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Geology,tectonicevolutionandLatePalaeozoicmagmatismofSudetes–anoverview

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Granitoids in Poland, AM Monograph No. 1, 2007, 59-87

Geology, tectonic evolution and Late Palaeozoic magmatism of Sudetes

– an overview Stanisław Mazur, Paweł Aleksandrowski, Krzysztof Turniak,

Marek Awdankiewicz

Abstract: The Sudetic segment of the Variscides, together with adjacent areas, experienced multi-stage accretion during successive collisional events that occurred between Middle Devonian and Late Carboniferous times and followed closure of various segments of the Rheic Ocean. Variscan tectonostratigraphic units exposed in Sudetes are tectonically juxtaposed and often carry a record of contrasting exhumation and cooling paths constrained by palaeontological and geochronological data. The main lithostratigraphical components of the Sudetic segment of the Variscan orogen are: (1) Neoproterozoic complexes derived from an active margin of the Gondwana continent and showing a record of magmatism and metamorphism related to the Cadomian (Panafrican) orogeny, (2) widespread Late Cambrian-Early Ordovician granitic intrusions mostly deformed into gneisses due to Variscan tectonism, (3) Ordovician to Devonian volcano-sedimentary basinal sequences deposited in a continental rift that evolved into an oceanic basin, (4) a low-grade metamorphosed ophiolitic complex of probable Late Silurian age, (5) Early/Middle Devonian to Early Carboniferous sedimentary sequences of actively extending continental margins, (6) Carboniferous granitoid massifs and (7) intramontane basins, superposed on (1) through (5) above, that were initiated in the latest Devonian and Early Carboniferous. Key words: granite, magmatism, volcanism, tectonics, Variscan orogen, Sudetes, Bohemian massif INTRODUCTION

The Variscan orogen of Europe formed due to Late Devonian and Early Carboniferous multi-stage collision of the Gondwana continent with the Laurussia continent (Fig. 1). The Armorican terrane assemblage, together with a number of smaller intervening peri-Gondwanan terranes that had been dispersed across the Rheic Ocean, played a crucial role in this process. The incorporation of these terranes into the Variscan orogenic belt marked the main stages of its growth and was responsible for the large masses of Precambrian and Early Palaeozoic continental crustal material occurring in the European Variscides. The Variscan contractional tectonics had been preceded by rare Late Silurian to Early Devonian continental subduction zones developed as a consequence of the early closure of minor oceanic domains (Pin, Vielzeuf 1983). These initial phases of convergence, accompanied by high pressure metamorphism, were followed by local exhumation of high-grade rocks prior to Late Devonian times, an event often described as the eo-Variscan stage (e.g. Faure et al. 1997). The Variscan tectonism reached its climax in the Late Devonian due to docking of the Armorican terranes with the southern margin of the Old Red continent (Figs. 1 and 2) – mostly represented by the former Avalonian crust (Tait et al. 2000). The compressional regime of the European Variscides persisted

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until the Carboniferous – a time period dominated by intense granite plutonism and extensional collapse of the orogen, coupled with unroofing of metamorphic complexes and simultaneous inversion of foreland basins. At the same time, the main collisional events were taking place farther to the SW, in the area of present-day North Africa and the Appalachians.

Fig. 1. Hypothetical geodynamic scheme of the evolution of Sudetes in the Late Palaeozoic (after Mazur et al. 2006). This palaeogeographic sketch map is inspired by the plate tectonic reconstructions of Ron Blakey (Northern Arizona University). The rectangle and arrow show area analyzed on schematic cross-sections (see Fig. 2).

This chapter provides a comprehensive up-to-date geological overview of the Sudetic part of the Variscan belt. It is based on a compilation of published data and interpretations, and attempts to synthesize currently available evidence. The need for consistency in the arguments and ideas presented here required some simplification of the often complex relationships between the crustal components included in the Sudetic mosaic. TECTONIC SETTING AND SUBDIVISION OF SUDETES

Polish Sudetes define the NE margin of the Bohemian massif (Fig. 2) and contain variously metamorphosed volcano-sedimentary successions and igneous suites of the pre-Carboniferous age. These metamorphic rocks are onlapped by Late Devonian to Carboniferous clastics that were deposited in intramontane troughs and intruded by voluminous, mostly late- to post-orogenic Carboniferous granites. Sudetes, together with the entire Bohemian massif, belong to an extensive belt of uplifts and highs variably elevated during the latest Cretaceous to Cenozoic in response to the build-up of Alpine collision-related intraplate compressional stresses, rifting and mantle plume activity (e.g. Ziegler 1990, Dèzes et al. 2004). To the NE, the uplifted Sudetic internides are juxtaposed, along major faults, against the Variscan external thrust-and-fold belt that subcrops below the thick Permo-Mesozoic succession of the Fore-Sudetic homocline (e.g. Mazur et al. 2006).

