sedimentary filling of the tectonically contro/led swells and troughs in which the basin is subdivided. Further application of sequence stratigraphy concepts leads to the distinction of nine depositional sequences. Their respective facies associations are a function of the relationship between absolute sea leve/ and regional tectonics during the developement of the sucessive systems tracts