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Protolith age and provenance of metasedimentary rocks in Variscan allochthon units: U–Pb SHRIMP zircon data from the Orlica–Śnieżnik Dome, West Sudetes

Published online by Cambridge University Press:  02 November 2009

MIROSŁAW JASTRZĘBSKI ,
ANDRZEJ ŻELAŹNIEWICZ ,
IZABELLA NOWAK ,
MENTOR MURTEZI  and
ALEXANDER N. LARIONOV
MIROSŁAW JASTRZĘBSKI*
Affiliation:
Institute of Geological Sciences, Polish Academy of Sciences, Wrocław, Poland
ANDRZEJ ŻELAŹNIEWICZ
Affiliation:
Institute of Geological Sciences, Polish Academy of Sciences, Wrocław, Poland
IZABELLA NOWAK
Affiliation:
Institute of Geological Sciences, Polish Academy of Sciences, Wrocław, Poland
MENTOR MURTEZI
Affiliation:
Institute of Geological Sciences, Polish Academy of Sciences, Wrocław, Poland
ALEXANDER N. LARIONOV
Affiliation:
Centre of Isotopic Research, All-Russian Geological Research Institute, St Petersburg, Russia
*
†Author for correspondence: mjast@interia.pl
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Abstract

New U–Pb sensitive high-mass resolution ion microprobe (SHRIMP) data from detrital zircons within the Orlica–Śnieżnik Dome provide new insights into the stratigraphic and palaeogeographic position of assumed relict Precambrian basement preserved in the Variscan collisional orogen of the West Sudetes, SW Poland. Hitherto, the Młynowiec Formation and the Stronie Formation within the Orlica–Śnieżnik Dome were assumed to represent two metavolcano-sedimentary successions of Proterozoic and early Palaeozoic age, respectively. However, when previous U–Pb data and mapping data from the Orlica–Śnieżnik Dome are combined with the new detrital zircon isotopic ages both from paragneisses within the Młynowiec Formation and from light-coloured quartzites and mica schists within the Stronie Formation, the result strongly suggests that the protoliths of these two formations actually form a continuous succession. This continuous succession is herein designated the Młynowiec–Stronie Group. The rocks of this group were deposited during middle Cambrian–early Ordovician times (c. 520–470 Ma), presumably at the northern edge of West Gondwana after the 10–20 Ma period of tectonic quiescence that followed the terminal stage of the Cadomian collisions. Monotonous Młynowiec metagreywackes form the lower part of the succession, and the lithologically diverse schistose Stronie Formation forms its upper part. The change from greywacke (Młynowiec) to volcano-sedimentary (Stronie) facies coincided with the onset of rather short-lived volcanic activity which climaxed around 505–495 Ma and which supplied the volcanogenic components to the Stronie Formation. No ‘Cadomian unconformity’ has been observed in the region. Xenocrystic zircons from the Młynowiec–Stronie Group retain records of Archaean (3.0–2.3 Ga), Palaeoproterozoic (2.1–1.8 Ga) and Neoproterozoic to early Cambrian (660–530 Ma) zircon-forming events. These zircon ages, together with the lack of 1.7–1.2 Ga zircon ages, suggest that the source areas for the metasedimentary rocks may have been the West Africa craton, which therefore differs from the Amazonian affinity of the adjacent Brunovistulia Terrane. Nevertheless, two zircons, c. 1.0 and 1.1 Ga old, respectively, indicate that the Młynowiec–Stronie Group sedimentary basin must have still been within the delivery reach of detritus ultimately derived from the Grenvillian-age belt(s). The detrital components of the supracrustal formations of the Orlica–Śnieżnik Dome were mainly derived from Neoproterozoic zircon-bearing crystalline rocks that were accreted to, and included in, the Cadomian basement in several intrusive pulses that culminated at 660–640 Ma, 620 Ma and 570–530 Ma.

