Poligeniczna mineralizacja żyłowa w skałach krystalicznych suwalskiego masywu anortozytowego (NE Polska)

Abstract

The polygenetic vein mineralization in the crystalline rocks of the Suwałki anorthosite massif (NE Poland).S u m m a r y. The detailed research studies of selected secondary polyphase carbonate-sulphate mineralisations infilling fissures and fractures has been carried out in the crystalline rocks of the Suwałki Anorthosite Massif (SAM). This massif, emplaced within the Mesoproterozoic rapakivi-type Mazury Complex (ca. 1.56 Ga), has been subjected to several tectono-hydrothermal events resulting in extensive mineralization in several stages. The deformation regime changed from the ductile compressional to brittle extentional. Both ductile and brittle shear zones enabled the mineralisation precipitation in the sequence C1 (dolomite) or C1 (calcite) + chlorite → pseudotachylyte C2 (calcite) → C3 (calcite) + smectite → Qtz1 → C3 (continued) → Brt → Qtz2 → Anh. The results of mineralogical and stable isotope studies indicate that the vein mineralization originated from the mixed hydrothermal to hypergenic fluids with admixture of marine-type sulphate waters during the last stage of mineralization.