Modelización gravimétrica en el SW de la Península Ibérica.

Abstract

A gravity research has been carried out in the southwestern part of the Iberian Massif to study the contact between the Ossa-Morena (OMZ) and Southportuguese zones (SPZ). The Bouguer anomaly map shows a relative gravity high over the Aracena metamorphic belt (AMB), and a strong gradient from this high to the NNE as the most conspicuous features. A 2 ½ D gravity modelling has been carried out to explain the Bouguer anomalies in the area. Three different interpretations of the same profile have been elaborated. The first model shows a continuous continental crust and the second one a mantle inflexion. None of them provide a good adjust to the data. In the third model presented the gravity high related to the AMB has been fitted in the model with a north-dipping wedge of lithospheric mantle and metabasites (with tholeiitic oceanic affinity) separating two different continental crust appearing to the north (OMZ) and south (SPZ) of this wedge, which was the suture between these two continents. The results of the gravity modelling process demonstrate that this hipothesis does satisfy the observed gravity data.