We investigate the relationships between the anisotropy of magnetic susceptibility (AMS), mineral preferred orientation, macroscopic structures, and finite strain in a section of increasing metamorphism in the Helvetic zone of the Central Alps (Switzerland). The Upper Triassic Quartenschiefer Formation, an initially hematite bearing red bed sedimentary rock, can be traced from unmetamorphosed shale to amphibolite-facies schists. The magnetic fabrics of 805 specimens agree well in orientation with the foliation (normal to kmin, kmax≥kint≥kmin are principal susceptibilities) and the mineral stretching lineation (parallel kmax) in all metamorphic grades. The maximum susceptibility axes are in an approximately N-S orientation and were acquired during the Miocene north directed nappe transport. The effects of the tectonic position and the metamorphic grade on the AMS ellipsoid suggests that deformation has a stronger influence on its shape than the metamorphic grade. The identification and quantification of the sources of magnetic susceptibility was done with (1) a model calculation, (2) the high-field/low-field method, and (3) low-temperature heating curves. The AMS of low-grade samples is dominated by the paramagnetic minerals (mainly mica) and the AMS of higher susceptible medium-grade samples by magnetite. The paramagnetic dominated magnetic fabrics correlate well with mica (002) lattice preferred orientations obtained from X ray texture goniometry. A one to one correlation between March ''strains'' and a magnetic parameter Mi= ln(ki/(kmaxkintkmin) 1/3) is predicted by a numerical model and verified empirically. The magnetic fabrics of well characterized samples can thus be used to quantify the degree of mica preferred orientation using relatively simple magnetic anisotropy equipment. ¿ American Geophysical Union 1993