Resumen: The Santo Domingo Anticline (External Sierras, Southern Pyrenees), which separates the Jaca piggyback basin from the Ebro foreland basin, is a key structure of the Pyrenees. Its geometry has been interpreted both as a detachment fold and as a hangingwall anticline associated with an underlying thrust. In this paper, we present the results from a gravity survey and 2.5D gravity modelling carried out around the Santo Domingo Anticline. Density measurements indicate a sharp density contrast between the Triassic evaporites-mudstones in the core of the anticline and the sedimentary sequence (limestones and sandstones) at its limbs. Gravity anomalies together with 2.5D gravity models allow to discern the along-strike structural changes. From east to west, we document a change from the ramp-associated fold to the detachment anticline. The capabilities and limitations of the gravimetric method for the determination of fold geometry are also discussed. Idioma: Inglés DOI: 10.1002/gj.2884 Año: 2017 Publicado en: GEOLOGICAL JOURNAL 53, 1 (2017), 178-190 ISSN: 0072-1050 Factor impacto JCR: 1.654 (2017) Categ. JCR: GEOSCIENCES, MULTIDISCIPLINARY rank: 110 / 189 = 0.582 (2017) - Q3 - T2 Factor impacto SCIMAGO: 0.846 - Geology (Q2)