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Fig. 2. Hypothetical evolution of Sudetes in the Late Palaeozoic (after Mazur et al. 2006), continued: A – the Góry Sowie-Kłodzko terrane is approaching the Moravian (and Orlica-Śnieżnik) terrane due to closing of the Central-Sudetic oceanic tract; the Moravo-Silesian back-arc basin is initiated in the Early Devonian; B – Central Sudetes are accreted due to continental collision between the Góry Sowie-Kłodzko and Moravian terranes, (U)HP rocks in the Orlica-Snieżnik and Góry Sowie massifs are produced by their subduction to the mantle depths and subsequent exhumation as a nappe pile including the Central Sudetic ophiolite; C – accretion of Sudetes is completed by closing of the Saxothuringian oceanic tract and the Moravo-Slesian back-arc basin, the Kaczawa and South Karkonosze-Leszczyniec units in the west and Moravo-Silesian belt in the east contain remnants of tectonic sutures.

Sudetes represent the most exposed NE part of the Variscan crystalline basement in Europe. They straddle the boundary between Poland and Czech Republic at the NE margin of the Bohemian massif (Fig. 3). The geologically coherent region of Sudetes is divided by the Sudetic boundary fault into two morphologically contrasting domains, namely the low-mountainous ridge of the Sudetic mountains to the SW and the peneplained lowland of the Fore-Sudetic block to the NE. The fault is a Late Variscan fracture zone that was rejuvenated during the latest Cretaceous-Paleocene uplift of the Bohemian massif and again during its Neogene reactivation (Badura et al. 2003). The entire Sudetic area extends between the WNW-ESE trending Middle Odra fault zone in the NE and the parallel Upper Elbe fault zone in the SW (Fig. 3). To the SE, the Variscan basement of the Sudetes plunges beneath the Miocene Carpathian foreland basin whereas, to the NW, it merges with the Neoproterozoic Lusatian massif.

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Fig. 3. For the explanations see the other page. →

Sudetes consist of a mosaic of structurally distinct, fault-bounded pre-Permian units (Fig. 3) that were affected by mostly Devonian to Carboniferous deformation and that are characterized by frequent changes in the dominant structural trends. Variations in geological evolution combine with occurrences of ophiolitic bodies and/or meta-igneous rocks with MORB-like geochemical signatures on some boundaries and the preservation of high-pressure to ultra-high-pressure metamorphic rocks (blueschists, eclogites, granulites) to suggest that the area comprises fragments of distinct tectono-stratigraphic terranes separated by tectonic sutures and major faults and shear zones. The Sudetic

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terranes appear to be the continuation of the Armorican terrane assemblage known form the western parts of Variscan orogen (Winchester, PACE 2002, Aleksandrowski, Mazur 2002). These are the Saxothuringian, Teplá-Barrandian and Moldanubian terranes (Fig. 2) corresponding to the original orogenic zones distinguished by Kossmat (1927). In contrast, the Brunovistulian terrane at the eastern termination of Sudetes may a form part of Eastern Avalonia (Friedl et al. 2000) or belong to the peri-Baltica terranes of the Trans-European suture zone (Belka et al. 2002).

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Sudetes are divided into western, central and eastern parts because of important differences in their lithostratigraphy, structure and geological evolution (Fig. 4). West Sudetes comprise the eastern parts of the Lusatian massif, the Karkonosze-Izera massif, the Kaczawa complex and the Görlitz slate belt, all of which were deformed between the Late Devonian and Late Carboniferous. The deformation climax, accompanied by orogenic uplift, took place during the Early Carboniferous and was followed, from the latest Carboniferous onward, by sedimentation in the intramontane North-Sudetic Permo-Mesozoic basin.

Central Sudetes include the Góry Sowie massif together with the surrounding bodies of the Central Sudetic ophiolite, the Kłodzko and Orlica-Śnieżnik massifs, the Nové Město, Staré Město and Kamieniec metamorphic belts, the Niemcza and Skrzynka shear zones as well as the Niedźwiedź amphibolite massif. These are partly covered by the intramontane Bardo and Świebodzice basins, initiated during the Late Devonian, and by the Intra-Sudetic basin that began to subside during the middle Viséan (Turnau et al. 2002). The main deformation of this area occurred at the Middle to Late Devonian transition and soon followed by regional uplift and a succession of overprinting Carboniferous tectonic pulses.