Keywords

U–Pb zircon geochronologydetrital zirconsmetasedimentary successionsOrlica–Śnieżnik DomeBohemian Massif
Type
Original Article
Information
Geological Magazine , Volume 147 , Issue 3 , May 2010 , pp. 416 - 433
Copyright
Copyright © Cambridge University Press 2009

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References

Ansilewski, J. 1966. Petrografia metamorfiku Gór Bialskich. Geologia Sudetica 2, 121–259.Google Scholar
Arenas, R., Martínez Catalán, J. R., Sánchez Martínez, S., Fernández-Suárez, J., Andonaegui, P., Pearce, J. A. & Corfu, F. 2007. The Vila de Cruces Ophiolite: a remnant of the early Rheic ocean in the Variscan suture of Galicia (northwest Iberian Massif). The Journal of Geology 115, 129–48.CrossRefGoogle Scholar
Black, L. P., Kamo, S. L., Allen, C. M., Aleinikoff, J. N., Davis, D. W., Korsch, R. J. & Foudoulis, C. 2003. TEMORA 1: a new zircon standard for Phanerozoic U–Pb geochronology. Chemical Geology 200, 155–70.CrossRefGoogle Scholar
Borkowska, M., Choukroune, P., Hameurt, J. & Martineau, F. 1990. A geochemical investigation of age, significance and structural evolution of the Caledonian–Variscan granite-gneisses of the Śnieżnik metamorphic area (central Sudetes, Poland). Geologia Sudetica 25 (1–2), 1–27.Google Scholar
Buschmann, B., Elicki, O. & Jonas, P. 2006. The Cadomian unconformity in the Saxo-Thuringian Zone, Germany: Palaeogeographic affinities of Ediacaran (terminal Neoproterozoic) and Cambrian strata. Precambrian Research 147, 387–403.CrossRefGoogle Scholar
Don, J. 1964. Góry Złote i Krowiarki jako elementy składowe metamorfiku Śnieżnika. Geologia Sudetica 1, 79–117.Google Scholar
Don, J. & Dowidar, H. 1988. Goszów Quartzites and the problem of the Młynowiec Series (Śnieżnik Metamorphic Massif, Sudetes). Bulletin of the Polish Academy of Sciences, Earth Sciences 36, 239–52.Google Scholar
Don, J., Dumicz, M., Wojciechowska, I. & Żelaźniewicz, A. 1990. Lithology and tectonics of the Orlica–Śnieżnik Dome, Sudetes – Recent State of Knowledge. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 197, 159–88.Google Scholar
Don, J., Skácel, J. & Gotowała, R. 2003. The boundary zone of the East and West Sudetes on the 1:50 000 scale geological map of the Velké Vrbno, Staré Město and Śnieżnik Metamorphic Units. Geologia Sudetica 35, 25–59.Google Scholar
Dörr, W., Finger, F., Linnemann, U. & Zulauf, G. 2004. The Avalonian–Cadomian Belt and related peri-Gondwanan terranes. International Journal of Earth Science 93, 657–8.CrossRefGoogle Scholar
Dörr, W., Zulauf, G., Fiala, J., Franke, W. & Vejnar, Z. 2002. Neoproterozoic to Early Cambrian history of an active plate margin in the Teplá-Barrandian unit – a correlation of U–Pb isotopic dilution-TIMS ages (Bohemia, Czech Republic). Tectonophysics 352, 65–85.CrossRefGoogle Scholar
Dumicz, M. 1979. Tectogenesis of the metamorphosed series of the Kłodzko District: a tentative explanation. Geologia Sudetica 14, 29–46.Google Scholar
Fischer, G. 1936. Der Bau des Glatzer Scheegebirges. Jahrbuch Preussisches Geologisches Landesamt 56, 712–32.Google Scholar
Floyd, P. A., Winchester, J. A., Seston, R., Kryza, R. & Crowley, Q. G. 2000. Review of geochemical variation in Lower Palaeozoic metabasites from the NE Bohemian Massif: intracratonic rifting and plume–ridge interaction. In Orogenic processes: Quantification and Modelling in the Variscan Belt (eds Franke, W., Haak, V., Oncken, O. & Tanner, D.), pp. 155–74. Geological Society of London, Special Publication no. 179.Google Scholar
Franke, W. & Żelaźniewicz, A. 2000. The eastern termination of the Variscides: terrane correlation and kinematic evolution. In Orogenic processes: Quantification and Modelling in the Variscan Belt (eds Franke, W., Haak, V., Oncken, O. & Tanner, D.), pp. 63–86. Geological Society of London, Special Publication no. 179.Google Scholar
