STRUCTURAL MODEL OF THE PANAMA - NORTH ANDES PLATE BOUNDARY ZONE FROM REMOTE SENSING, GEOLOGIC MAPPING AND SEISMIC TOMOGRAPHY

To advance in the understanding of the tectonic setting of the Panama - North Andres plate boundary zone, an integrated research project is being carried out, including remote sensing, field geology, gravity and magnetic surveys and passive seismic tomography. This program includes the geologic interpretation of C band -RADARSAT, X-band TERRASAR and L-band ALOS PALSAR images with fieldwork verification. The Panama microplate is characterized by intrusive and extrusive igneous rocks or cretaceous and tertiary ages, respectively, while the North Andes is formed by a thick sedimentary sequence of tertiary age. Thick quaternary deposits of the Atrato river and the Gulf of Uraba are covering the plate boundary zone. A seismological network with 25 triaxial broadband stations has been implemented to monitor the seismic activity since January 2009 to present. The registered seismic events have been processed including the determination of first arrival of P and S waves and their wave attenuation, Regional stress and strain estimates and seismic anisotropy are being calculated. Three structural trends are identified: a) NE structures associated with main regional faults b) EW and NE structures associated with secondary regional faults and c) local structures and lineaments associated with major fractures. Mud volcanoes were detected in the northeastern part of the basin. Some of them aligned with NW and EW structures.