East Sudetes form a part of a collisional belt that developed at the eastern margin of the Bohemian massif. They comprise a nappe pile of the Moravo-Silesian units representing detached Bruno-Vistulian basement overridden from the west by the Central Sudetic Orlica-Śnieżnik massif and the Staré Město belt. From top to bottom, or in map view from west to east, the East Sudetic nappe pile comprises the Velké Vbrno and Keperník nappes resting on parautochthonous gneisses of the Desná unit (Schulmann, Gayer 2000) and covered by the allochthonous Devonian volcano-sedimentary Vrbno group (Fig. 4). Towards the east, they adjoin the thrust-

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folded Lower Carboniferous fill of the Moravo-Silesian foreland basin.

Fig. 4. Geological sketch map of the Sudetes (after Aleksandrowski et al. 1997). BU – Bardo sedimentary unit; EFZ – Elbe fault zone; ISF – Intra-Sudetic fault; KMB – Kamieniec metamorphic belt; KU – Kłodzko metamorphic unit; LM – Lusatian massif; MGCH – Mid-German crystalline high; MO – Moldanubian zone; NP – Northern phyllite zone; NZ – Niemcza shear zone; OFZ – Odra fault zone; OSD – Orlica-Śnieżnik dome; RH – Rhenohercynian zone; SU - Świebodzice sedimentary unit; SBF – Sudetic boundary fault; ST – Saxothuringian zone; SZ – Skrzynka shear zone. Granite intrusions: BG – Bielice tonalite; JG – Jawornik granitoid; KOG – Kudowa-Olešnice granite; KZG – Kłodzko-Złoty Stok granite; NG – Niemcza granitoid; OG – Odra granites; WG – Walim granite; ZG –Żeleźniak granite. Age assignments as in Fig.3. LITHISTRATIGRAPHIC CHARACTERISTICS

Sudetes expose a variety of metamorphic complexes of Neoproterozoic, and Lower Palaeozoic to Devonian protoliths (Fig. 4). The Neoproterozoic complexes most likely represent splinters derived from an active margin of the Gondwana continent. They record magmatism and metamorphism related to the Cadomian (Panafrican) orogeny that occurred at ca. 530-600 Ma (Kröner et al. 1994, Buschmann et al. 2001, Oberc-Dziedzic et al. 2003, Mazur et al. 2004). These complexes consist of (1) plutonic and volcano-sedimentary rocks with magmatic arc and back-arc basin affinities in the Kłodzko metamorphic massif, (2) granitoids intruded into greywackes in the Lusatian massif and

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East Sudetes and, most probably, (3) pelitic series of poorly constrained age enveloping Early Palaeozoic granitoid intrusions in the Izera-Karkonosze and Orlica-Śnieżnik massifs (Gunia 1984, Kröner et al. 2001). The Lusatian granitoids were emplaced at 540-530 Ma (Kröner et al. 1994, Tikhomirova 2002) during the final phases of the Cadomian orogeny (Linnemann et al. 2000). They are characterized, at most, by a weak deformation fabric. The eastern margin of the Lusatian massif extending into Poland across the Polish-German border hosts the Zawidów granodiorite – a local variety of the Lusatian granitoids.

Late Cambrian-Early Ordovician granitic intrusions are widespread in Sudetes, as in several other regions of the Variscan belt. These granites, mostly deformed into gneisses due to Variscan tectonism, are believed to have been intruded during a phase of continental rifting (e.g. Oberc-Dziedzic et al. 2005). Locally they have preserved a record of Ordovician low pressure-high temperature metamorphism that reflects thinning of the continental crust (Kröner et al. 2000, Štipska et al. 2001). A virtually undeformed variety of the Late Cambrian granites cropping out in the Karkonosze-Izera massif is traditionally defined as the Rumburk granite.

The Ordovician to Devonian volcano-sedimentary basinal sequences of the Kaczawa complex and southern Karkonosze-Izera massif were deposited in an Ordovician continental rift that evolved during the Silurian-Devonian into an oceanic basin (Furnes et al. 1994, Patočka, Smulikowski 2000). They contain Ordovician rift-related intraplate bimodal volcanics, Silurian MORB-type metabasalts and Silurian-Devonian deep marine deposits (cherts). In the eastern part of the Izera-Karkonosze massif the Leszczyniec meta-igneous unit, composed of Ordovician mafic, mostly MORB-type rocks of the basalt or gabbro protliths associated with plagiogranite and tonalite gneisses, defines a system of plutonic and subvolcanic intrusions.

The little metamorphosed circum-Góry Sowie (Central Sudetic) ophiolite displays almost all the members of a typical ophiolite succession – serpentinized ultramafics, massive gabbros and cumulates, sheeted dykes, pillow lavas and deep marine radiolarian cherts (Majerowicz 1981). This ophiolite has yielded a Late Silurian-Early Devonian 420-400 Ma age (Oliver et al. 1993, Dubińska et al. 2004).

