Seismological evidence on the geometry of the Orogenic System in central-northern Ecuador (South America)

B. Guillier (1) , J. -L. Chatelain (2, 1) , É. Jaillard (2) , H. Yepes , G. Poupinet (2) , J. -F. Fels (3)

1 IRD - Institut de Recherche pour le Développement
2 UGA - Université Grenoble Alpes
3 UMS 831 - Services communs OMP

Analysis of the spatial distribution of seismicity beneath central Ecuador from a temporary network gives new insights on two main points of the Ecuadorian tectonics. Major structures in the Ecuadorian Andes are East-dipping Late Jurassic to Paleogene sutures reactivated by present-day compression. The oceanic plate is plunging continuously down to a depth of about 200 km with a dip of 25°-35°. We also show that the coastal plain acts as a buttress transmitting stresses to the Andes, beneath which deformation is concentrated.

Mots clés: Structural Geology: Local crustal structure; Tectonophysics: Dynamics; seismotectonics; Information Related to Geographic Region: South America

Domaines: Planète et Univers [physics]

B. Guillier, J. -L. Chatelain, É. Jaillard, H. Yepes, G. Poupinet, et al.. Seismological evidence on the geometry of the Orogenic System in central-northern Ecuador (South America). Geophysical Research Letters, 2001, 28, pp.3749-3752. ⟨10.1029/2001GL013257⟩. ⟨insu-03606671⟩