The emplacement mechanism of the Nahuelbuta pluton (Chile, 37°00? - 38°15? s) based on the anisotropy of the magnetic susceptibility and microstructures

STEENKEN, A.; RABBIA, O.; LÓPEZ DE LUCHI, M. G.; VELOSO, E

Latinmag Letters

Instituto de Geofísica Universidad Autónoma de Méjico

Lugar: DF Mejico; Año: 2013 vol. 3 p. 1 - 3

0016-8033

The anisotropy of the magnetic susceptibility (AMS) in the low magnetic field under laboratory conditions was determined for the Nahuelbuta Pluton, which is part of the Coastal Batholith (Southern Chile)and intruded the Eastern Series of the basement of the Coastal Cordillera. From the bulk value for the magnetic susceptibility it is indicated that all the igneous rocks are dia- and paramagnetic. The foliations have N-S strike. The inclination of the foliation is vertical at the borders to moderately inclined in the centre of the pluton. The lineation is subhorizontal. The shape of the anisotropy is oblate and the corrected degree of anisotropy is less than 1.052. A suggested model for the fabrics is an N-S oriented fault in a compressive tectonic setting that was responsible for the pluton emplacement. But this still has to be confirmed by additional AMS data and the structures of the rocks.