Franke, W., Żelaźniewicz, A., Porębski, S. J. & Wajspyrch, B. 1993. Saxothuringian zone in Germany and Poland: differences and common features. Geologische Rundschau 82, 583–99.CrossRefGoogle Scholar
Friedl, G., Finger, F., McNaughton, N. J. & Fletcher, I. R. 2000. Deducing the ancestry of terranes: SHRIMP evidence for South America-derived Gondwana fragments in central Europe. Geology 28, 1035–8.2.0.CO;2>CrossRefGoogle Scholar
Friedl, G., Finger, F., Paquette, J., Quadt, A., McNaughton, N. & Fletcher, I. 2004. Pre-Variscan geological events in the Austrian part of the Bohemian Massif deduced from U–Pb zircon ages. International Journal of Earth Sciences 93, 802–23.CrossRefGoogle Scholar
Grześkowiak, A., Żelaźniewicz, A. & Fanning, M. 2005. Early Palaeozoic syntectonic migmatization preceded Variscan metamorphism in the Orlica–Śnieżnik Dome, Sudetes: U–Pb SHRIMP evidence. Geolines 19, 46–7.Google Scholar
Gunia, T. 1984 a. Mikroskamieniałości z łupków kwarcytowych okolicy Goszowa w masywie Śnieżnika Kłodzkiego (Sudety Środkowe). Geologia Sudetica 18 (2), 47–57.Google Scholar
Gunia, T. 1984 b. Mikroflora z wapieni krystalicznych okolicy Nowego Waliszowa (Krowiarki – Sudety Środkowe). Geologia Sudetica 19 (2), 75–86.Google Scholar
Gunia, T. 1990. Acritarcha i mikroproblematyki z wapieni krystalicznych okolicy Romanowa Górnego (Sudety Środkowe – Krowiarki). Geologia Sudetica 24, 101–37.Google Scholar
Harley, S. L., Kelly, N. & Möller, A. 2007. Zircon behaviour and the thermal histories of mountain chains. Elements 3, 25–30.CrossRefGoogle Scholar
Hegner, E. & Kröner, A. 2000. Review of Nd isotopic data and xenocrystic and detrital zircon ages from the pre-Variscan basement in the eastern Bohemian Massif: speculations on palinspastic reconstructions. In Orogenic processes: Quantification and Modelling in the Variscan Belt (eds Franke, W., Haak, V., Oncken, O. & Tanner, D.), pp. 113–30. Geological Society of London, Special Publication no. 179.Google Scholar
Hoskin, P. W. O. & Schaltegger, U. 2003. The composition of zircon and igneous and metamorphic petrogenesis. In Zircon (eds Hanchar, J. M. & Hoskin, P. W. O.), pp. 27–62. Reviews in Mineralogy and Geochemistry no. 53. Mineralogical Society of America.CrossRefGoogle Scholar
Jastrzębski, M. 2009. A Variscan continental collision of the West Sudetes and the Brunovistulian terrane: a contribution from structural and metamorphic record of the Stronie Formation, the Orlica–Śnieżnik Dome, SW Poland. International Journal of Earth Sciences, DOI 10.1007/s00531-008-0357–5), in press.CrossRefGoogle Scholar
Kemnitz, H. 2007. The Lausitz graywackes, Saxo-Thuringia, Germany – witness to the Cadomian orogeny. In The evolution of Rheic Ocean: from Avalonian–Cadomian active margin to Alleghenian–Variscan collision (eds Linnemann, U., Nance, R. D., Kraft, P. & Zulauf, G.), pp. 97–141. Geological Society of America, Special Paper no. 423.Google Scholar
Koszela, S. 1997. Petrogeneza marmurów z południowo-wschodniej części metamorfiku Śnieżnika. Geologia Sudetica 30, 58–115.Google Scholar
Kröner, A., Jaeckel, P., Hegner, E. & Opletal, M. 2001. Single zircon ages and whole-rock Nd isotopic systematic of early Paleozoic granitoid gneisses from the Czech and Polish Sudetes (Jizerske hory, Karkonosze Mountains and Orlica–Śnieżnik Complex). International Journal of Earth Sciences 90, 304–24.CrossRefGoogle Scholar
