Vasković, Nada

English

Vasković Nada

Belousova E.

O'reilly S.

Griffin W.

Srecković-Batocanin Danica

Christofides G.

Koroneos Apostolos

University of Szeged

146 Acta Mineralogica-Petrographica, Abstract Series, Szeged, Vol. 7, 2012 Joint 5th Mineral Sciences in the Carpathians Conference and 3rd Central-European Mineralogical Conference 20–21 April, 2012, University of Miskolc, Miskolc, Hungary NEW U–Pb DATING AND Hf-ISOTOPE COMPOSITION OF THE GORNJANE  GRANITOIDS (SOUTH CARPATHIANS, EAST SERBIA)  VASKOVIĆ, N1 Faculty of Mining and Geology, University of Belgrade, Belgrade, Serbia .1*, BELOUSOVA, E.2, O’REILLY, S.Y.2, GRIFFIN, W.L.2, SREĆKOVIĆ-BATOĆANIN, D.1, CHRISTOFIDES, G.3 & KORONEOS, A.3 2 ARC Centre of Excellence for Core to Crust Fluid Systems and GEMOC, Macquarie University, Sydney, Australia 3 Aristotle University of Thessaloniki, Greece * E-mail: nada.vaskovic@rgf.bg.ac.rs  The main feature of the South Carpathian geotec-tonic framework is the Getic and Danubian nappes (generated during the Cretaceous Alpine crustal conver-gence and shortening). Their Neoproterozoic-Paleozoic (Cambrian to Early Carboniferous) basement is intruded by Late Variscan granitoids, mostly of Pennsylvanian to Early Permian age. Within the Getic nappe, these grani-toids define one N-SE alignment (up to 150 km length) that can be traced from Romania (Sichevita-Poniasca) to Eastern Serbia (Brnjica, Neresnica, Gornjane). Although the Romanian granitoids are relatively well-studied (DUCHESNE et al., 2008) the investigation of the East Serbian ones is still in progress (cf. VASKOVIĆ et al., 2004). The present study provides the first U-Pb and Hf iso-tope results obtained on zircons from the main rock types of the Gornjane pluton (GP): porphyritic monzo-granite [MG], fine-grained granite [FG], medium-grained granodiorite [GD] and fine-grained diorite [FD]. The analyzed zircons are zoned and some of them are older inherited zircons. U-Pb and Hf isotope analyses were done in the GEMOC Key Center (Macquarie Uni-versity, Sydney) using LA-ICP-MS (Model HP 4500, Series 300) and a Merchantek EO LUV LA microprobe, attached to a Nu Plasma multi-collector ICP-MS. The U-Pb ages obtained for the MG (307.1 ± 4.5 Ma), FG (307.6 ± 2.5 Ma and 323.3 ± 2.6 Ma), GD (307.1 ± 2.9 Ma) and FD (305.8 ± 3.6 Ma) confirm the em-placement and magmatic crystallization of the GP dur-ing Late Variscan events. The ages of inherited zircons from all rock types confirm the involvement of Neopro-terozoic (701–672 Ma) and Paleozoic material of Cam-brian (502–407 Ma) and Devonian-Early Carboniferous (378–342 Ma) age in the magma genesis. The initial 176Hf/177Hf ratios in zircons from all rock types range from 0.282443 to 0.282690 and lie close to CHUR (Fig. 1). Most of the analyzed zircons show moderately juve-nile Hf-isotope composition (εHf is from +2 to +5), with some negative values (mainly in fine-grained granites, εHf down to -5). The mean crustal model age (which assumes a source with the mean crustal Lu/Hf) is ca 1.1 Ga and a maximum crustal model age is ca 1.5 Ga (Fig. 1). Therefore, the GP magmas can be interpreted as being largely derived by remelting of Neoproterozoic to Mesoproterozoic lower crust.  The ages for the GP fit well the results obtained for the Romanian Sichevita-Poniasca pluton (311 ± 2 Ma; DUCHESNE et al., 2008) as well as the late Variscan granites distributed throughout the Danubian nappe (e.g. San Nikola 311.9 ± 4.1 Ma) and the Balkan terrane (e.g. Petrohan 304.6 ± 4.0 Ma; Smilovene 304.1 ± 5.5 Ma; Hisara 303.5 ± 3.3 Ma; Koprivshtitza 312.0 ± 5.4 Ma; CARRIGAN et al., 2005). If we take into consideration an older phase found in FG (sample NDG5 with 323 ± 2.6 Ma age) we can deduce that these granitic magmas were created within a relatively short time span, proba-bly < 20 Ma. This research was supported by project No 176016 of the Serbian Ministry of Science and ARC Centre of Excellence for Core to Crust Fluid Systems and GE-MOC, Macquarie University, Sydney, Australia.  References CARRIGAN, C.W., MUKASA, S.B., HAYDOUTOV, I. & KOLCHEVA, K. (2005): Lithos, 82: 125–147. DUCHESNE, J.-C., LIÈGEOIS, J.-P., IANCU, V., BERZA, T., MATUKOV, D.I., TATU, M. & SER-GEEV, S.A. (2008): International Journal of Earth Sciences (Geologische Rundschau), 97: 705–723. VASKOVIĆ, N., KORONEOS, A., CHRISTOFIDES, G., SREĆKOVIĆ-BATOĆANIN, D. & MILOVA-NOVIĆ, D. (2004): Bulletin of the Geological So-ciety of Greece, 36: 615–624.      Fig. 1. Hf-isotope data for the Gornjane pluton:  NDG-4 = porphyritic monzogranite, NDG-5 = fine grained granite, NDG-20 = medium grained granodi-orite, NDG-22 = fine grained diorite. 

New U-Pb dating and Hf-isotope composition of the Gornjane granitoids (South Carpathians, East Serbia)

http://acta.bibl.u-szeged.hu/33073/1/mineralogica_as_007_146.pdf

New U-Pb dating and Hf-isotope composition of the Gornjane granitoids (South Carpathians, East Serbia)

Abstract

Similar works

Full text

Available Versions

University of Szeged