Andráš, P.

Chovan, Martin

Král, J.

Neiva, A. M. R.

Schroll, E.

Zachariáš, J.

English

Andráš P.

Chovan Martin

Schroll E.

Neiva A. M. R.

Král J.

Zachariáš J.

University of Szeged

Acta Mirieralogica-Petrographica, Abstract Series 1, Szeged, 2003 WESTERN CARPATHIAN AND SELECTED EUROPEAN Sb-MINERALIZATIONS; Pb -ISOTOPE STUDY ANDRÁS. P. ' , CHOVAN, M.2, SCHROLL, E.3, NEIVA, A. M. R.4, KRÁL, J.5 & ZACHARIÁS, J.6 ' Geological Institute, Slovak Academy of Sciences, Severná 5, SK-974 01 Banská Bystrica, Slovak Republic. E-mail: andras@savbb.sk 2 Deparment of Mineralogy and Petrology, Comenius University, Mlynská dolina G, SK-842 15 Bratislava, Slovak Republic. 3 Institute of Mineralogy and Crystallography, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria. 4 Departamento de Ciencias da Terra, Universidade de Coimbra, P-3000 Coimbra, Portugal. 5 Slovak Geological Office - Geological Survey of Slovak Republic, Mlynská dolina 1, SK-817 04 Bratislava, Slovak Rep. 6 Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, CZ-128 43 Praha 2, Czech Republic. The Pb-isotope study of Sb-mineralizations from the Western Carpathians show a polycyclic character of the ore forming process. Tatric Unit - the oldest model ages (corresponding to uranogenic lead) were determined in samples from the Nizke Tatry Mts (about 400 Ma). The second group of the data from this region vary between 300-330 Ma and the third one about 200 Ma (ANDRÁS et al„ 1998). The main field of the results from the Male Karpaty Mts. is clustered round time-linea at 200-250 Ma (Pezinok deposit). The second group of the model ages is about 110-120 Ma (Pezinok and Pernek deposits). Kriváft occurrence (Vysoké Tatry Mts.) belongs to the last group (155-160 Ma). The Sb-mineralization from the Helcmanovce, Poproő and Grexa deposits (Gemeric Unit) is connected with some younger events (110-140 Ma), includ-ing Permian volcanism. The special position (negative model age) have the samples from Zlatá Bana neovolcanic deposit. The source of the lead from Sb-deposits of the Western Car-pathians is not homogeneous and could be connected with the wall rocks. The lead is derived from crustal rocks, or related material. Eastern Alps. The model ages calculated from the lead isotopes of stibnite from Schlaining (Penninic Rechnitz Win-dow) deposit correspond with the young Alpidic age. The model ages of the other mineralizations can be interpreted as pre-Alpidic. The oldest model ages give stibnite from Drau range: Obertilliach (440 Ma), Radlbergalm (up to 385 Ma) and Rabant (360 Ma). The most important part of the results indicate model ages around 250 Ma. Data from Guginock (Drau range) and Briickl (Gurktal thrust system) indicate influences of younger events and ore-mobilization processes. The large spread of the data is partly due to the presence of r̂v/ OOft young upper crustal Pb enriched in ""Pb and zu"Pb in Varis-can vein type deposits, partly also due to the addition of radiogenic Pb during remobilization of ores under metamor-phic conditions of the Alpine orogenic process. The lead isotope data show the importance of the fluid mixing in the origin of the veins and suggest that the lead was leached from the wall rocks (ANDRÁS et al., 1998). The Pb model ages for the Sb-mineralizations of the Bo-hemian Massif coincide by and large with the assumed time of ore formation during Variscan orogeny. The oldest model ages determined from Krásna Hora deposit (510-435 Ma). Pb-isotope data from Hynőice deposit correspond with De-vonian age - 380 Ma and the sample from PFibram with Carboniferous (or Lower Permian?) age - 295 Ma. With the exception of the data from Krásna Hora deposit the samples indicate average crust origin of lead (n, < 9.80). The oldest 206Pb/204Pb model ages both from Dúrico -Beiräo district and from Trás-os-Montés (Galicia-Trás-os-Montés zone, Northern Portugal) correspond with Devo-nian age. They range from 405 (Alto do Subrido, Dúrico -Beiräo district and Coitadinha-Grijó, Trás-os-Montés) up to 320 Ma (Alto do Subrido and Medas, Dúrico - Beiräo dis-trict). The majority of the data is concentrated to the field bordered by values from 390 to 320 Ma (Alto do Subrido, Aguiar de Sousa-Abelheira, Moinho do Picäo, Dúrico -Beiräo district). Two samples: from Pinheirinhos and from Borralhal (both from Dúrico - Beiräo district) show some younger mineralization formation about 245 Ma. One an-other sample from Borralhal gives model age at about 120 Ma (Cretaceous?) which represent the result of partial remobilization of the original mineralization . The Pb in stibnite mineralizations is derived from ho-mogenous crustal source. The lead gives | i | values between 9.66 and 10.04 which is higher than the average crust value (9.74). Only the Hi values from 2 samples (from Grip and from Medas) are close to the upper crustal lead (|i, > 10). In the Durico-Beiräo district were the metals mobilized from metamorphic complexes during the regional metamorphosis and during the intrusion of granitoides (304-280 Ma). Data from Northern Portugal and from Bohemian Massif (in contradiction to Western Carpathian and Eastern Alpine area) present the features of the old Variscan terrains without significant younger Alpine overprint. Reference ANDRÁS, P., CHOVAN, M. & SCHROLL, E. (1998). Car-pathian - Balkan Geological Association XVI Congress (Vienna), 4. 4 

Western Carpathian and selected European Sb-mineralizations : Pb-isotope study

http://acta.bibl.u-szeged.hu/31305/1/mineralogica_as_001_004.pdf

Western Carpathian and selected European Sb-mineralizations : Pb-isotope study

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