MODELING GEOPHYSICAL DATA IN THE USHUAIA REGION, TIERRA DEL FUEGO, ARGENTINA: RELATIONSHIP BETWEEN INTRUSIVE BODIES AND TECTONICS

Data on the distribution and geologic meaning of two of the main magnetic anomalies registered in Tierra del Fuego island, Argentina, are presented. Poorly exposed intrusive bodies hosted in Mesozoic rocks are recognized within the area of anomalies on the Bahía Ushuaia intrusive along the Beagle Channel shoreline. The areas enclosed within aeromagnetic anomalies are generally covered by forests, therefore the geophysic surveys became the only available tool for deciphering the size, geometry, orientation, etc of the plutonic bodies. A working hypothesis relates the emplacement of the intrusives to local extension zones along major strike-slip structures in the Beagle Channel for the Bahía Ushuaia intrusive.