In East Sudetes (Vrbno unit), the Görlitz slate belt and the Ješted unit are composed of Early or Middle Devonian to Early Carboniferous sedimentary sequences that were deposited on actively extending continental margins. These are typified by a transition from mostly carbonatic Devonian shelf deposits to Carboniferous turbidites and/or mélanges in the Görlitz slate belt. The distinctive Vrbno group is interpreted as the volcanic-sedimentary fill of a Middle-Late Devonian back-arc basin (Patočka, Valenta 1996).

The metamorphosed and exhumed Sudetic rock complexes formed the substratum for authochtonous intramontane basins. These began to subside during the Late Devonian (Bardo and Świebodzice basins) and Early Carboniferous (the Intra-Sudetic basin). STRUCTURE

Sudetes developed during Devonian and Early Carboniferous times in response to closure of one or more marine basins floored by oceanic crust, concomitant amalgamation of the Armorican terranes (Fig. 1), and their accretion to the Trans-European suture zone collage flanking the East-European platform (cf. Matte et al. 1990, Cymerman et al.

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1997, Belka et al., 2002, Franke, Żelaźniewicz 2000, Aleksandrowski, Mazur 2002, Winchester, PACE 2002).

The vestiges of these marine basins are the allochthonous volcanic-sedimentary complexes of the Kaczawa Mts. and the southern and eastern Karkonosze Mts. These are involved in nappe piles that were thrust towards the NW (Mazur, Kryza 1996, Seston et al. 2000, Mazur, Aleksandrowski 2001). The basins represent tectonic sutures, as evidenced by meta-igneous rocks of MORB-type affinity associated with deep marine sediments (Furnes et al. 1994, Winchester et al. 1995, Kryza et al. 1995, Patočka, Smulikowski 2000) and by a record of high-pressure, blueschist-facies metamorphism (Kryza et al. 1990, Smuliko ski 1995, Kryza, Mazur 1995), the later overprinted by greenschist facies alteration. In the nappe piles, thrust sheets containing MORB-type rocks override thrust units containing intraplate volcanics. In the Kaczawa Mts., mèlange bodies, often less metamorphosed than their host rocks, form an important part of the nappe pile (Baranowski et al. 1990, Collins et al. 2000).

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Fig. 5. Simplified stratigraphic columns for the main structural units of the Sudetes (modified from Aleksandrowski, Mazur 2002). Metamorphic rocks are represented by their sedimentary and igneous protoliths. LU – Leszczyniec unit, SK – South Karkonosze unit, Jst – Ještěd unit.

The metamorphic nappes of the S and E Karkonosze-Izera massif and those of the Kaczawa Mts., are thrust onto continental crust that is considered to form part of the pre-Variscan passive margin of Saxothuringian terrane (e. g. Mazur, Aleksandrowski 2001). aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

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This continental crust corresponds to the crystalline complexes of the Lusatian (Linnemann et al. 2000) and Karkonosze-Izera massifs (e.g. Matte et al. 1990, Mazur, Aleksandrowski 2001). To the east, within the Karkonosze-Izera massif, the Neoproterozoic rocks were massively intruded by Early Ordovician granitoids later deformed into orthogneisses by Variscan tectonism. These granitoids were emplaced during the rifting stage of the eastern margin of the Saxothuringian terrane; the syn- and post-rift sedimentary-volcanic cover, now only fragmentarily preserved, comprises the Ješted unit within the Karkonosze-Izera massif and the Torgau-Doberlug "syncline", and the Görlitz slate belt in the immediate neighborhood of the Lusatian massif. The Görlitz slate belt also constitutes a parautochthonous basement that was overthrust by the allochthonous units of the Kaczawa nappe stack (Aleksandrowski, Mazur 2002).

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The tectonic sutures, which rest on the allochthonous units of the Kaczawa nappes and of the southern and eastern parts of the Karkonosze-Izera massif, are to the east covered by Late Palaeozoic sedimentary basins. Metamorphic complexes, constituting upper plate thrusts that cover the sutures zones, form the substrate of these basins. The Intra-Sudetic basin to the east of the Karkonosze-Izera massif developed during the late middle Viséan (Turnau et al. 2002) in response to a top-to-ESE directed extension (Mazur, Aleksandrowski 2001). The Świebodzice basin, east of the Kaczawa nappe complex, was initiated in the latest Devonian as a piggy-back basin.

