The geological structures of the Pyrenees and their peripheral basins examined through EMAG2v2 magnetic data

Abstract

The major goal of this work is to provide insight into the structural and geological anatomy of the Pyrenees based on the magnetic anomalies and inferred lineaments from Earth Magnetic Anomaly Grid 2 arcmin resolution (EMAG2v2) magnetic data. We focus on providing qualitative and semi-quantitative evidence of the magnetic signature of the Pyrenees mountain range domains and structures. The integration of reduced-to-the-pole and processed maps, as well as the Bouguer anomaly map with geological data, has proved to be significantly useful in order to shed light on the main anomaly sources. Considering their magnetic response and texture, several anomalies can be linked to buried geological bodies or changes in the magnetic character of the basement. We have estimated their source bodies' depth through Euler and power spectrum calculations. We have identified and confirmed eight magnetic zones with different features and interpreted them in terms of the geological and structural setting of the area: one on the Aquitaine Basin with the highest magnetic response in the area, linked to the Sub-Pyrenean Thrust; three along the North Pyrenean Zone linked to mantle materials; one to the east of the Axial Zone representing the boundary between the Pyrenean mountain range and the Mediterranean Sea; two more located in the Catalan Coastal Range related to the volcanic fields in the area; and one in the Gulf of Lyon caused by a thicker crustal block. The result is an overall interpretation of the Pyrenees main magnetic domains.