Contribuition from potential field methods to regional tectonic studies of the Western Iberian Continental Margin

Abstract

This paper aims to illustrate how potential field methods, such as gravimetry and magnetometry, could be helpful to understand the regional tectonic framework of the Western Iberia Continental Margin. The proposed data handling results in a revised interpretation of the main tectonic domains. The data base included public sattelite gravity data and the EMAG2 Project magnetic data. Based on different geophysical signatures, three crustal domains were identified in this area: continental, transicional and oceanic crust. 
Observations from gravity data are able to point out the probable continental crust boundary. Furthermore, gravity data reveal additional tectonic edges unveiled by the enhancement of the Bouguer anomaly grids through the use of some spatial derivatives. These possible interfaces fit well the onshore mapped limits of the main tectonic units that compound the Western Iberian Continental Margin basement. Also, significant basement changes were suggested through the tran-sitional zone by high-frequency and high-amplitude magnetic anomalies westward from J Anomaly.