Contents
U-Pb ZIRCON AGES OF DIORITIC AND TRONDHJEMITIC ROCKS FROM A LAYERED AMPHIBOLITIC COMPLEX CROSSCUT BY GRANITE VEIN (VEPORIC BASEMENT, WESTERN CARPATHIANS)
Published: Feb 2001
Pages: 49 - 60
Authors: MARIAN PUTIS, ALEXANDER B. KOTOV, SERGEI P. KORIKOVSKY, EKATHERINA B. SALNIKOVA, SONYA Z. YAKOVLEVA, NATALYA G. BEREZHNAYA, VICTOR P. KOVACH, YULIA V. PLOTKINA
Abstract: The complex of Ky-Grt paragneisses, granitic to tonalitic orthogneisses, migmatitic gneisses and homogeneous to layered amphibolites was intruded by dioritic-gabbroic more or less concordant dykes and sills during the syn-metamorphic extension in the host regional metamorphic rocks. They now have the character of dioritic orthogneisses. The whole lithological sequence was then structurally unified during the late-metamorphic cooling and exhumation within the deep-crustal shear zone. The dioritic orthogneisses bear the features of pre-metamorphic compositional layering into cumulate-like hornblendite(±Px), gabbro-diorite, tonalite to trondhjemite. Magmatic layering has been transformed to subsolidus high-temperature layering along the extensional meso-shear bands filled with leucotonalitic melt seggregates crosscutting former magmatic structures at acute to medium angles. A new ductile strain relocalization enhanced mechanical differentiation of dark and felsic minerals into often isoclinally folded layers, with the crystallographic preferred orientation fabrics of amphibole, plagioclase and quartz indicating a layer parallel shear. The U-Pb zircon age of porphyric metadiorites 346±1 Ma (Early Carboniferous) is related to their magmatic emplacement, immediately followed by the high-temperature mylonitization. We also dated zircon of metatrondhjemitic orthogneiss from the layered amphibolite. An upper intercept age 514±24 Ma (Late Cambrian) is interpreted as dating the magmatic compositional differentiation of a gabbro-dioritic complex into cumulate-like hornblenditic, gabbrodioritic, tonalitic to trondhjemitic layers, which is an inherited feature in layered amphibolites (with blastic textures). The lower intercept age 348±31 Ma (Early Carboniferous) obviously reflects the time of regional-metamorphic event and formation of layered amphibolites. The whole composite (VZP-CB) structural complex is crosscut by plagiogranite-aplitic veins dated 233±4 Ma (Early Triassic).
Keywords: Western Carpathians, Veporic basement, layered metamagmatites and amphibolites, U-Pb zircon isotope dating
Download PDF documentVolume 52 no. 1 / February 2001
LESZEK MARYNOWSKI, ALEKSANDRA GAWEDA, STEFAN CEBULAK, MARIUSZ JEDRYSEK
HYDROCARBONS MIGRATION IN TECTONIC ZONES OF THE WESTERN TATRA MOUNTAINS CRYSTALLINE BASEMENT (CENTRAL WESTERN CARPATHIANS)KADOSA BALOGH, PAOLA CASSOLA, MASSIMO POMPILIO, DIEGO PUGLISI
PETROGRAPHIC, GEOCHEMICAL AND RADIOMETRIC DATA ON TERTIARY VOLCANO-ARENITIC BEDS FROM THE SICILIAN MAGHREBIAN CHAIN: VOLCANIC SOURCES AND GEODYNAMIC IMPLICATIONSLILIAN SVABENICKA
LATE CAMPANIAN/LATE MAASTRICHTIAN PENETRATION OF HIGH-LATITUDE CALCAREOUS NANNOFLORA TO THE OUTER WESTERN CARPATHIAN DEPOSITIONAL AREAULRIKE POLLER, PAVEL UHER, MARIAN JANAK, DUSAN PLASIENKA, MILAN KOHUT
LATE CRETACEOUS AGE OF THE ROCHOVCE GRANITE, WESTERN CARPATHIANS, CONSTRAINED BY U-Pb SINGLE-ZIRCON DATING IN COMBINATION WITH CATHODO-LUMINESCENCE IMAGINGMARIAN PUTIS, ALEXANDER B. KOTOV, SERGEI P. KORIKOVSKY, EKATHERINA B. SALNIKOVA, SONYA Z. YAKOVLEVA, NATALYA G. BEREZHNAYA, VICTOR P. KOVACH, YULIA V. PLOTKINA
U-Pb ZIRCON AGES OF DIORITIC AND TRONDHJEMITIC ROCKS FROM A LAYERED AMPHIBOLITIC COMPLEX CROSSCUT BY GRANITE VEIN (VEPORIC BASEMENT, WESTERN CARPATHIANS)