Kryza, R., Zalasiewicz, J., Mazur, S., Aleksandrowski, P., Segeev, S. & Larionov, A. 2007. Precambrian crustal contribution to the Variscan accretionary prism of the Kaczawa Mountains (Sudetes, SW Poland): evidence from SHRIMP dating of detrital zircons. International Journal of Earth Sciences 96, 1153–62.CrossRefGoogle Scholar
Lange, U., Bröcker, M., Armstrong, R., Żelaźniewicz, A., Trapp, E. & Mezger, K. 2005. The orthogneisses of the Orlica–Śnieżnik complex (West Sudetes, Poland): geochemical characteristics, the importance of pre-Variscan migmatization and constraints on the cooling history. Journal of the Geological Society, London 162, 973–84.CrossRefGoogle Scholar
Larionov, A. N., Andreichev, V. A. & Gee, D. G. 2004. The Vendian alkaline igneous suite of northern Timan: ion microprobe U–Pb zircon ages of gabbros and syenite. In The Neoproterozoic Timanide Orogen of Eastern Baltica (eds Gee, D. G. & Pease, V. L.), pp. 69–74. Geological Society of London, Memoir no. 30.Google Scholar
Linnemann, U., D'Lemos, R., Drost, K., Jeffries, T. E., Gerdes, A., Romer, R. L., Samson, S. D. & Strachan, R. 2008 a. Cadomian tectonics. In The Geology of Central Europe (Volume 1) – Precambrian and Palaeozoic (ed. McCann, T.), pp. 103–54. London: The Geological Society.CrossRefGoogle Scholar
Linnemann, U., Gehmlich, M., Tichomirowa, M., Buschmann, B., Nasdala, L., Jonas, P., Lützner, H. & Bombach, K. 2000. From Cadomian subduction to early Palaeozoic rifting: the evolution of Saxo-Thuringia at the margin of Gondwana in the light of single zircon geochronology and basin development (central European Variscides, Germany). In Orogenic processes: Quantification and Modelling in the Variscan Belt (eds Franke, W., Haak, V., Oncken, O. & Tanner, D.), pp. 131–53. Geological Society of London, Special Publication no. 179.Google Scholar
Linnemann, U., Gerdes, A., Drost, K. & Buschmann, B. 2007. The continuum between Cadomian Orogenesis and opening of the Rheic Ocean: constraints from LA-ICP-MS U–Pb zircon dating and analysis of plate-tectonic setting (Saxo-Thuringian Zone, NE Bohemian Massif, Germany). In The evolution of Rheic Ocean: from Avalonian–Cadomian active margin to Alleghenian–Variscan collision (eds Linnemann, U., Nance, R. D., Kraft, P. & Zulauf, G.), pp. 61–96. Geological Society of America, Special Paper no. 423.CrossRefGoogle Scholar
Linnemann, U., McNaughton, N. J., Romer, R. L., Gehmlich, M., Drost, K. & Tonk, C. 2004. West African provenance for Saxo-Thuringia (Bohemian Massif): Did Armorica ever leave pre-Pangean Gondwana? International Journal of Earth Sciences 93, 683–705.CrossRefGoogle Scholar
Linnemann, U., Pereira, F., Jeffries, T. E., Drost, K. & Gerdes, A. 2008 b. The Cadomian Orogeny and the opening of the Rheic Ocean: The diachrony of geotectonic processes constrained by LA-ICP-MS U–Pb zircon dating (Ossa-Morena and Saxo-Thuringian Zones, Iberian and Bohemian Massifs). Tectonophysics 461, 21–43.CrossRefGoogle Scholar
Ludwig, K. R. 2005 a. SQUID 1.12 A User's Manual. A Geochronological Toolkit for Microsoft Excel. Berkeley Geochronology Center Special Publication, 22 pp. http://www.bgc.org/isoplot_etc/software.htmlGoogle Scholar
Ludwig, K. R. 2005 b. User's Manual for ISOPLOT/Ex 3.22. A Geochronological Toolkit for Microsoft Excel. Berkeley Geochronology Center Special Publication, 71 pp. http://www.bgc.org/isoplot_etc/software.htmlGoogle Scholar
Matte, P., Maluski, H., Rajlich, P. & Franke, W. 1990. Terrane boundaries in the Bohemian Massif: Result of large-scale Variscan shearing. Tectonophysics 177, 151–70.CrossRefGoogle Scholar
Mazur, S., Aleksandrowski, P., Kryza, R. & Oberc-Dziedzic, T. 2006. The Variscan Orogen in Poland. Geological Quarterly 50 (1), 89–118.Google Scholar