The tectonic units of Central Sudetes, located east of the Intra-Sudetic and Świebodzice basins, are mostly, if not entirely, allochthonous. These are the metamorphic massifs of Góry Sowie, Kłodzko, Orlica-Śnieżnik and Nové Město and the Central Sudetic ophiolite (Fig. 3). The latter is the vestige of the oceanic basin, closure of which resulted in the development of the Sudetic segment of the Variscan belt. The Central Sudetic ophiolite is little metamorphosed whereas the Góry Sowie and Orlica-Śnieżnik massifs contain high-pressure granulites (Kryza et al. 1996) indicating that these units were derived from subducted continental crust. Granulites from the Orlica-Śnieżnik massif recorded an early ultra-high pressure metamorphism (Anczkiewicz et al. 2007) and are associated with high-pressure eclogites. The Central Sudetic tectonic units were presumably thrust to the NW although this conclusion is based entirely on data from the Kłodzko massif (Mazur et al. 2004). At the boundary of the Orlica-Śnieżnik and Nové Město units, an opposite top-to-SE polarity of thrusting has been recorded (Mazur et al. 2005). However, in this instance, the lack of metamorphic grade inversion indicates that the contact between these two tectonic units may be a back-thrust.

In general, Central Sudetes comprise structural units that correspond to Neoproterozoic to Cambrian volcano-sedimentary sequences (Gunia 1999, Mazur et al. 2004) and units dominated by Early Ordovician granite bodies (cf. e. g. Oliver et al. 1993, Turniak et al. 2000, Kröner et al. 2001). In contrast to West Sudetes, Central Sudetes do not contain Early Palaeozoic volcano-sedimentary sequences that were deposited in open marine basins (with the exception of rare olistoliths in the Bardo basin).

East of the Orlica-Śnieżnik massif, and separated from it by a suture zone referred to as the Staré Město belt, there occurs the East Sudetic nappe complex (Fig. 3). The Staré Město belt is mostly composed of rocks derived from an Early Ordovician rift that record a rift-related high temperature-low pressure metamorphism (Kröner et al. 2000, Štipska et al. 2001). These rocks are intruded by synorogenic tonalites of ca. 340 Ma age (Parry et al. 1997). The East Sudetic nappe complex forms part of the NE-SW striking Moravo-Silesian zone, located along the eastern margin of the Bohemian massif. It traces the suture zone between the Armorican terrane assemblage, represented here by Central Sudetes, and the adjacent Bruno-Vistulian terrane to the east. The crystalline crust of the latter is composed of Neoproterozoic metamorphic and intrusive rocks covered by Palaeozoic sediments. On the western margin of the Bruno-Vistulian terrane, this sedimentary succession commences with Early Devonian basal conglomerates and quartzites that grade upward into Middle-Late Devonian platform carbonates and Early Carboniferous, syn-orogenic turbidites of the Moravo-Silesian foreland basin.

The East Sudetic nappe system contains detached fragments of the Neoproterozoic Bruno-Vistulian basement and metamorphosed sediments from its cover (Schulmann, Gayer 2000). The tectonically lowermost element is a 3000 m thick allochthonous sequence of Middle Devonian shales and volcanics (Vrbno series) that represents the fill of a back-arc basin (Patočka, Valenta 1996). The East Sudetic nappes were thrust NE

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-ward in a dextral transpressional regime (Matte et al. 1990, Schulmann, Gayer 2000). The structural plan is dominated by NE-SW to NNE-SSW trending lineations that characterise not only the East Sudetic nappe complex, but also the adjacent part of the Central Sudetes, particularly the Orlica-Śnieżnik massif.

Two important WNW-ESE wrench fault and shear zones, the Upper Elbe and the Intra-Sudetic fault zones, hamper correlations between Sudetes and the remaining parts of the Bohemian massif, and of particular Sudetic units with each other. Although the magnitude of displacement along these fault zones is still a matter of controversy (Aleksandrowski 1990, Matte et al. 1990, Oliver et al. 1993, Aleksandrowski et al. 1997), they delimit all adjacent structural units and, thus, make a reliable transregional correlation difficult. Tectonic activity along both of these fault zones ceased essentially after Late Carboniferous sinistral displacement that may have locally attained 15-20 km and which was preceded by Late Devonian-Early Carboniferous dextral displacements (Aleksandrowski et al. 1997, Mattern 2001). TIME CONSTRAINTS

The accretion of the Sudetic segment of the Variscides was a multi-stage process. The oldest recorded tectono-metamorphic events took place at the Silurian/Devonian transition. In the Góry Sowie massif, the high-pressure granulites have been dated at 400-395 Ma (O’Brien et al. 1997) and, in the Orlica-Śnieżnik massif, at 386 Ma (Anczkiewicz et al. 2007). These testify to the subduction of continental crust shortly after accretion of oceanic crust, corresponding to the Central Sudetic ophiolite formation (420-400 Ma; Oliver et al. 1993, Dubińska et al. 2004), had ended (Fig. 1). During subsequent emplacement of nappes, including ophiolites and metamorphic complexes, fragments of the subducted continental crust were exhumed. An Early Givetian fauna from metamorphic sediments of the Kłodzko metamorphic massif constrains the lower time limit of the nappe emplacement (Hladil et al. 1999). The upper age limit of this event is provided by a pre-Late Devonian unconformity on top of the ophiolites and the nearby Kłodzko metamorphic massif that is overlain by unmetamorphosed Late Frasnian to Famennian limestones (Bederke 1924, Kryza et al. 1999). These Late Devonian carbonates grade upward into the Early Carboniferous clastic sequence of the Bardo basin (Haydukiewicz 1990, Wajsprych 1986). Consequently, the emplacement and exhumation of the Central Sudetic nappes must have taken place within a narrow time span between ca. 390 and 380 Ma.

