Magnetometric survey of the Navarino Island plutons (Beagle Channel, Chile).

PERONI J. I.; TASSONE, A.; LIPPAI, H. F.; VILAS, J. F.

Buenos Aires

Workshop; Giambiaggi School- Applied and Enviromental Geophysics; 2012

FCEyN. Dpto. Física.

The Canal Beagle Plutonic Group (BCPG) is a complex of granitoids exposed along the margins of the Beagle channel, in the Gordon, Londonderry, Hoste and Navarino islands. The BCPG belongs to the Fuegian Batholith, the southernmost segment of the three that compose the Patagonian Batholith. In the the southern sector of the channel, in the Navarino island, larger plutonic bodies outcrop. The upper Cretaceous, Castores and Santa Rosa plutons hosted in the Yahgán Formation are mainly composed of tonalite/granodiorite facies, with common dismembered melanocratic synplutonic dykes. A geophysical survey was conducted in order to determine the geometry in depth of the Castores and Santa Rosa plutons. Magnetic measurements were acquired with two magnetometer (EG&G Geometrics and a Scintrex Envi Grad). From these data was performed 2D geophysical model, combining magnetic data, topography and magnetic susceptibility values ​​obtained from samples of the plutons.