STRAIN ANALYSIS AND INTEGRATION: QUANTIFYING THE DEFORMATION OF THE LAGHETTI AREA, MAGGIA
NAPPE, SWITZERLAND

Kat Compton

Whitman College, Walla Walla WA 99362

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Fieldwork conducted in the Laghetti Area, a 2300 square meter field area, located approximately 1 km ESE of Lago del Naret and 500 m NNW of the Laghetti summit in the Maggia nappe of the northern Lepontine Alps aimed to test the validity of various strain analysis methods at varying scales and to gain a better understanding of the deformation expressed within the crystalline nappes of the Pennine Zone. Deformation in the Laghetti and surrounding areas exhibits conjugate sets of ductile shear zones and a penetrative lineation within the wallrock. Slip vector calculations, biotite clot RfΦ, and biotite LPO indicate X/Y strain ratios ranging from 1-7 and Y/Z ratios ranging from 1-8. Integration of the data from all three methods indicates deformation is nearly pure plane strain and the principle axes of the calculated strain ellipsoid indicate maximum shortening in the NNW-SSE direction, strengthening the claim that deformation in the Laghetti area is a result of the Alpine orogeny.