Murtezi, M. 2006. The acid metavolcanic rocks of the Orlica–Śnieżnik Dome: their origin and tectono-metamorphic evolution. Geologia Sudetica 38, 1–38.Google Scholar
Murtezi, M. & Fanning, M. 2005. Petrogenesis, Age and Tectono-Metamorphic Evolution of the Acid Metavolcanites of the Stronie Formation (Orlica-Śnieżnik Dome, Sudetes, SW Poland). Geolines 19, 85.Google Scholar
Nance, R. D. & Murphy, J. B. 1994. Contrasting basement isotopic signatures and the palinspastic restoration of peripheral orogens: Example from the Neoproterozoic Avalonian–Cadomian belt. Geology 22, 617–20.2.3.CO;2>CrossRefGoogle Scholar
Nance, R. D., Murphy, J. B., Strachan, R. A., Keppie, J. D., Gutierrez-Alonso, G., Fernandez-Suarez, J., Quesada, C., Linnemann, U., D'lemos, R. & Pisarevsky, S. A. 2008. Neoproterozoic–early Palaeozoic tectonostratigraphy and palaeogeography of the peri-Gondwanan terranes: Amazonian v. West African connections. In The boundaries of the West African Craton (eds Ennih, N. & Liégeois, J.-P.), pp. 345–83. Geological Society of London, Special Publication no. 297.Google Scholar
Oberc, J. 1968. Archaik i Proterozoik. Sudety. In Budowa geologiczna Polski T. 1. Stratygrafia. Część 1 (eds Sokołowski, S., Cieśliński, S. & Czermiński, J.), pp. 63–110. Wydawnictwa Geologiczne. Warszawa.Google Scholar
Oberc-Dziedzic, T., Klimas, K., Kryza, R. & Fanning, C. M. 2003. SHRIMP zircon geochronology of the Strzelin gneiss, SW Poland: evidence for a Neoproterozoic thermal event in the Fore-Sudetic Block, Central European Variscides. International Journal of Earth Sciences 92, 701–11.CrossRefGoogle Scholar
Pin, C. & Waldhausrová, J. 2007. Sm–Nd isotope and trace element study of Late Proterozoic metabasalts (“spilites”) from the Central Barrandian domain (Bohemian Massif, Czech Republic). In The evolution of Rheic Ocean: from Avalonian–Cadomian active margin to Alleghenian–Variscan collision (eds Linnemann, U., Nance, R. D., Kraft, P. & Zulauf, G.), pp. 231–47. Geological Society of America, Special Paper no. 423.Google Scholar
Přikryl, R., Schulmann, K. & Melka, R. 1996. Perpendicular fabrics in the Orlické hory orthogneisses (western part of the Orlice-Sněžník Dome, Bohemian Massif) due to high temperature E–W deformational event and late lower temperature N–S overprint. Journal of the Czech Geological Society 41, 156–66.Google Scholar
Pupin, J. P. 1980. Zircon and granite petrology. Contribution to Mineralogy and Petrology 73, 207–20.CrossRefGoogle Scholar
Sawicki, L. 1995. Geological Map of Lower Silesia with adjacent Czech and German Territories 1:100 000. Państwowy Instytut Geologiczny. Warszawa.Google Scholar
Smulikowski, K. 1979. Ewolucja polimetamorficzna krystaliniku Śnieżnika Kłodzkiego i Gór Złotych w Sudetach. Geologia Sudetica 14 (1), 7–76.Google Scholar
Stacey, J. S. & Kramers, J. D. 1975. Approximation of terrestrial lead isotope evolution by a two-stage model. Earth and Planetary Science Letters 26, 207–21.CrossRefGoogle Scholar
Steiger, R. H. & Jäger, E. 1977. Subcommission on geochronology: convention on the use of decay constants in geo- and cosmochronology. Earth and Planetary Science Letters 36, 359–62.CrossRefGoogle Scholar
Tait, J. A., Bachtadse, V., Franke, W. & Soffel, H. C. 1997. Geodynamic evolution of the European Variscan fold belt: palaeomagnetic and geological constraints. Geologische Rundschau 86, 585–98.CrossRefGoogle Scholar
Tassinari, C. C. G. & Macambira, M. J. B. 1999. Geochronological Provinces of the Amazonian Craton. Episodes 22 (3), 174–82.CrossRefGoogle Scholar
Teipel, U., Eichhorn, R., Loth, G., Rohrmüller, J., Höll, R. & Kennedy, A. 2004. U–Pb SHRIMP and Nd isotopic data from the western Bohemian Massif (Bayerischer Wald, Germany): Implications for Upper Vendian and Lower Ordovician magmatism. International Journal of Earth Sciences 93, 782–801.CrossRefGoogle Scholar