In the more westerly located Kaczawa basin of West Sudetes, however, deep-water sedimentation lasted until the end of Devonian times, suggesting that the Kaczawa successions were incorporated into an accretionary prism as late as end-Devonian times. This is compatible with the occurrence of metamorphic rocks of blueschist facies in the adjacent Karkonosze-Izera massif that yielded an age of ca. 360 Ma (Maluski, Patočka 1997). The final thrusting of the nappes of the Kaczawa Mts. and of the S and E parts of the Karkonosze massif over the eastern margin of Saxothuringian terrane occurred not earlier than during the Viséan. This conclusion is supported by the age of sediments underlying these allochthonous units in the Ještěd unit (Chlupač 1993) and at the western end of the Kaczawa nappe pile (Chorowska 1978).

The collision of the Central Sudetes orogenic wedge with the Bruno-Vistulian terrane commenced during the earliest Carboniferous and lasted until the turn of the Early and Late Carboniferous (Schulmann, Gayer 2000). During these times, tectonic activity in the other parts of Sudetes was dominated by strike-slip motions along major faults and shear

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zones, localized gravitational collapse, and intense granitic plutonism. Top-to-SE extensional exhumation of the Karkonosze-Izera massif, dated as 340 Ma, is documented from the eastern margin of the massif (Mazur, Aleksandrowski 2001). Dextral strike-slip displacements occurred at that time not only along the WNW-ESE trending Upper Elbe and Intra-Sudetic fault zones (Aleksandrowski et al. 1997, Mattern 2001), but also along the boundary between the Nové Město unit and the Orlica-Śnieżnik massif (Mazur et al. 2005). Contemporaneous sinistral displacements occurred on the NNE-SSW striking Niemcza shear zone (Mazur, Puziewicz 1995) and the NE-SW trending Złoty Stok-Skrzynka shear zone (Cymerman 1996). Granitic plutonism climaxed at 310-300 Ma (see below), resulting in the emplacement of several large plutons, such as those of Karkonosze, Strzegom-Sobótka, Złoty Stok, Strzelin and Żulova (Fig. 3). VARISCAN GRANITOIDS

Early Carboniferous granitoids include a number of variably sized intrusions dispersed across Central Sudetes and in the vicinity of the Odra fault zone (Fig. 1). They comprise the Odra, Niemcza and Jawornik granitoid bodies, the Kłodzko-Złoty Stok and Kudowa-Olešnice massifs, as well as the Staré Město (Bielice) tonalite sill.

Late Carboniferous granitoids are the most voluminous intrusions both in West and East Sudetes. They include the shallow, mostly undeformed Karkonosze, Strzegom-Sobótka and Strzelin plutons with wide contact aureoles, as well as plutonic to subvolcanic bodies represented by the Żeleźniak intrusion.

Granitoids of the Odra fault zone The granitoids of the Odra fault zone (Fig. 1) are hosted by greenschist to amphibolite facies metasediments and entirely buried under Cenozoic cover. Their subcrop areas are known as the Gubin, Szprotawa, Środa Śląska, Wrocław and Grodków granitoids. These correspond to small bodies of mostly brittlely deformed, unfoliated hornblende granodiorites, monzogranites and subordinate granites, tonalities and quartz diorites. These rocks are high-potassic, metaluminous or, less commonly, peraluminous and show high variability in aluminosity and calc-alkalinity (Oberc-Dziedzic 1999). Rb-Sr studies of the Grodków granites drilled in the eastern part of the Odra fault zone provided whole-rock age values of ca. 332 Ma and ca. 338 Ma, respectively (Pieńkowski, pers. comm. 1998 – fide Oberc-Dziedzic et al. 1999). Dörr et al. (2006) reported an age value of 344 ±1 Ma (ID-TIMS method, single zircons) for the undeformed hornblende granodiorite in Szprotawa granitoids and for the hornblende monzonite showing magmatic foliation, the rock belonging to the Środa Śląska granitoids.

