Magmatic-tectonic jointing in, granitoids of the Tatra Mts

Abstract

Granitoid massif of the Tatra Mts, regarded as a part of the Variscan pluton, has little been known in its structural respect. A broad extent of quartz-felspar-biotite foliation, produced under the pressure of magma in late-magmatic or pegmatitic stage is recognized. In the -central part of the investigated area of the High Tatra Mts it is horizontal or subhorizontal, but at the margin it is NW inclined; the attitude of joints is changing respectively. Together with the presence of aptite and pegmatite fillings it proves a role of prototectonic (late-magmatic) factors in foundation of joint net. Indications are also present for postintrusive, Variscan compression. All these features can be explained if we assume a unique field of residual stresses resulting from superposition of prototectonic and tectonic stress fields. Systematic fractures produced in such a way are named here the magmatic-tectonic jointing. The proposed approach removes a: number of contradictions in interpretations of jointing in some plutonic massifs and reduces criticism against the old concept of Granittektonik introduced by Hans CLOOS.