Turniak, K., Mazur, S. & Wysoczański, R. 2000. SHRIMP zircon geochronology and geochemistry of the Orlica–Śnieżnik gneisses (Variscan belt of Central Europe) and their tectonic implications. Geodinamica Acta 13, 393–12.CrossRefGoogle Scholar
Ugidos, J. M., Valladares, M. I., Recio, C., Rogers, G., Fallick, A. E. & Stephens, W. E. 1997. Provenance of Upper Precambrian – Lower Cambrian shales in the Central Iberian Zone, Spain: evidence from a chemical and isotopic study. Chemical Geology 136, 55–70.CrossRefGoogle Scholar
van Breemen, O., Aftalion, M., Bowes, D. R., Dudek, A., Mísař, Z., Povondra, P. & Vrána, S. 1982. Geochronological studies of the Bohemian Massif, Czechoslovakia, and their significance in the evolution of Central Europe. Transactions of the Royal Society of Edinburgh, Earth Sciences 73, 89–108.CrossRefGoogle Scholar
Vangerow, E. F. 1943. Das Normalprofil des Algonkiums und Kambrimus in den mittleren Sudeten. Geologische Rundschau 34, 10–12.CrossRefGoogle Scholar
von Raumer, J. F. & Stampfli, G. M. 2008. The birth of the Rheic Ocean — Early Palaeozoic subsidence patterns and subsequent tectonic plate scenarios. Tectonophysics 461, 9–20.CrossRefGoogle Scholar
von Raumer, J. F., Stampfli, G. M. & Bussy, F. 2003. Gondwana-derived microcontinents — the constituents of the Variscan and Alpine collisional orogens. Tectonophysics 365, 7–22.CrossRefGoogle Scholar
Williams, I. S. 1998. U–Th–Pb geochronology by ion microprobe. In Applications in microanalytical techniques to understanding mineralizing processes (eds McKibben, M. A., Shanks III, W. C. & Ridley, W. I.), pp. 1–35. Reviews in Economic Geology 7.Google Scholar
Wojciechowska, I. 1975. Tektonika kłodzko-złotostockiego masywu granitoidowego i jego osłony w świetle badań mezostrukturalnych. Geologia Sudetica 10 (2), 61–121.Google Scholar
Wojciechowska, I., Ziółkowska-Kozdrój, M. & Gunia, P. 2001. Petrography and geochemistry of leptites from the Skrzynka Dislocation Zone (Eastern Sudetes, SW Poland) – preliminary results. Bulletin of the Polish Academy of Sciences, Earth Sciences 49, 1–11.Google Scholar
Zeh, A., Brätz, H., Millar, I. L. & Williams, I. S. 2001. A combined zircon SHRIMP and Sm–Nd isotope study of high-grade paragneisses from the Mid-German Crystalline Rise: evidence for northern Gondwana and Grenvillian provenance. Journal of the Geological Society, London 158, 983–94.CrossRefGoogle Scholar
Żelaźniewicz, A., Buła, Z., Fanning, M., Seghedi, A. & Żaba, J. 2009. More evidence on Neoproterozoic terranes in Southern Poland and southeastern Romania. Geological Quarterly 53 (1), 93–124.Google Scholar
Żelaźniewicz, A. & Larionov, A. 2008. The Cambrian contractional event in the West Sudetes: Structural and isotopic evidence from Zabřeh Group. Proceedings and Excursion Guide of the 6th Meeting of the Central European Tectonic Studies Group, 154–5.Google Scholar
Żelaźniewicz, A., Mazur, S. & Szczepański, J. 2002. The Lądek-Snieżnik Metamorphic Unit – Recent State of Knowledge. Geolines 14, 115–25.Google Scholar
Zelaźniewicz, A., Nowak, I., Bachliński, R., Larionov, A. N. & Sergeev, S. A. 2005. Cadomian versus younger deformations in the basement of the Moravo-Silesian Variscides, East Sudetes, SW Poland: U–Pb SHRIMP and Rb–Sr age data. Geologia Sudetica 37, 35–51.Google Scholar
Żelaźniewicz, A., Nowak, I., Larionov, A. & Presnyakov, S. 2006. Syntectonic Lower Ordovician migmatite and post-tectonic Upper Viséan syenite in the western limb of the Orlica-Śnieżnik Dome, West Sudetes: U–Pb SHRIMP data from zircons. Geologia Sudetica 38, 63–80.Google Scholar