Niemcza granitoids In the N-S trending, 20 km long and 5 km wide Niemcza shear zone (Fig. 1), mylonitized gneisses of the adjacent Góry Sowie massif enclose several small bodies of late-tectonic granitoids (Dziedzicowa 1963, Mazur, Puziewicz 1995). The Niemcza granitoids comprise mostly medium-grained, sometimes porphyritic, weakly foliated granodiorites and fine-grained quartz syenite, monzodiorite and vaugnerite. They are metaluminous, calc-alkaline, alkali-calcic to calcic. The Sri value is estimated by Lorenc (1996) to range from 0.7063 (diorite from Przedborowa) to 0.7083 (granitoid from Kośmin). Granodiorites crystallized from magma at 730-850°C and 4 ±1 kbars and they underwent late-magmatic, non-coaxial deformation (Puziewicz 1992). The age of the Niemcza granitoids emplacement and cooling to ca. 500°C is well constrained by U-Pb and 40Ar/39Ar data. The U-Pb age of a syenite at Koźmice is 338±2,3 Ma (ID-TIMS method,

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the analysed minerals zircon and sphene, see Oliver et al. 1993) and the cooling age of a syn-kinematic granodiorite is 331.9 ±1.7 Ma (40Ar/39Ar method, hornblende was the analysed mineral, see Steltenpohl et al. 1993).

Kłodzko-Złoty Stok and Kudowa-Olešnice massifs The Kłodzko-Złoty Stok massif (Fig. 1), the largest (120 km2) exposed Early Carboniferous intrusion, is compositionally variable and comprises granodiorites, quartz monzodiorites, monzodiorites, tonalites and granites. Details of their petrographic and chemical characteristic were given by Wierzchołowski (1976) and Lorenc (1994). A typical feature of the massif is the occurrence of roof pendants composed of metamorphic and sedimentary rocks (Wojciechowska 1975). Their presence indicates a present day level of exposure close to the roof of the pluton. The granitoids host numerous mafic enclaves and are mostly metaluminous, calc-alkaline to calcic, or calc-alkaline rocks (Lorenc 1994). The Kłodzko-Złoty Stok massif is traditionally considered to be roughly contemporaneous with the nearby Kudowa-Olešnice massif. The later was dated by means of the Rb-Sr whole-rock method at 331±11 Ma (Bachliński, Hałas 2002).

Jawornik granitoids The Jawornik granitoids represent a syn-tectonic intrusion in the Złoty-Skrzynka shear zone (Fig. 1), comprising foliated, fine- to medium-grained biotite granodiorites, tonalites with minor hornblende granodiorites and monzogranites. These rocks form NW-ward dipping sills and dykes up to ca. 1 km thick and partly concordant with the foliation of the country rocks. The granitoids are generally weakly metaluminous to mildly peraluminous, subalcalic, calc-alkaline and are classified as I-type granite. Hornblende and biotite from the hornblende-biotite granite yielded the age values of 351.1±3.7 Ma and 349.6±3.8 Ma, respectively, whereas muscovite from the biotite-muscovite granite is dated at 344.6±3.8 Ma (40Ar/39Ar method; Białek, Werner 2004). The granitoids probably crystallized at 660-730°C temperatures and under pressures of and 5.5 kbars, respectively, corresponding to a depth of ca. 18-23 km (Białek 2003).

Staré Město tonalite An about 1 km thick and 60 km long tonalitic sill occurs at the NE margin of the Bohemian massif, in the Staré Město belt. This granitoid body is composed of mostly foliated medium-grained granodiorites, tonalites and monzogranites (Wierzchołowski 1966). They appear to have crystallized at a depth of 18-24 km, corresponding to a pressure of 5-7 kbars, at 710-730°C (Parry et al. 1997). The age of emplacement is 339 ±7 Ma (Pb-evaporation method on zircon; Parry et al. 1997).

Karkonosze granite pluton The Karkonosze pluton, the largest exposed granite massif in the Sudetes, is mostly composed of biotite granite. Four main granite facies predominate (Borkowska 1966): (1) porphyritic coarse-grained granite with K-feldspar phenocrysts often mantled by plagioclase, (2) medium grained granite, (3) fine to medium, equigranular granite, and (4) granophyric granite. The mineral composition of the Karkonosze granite is dominated by quartz, K-feldspar, plagioclase and biotite with allanite, zircon and apatite as main accessories. Porphyritic and granophyric varieties contain, in addition, small amounts of hornblende.

Most of its geochemical, petrological and mineralogical features suggest that the Karkonosze granite can be classified as KCG (K-rich calc-alkaline granitoid) in the classification of Barbarin (1999). The poprhyritic variety contains numerous

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microgranular mafic enclaves and schlieren. Zircon crystals are mostly of P-type in the classification of Pupin and Turco (1972) and typical of I type granitoids (Pupin 1985). The Karkonosze granite is slightly peraluminous with A/CNK mostly <1.1. The initial Sr isotopic ratio ranges from 0.7056-0.7073 (Duthou et al. 1991). The value of εNd(320) varies from –7 to –4 for the porphyritic granite through –4 to –3 for granodioritic hybrids to –2 to –1 for lamprophyres (Słaby, Martin 2005). Major element modelling and feldspar analyses suggest that two mechanisms were particularly important in magma differentiation: (1) mixing of felsic magma assumed as from the lower crust and mafic magma possibly derived from metasomatized mantle at the early stages of pluton formation and (2) fractional crystallization of more evolved melts (Słaby, Götze 2004, Słaby, Martin 2005).

