Lithospheric response to volcanic loading by the Canary islands: Constraints from seismic reflection data in their flexural moats, Geophys

We use multichannel seismic reflection profiles to determine the seismic stratigraphy of the flexural moat that flanks the Canary Islands. The moat stratigraphy has been divided into 5 units on the basis of internal character and correlation of distinctive reflections. The deepest units, I and II, which well-ties indicate are Eocene and older, thicken towards the east suggesting they are the consequence of sediment loading at the Moroccan continental margin. Units III, IV and V, which are Oligocene and younger and highly reflective, thicken concentrically around individual islands suggesting they are dominantly the result of volcanic loading. Distinct stratigraphic patterns of onlap at the base and offlap at the top of individual flexural units are seen on the across-moat profiles but they were not easily identified on our limited along-moat profiles. The thickness of the upper three units is in accord with the predictions of flexural loading models. Moreover, a model in which the volcanoes that make up the Canary Islands progressively load the underlying lithosphere from east to west generally accounts for the thickness variations that are observed in the region of individual islands. We date the shield building stage