Computation of the values of the finite strains in the Molare region, Ticino, Switzerland, using stretched tourmaline crystals

Abstract

SummaryThe stretched crystals of tourmaline occur in the Orange Group gneisses of the Lucomagno massif and in the quartzite of Piano Croce Group in the Molare region, Ticino, Switzerland. They were stretched as a result of an extension acting in the plane containing the tourmaline crystals by the tectonic strain of F3 phase of deformation. The crystals show extension parallel to the F3 fold axes. The computation of the values of the finite strain from stretched tourmaline crystals indicates a constriction-type ellipsoid for the tectonic strain of F3 phase of deformation.