The gravity field in the Ne zone of the Madrid Basin and conterminous areas is characterised by a number of regionally important anomalies referred to gradients and minimum and maximum axes. The Ledanca gradient separates two domains. Northwest of it, the hercynian basement structures are overprinted by the southern Central Systemalpine thrusts, which trend NE-SW. The Alcobendas minimum is largely attributable to the thicker sedimentary in fill of the Tertiary Basin.S outheast of it, the gradient on Altomira Front bounds the Madrid Basin, N-S maximum axes reflect Altomira striking structures. To the east of the Villanueva de Alcorón gradient a maximum related to an alpine basement uplift and a minimum where the cover is thicker. The Ledanca gradient is due to a fault that deflects in a dextral sense the basement structures