Early geochronological studies of the Karkonosze granite provided K-Ar age values of 298-323 Ma (Borucki 1966, Depciuch, Lis 1971). The Rb-Sr whole-rock age values of 329±17 Ma for the porphyritic granite (Michałowice quarry), 328±12 Ma for schlieren granite (Szklarska Poręba Huta quarry) and 309±3 Ma for fine-grained, equigranular granite were considered to reflect the emplacement age of these granite varieties (Duthou et al. 1991). Machowiak and Armstrong (2007) obtained zircon (the SHRIMP method) age values of 318.5±3.7 Ma, 314.9±4.5 Ma and 314.1±3.3 Ma for the porphyritc granite from Radomierza, for the Miedzianka granite and for the Fajka Hill granite, respectively. A similar though less precise age of 304±14 Ma was estimated by Kröner et al. (1994) for the porphyritic granite. The Ar-Ar age values of 320±2 Ma (biotite porphyritic granite) and 312±2 Ma (muscovite-biotite granite) date the cooling of the pluton to temperatures in the range of 300-350oC (Marheine et al. 2002). Similar Rb-Sr mineral age values of 311 and 318 Ma were determined by Borkowska et al. (1980).

Żeleźniak intrusion The high crustal-level subvolcanic intrusion of the granodioritic type magma at Żeleźniak Hill crops out in a small area of ca. 500 m in diameter. Volcanic rocks (rhyolites, rhyodacites, dacites, trachyandesites) are associated there with fine-grained porphyritic microgranites and coarse-grained equigranular granodiorites. The granitoids are peraluminous with Sri in the range of 0.7086 to 0.7288 and are classified as S-type granites (Machowiak et al. 2004). The Żeleźniak magmatic body is interpreted as a multi-pulse injection lava dome that occasionally vented to the surface (Machowiak et al. 2004). The rhyodacites and granites forming the intrusion have been dated (U-Pb age by the SHRIMP method) at 315±1.8 Ma and 316.7±1.2 Ma, respectively (Muszyński et al. 2002). The inherited component of the zircon crystals yielded a U/Pb age of 2598.2±4.6 Ma and of 2063±13 Ma (Muszyński et al. 2002). The Au-As-Cu mineralization at Stara Góra, genetically linked to the Żeleźniak intrusion, is dated at 317±17 Ma (Mikulski et al. 2005). A similar age of 316.6±0.4 Ma was obtained for arsenopyrite from the gold-bearing Klecza-Radomice ore body in the Kaczawa Mountains and in the close vicinity of the Karkonosze pluton (Mikulski et al. 2005).

Strzelin massif The Strzelin massif comprises granodiorites, quartz diorites, tonalites, biotite- and two-mica granites as isolated bodies, mostly stocks and flat-lying dykes ranging up to tens of metres thick (Oberc-Dziedzic et al. 1996). Whole-rock geochemical data indicate a metaluminous, calc-alkaline features for the constituent tonalite, quartz diorite and biotite granite. These rocks are described as HCa (low K – high Ca) calc-alkaline granitoids by Oberc-Dziedzic et al. (1998) in the classification of Barbarin (1990). The emplacement and crystallization of the Strzelin granite took place at pressures of 1.5-3 kbar (Pietranik

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et al. 2006) as indicated by the presence of andalusite in the two-mica granite and by the Al-content in hornblende from the tonalite.

The biotite granite and two-mica granite were dated at 347±12 Ma and 330±6 Ma, respectively (Rb-Sr whole-rock data; Oberc-Dziedzic et al. 1996). The most recent Rb-Sr age values obtained for the tonalite range between 293.8±0.3 Ma and 296.7±0.7 Ma (Pietranik, Waight, pers. comm. 2007). Equally young Pb-evaporation zircon age values of 291±5.5 Ma and 301±7 Ma are reported by Turniak et al. (2006) for the tonalite and biotite granite, respectively. K-Ar cooling age values for the granitoids, varying from 278 to 288 Ma (Depciuch, Lis 1972), are in general agreement with Ar-Ar results obtained for white micas from the country rocks (279.4±1.8 to 284.6±2 Ma; Szczepański 2002).

Strzegom-Sobótka massif The Strzegom-Sobótka massif (Fig. 1) is composed of four main granite varieties: (1) hornblende-biotite monzogranite, (2) biotite monzogranite, (3) two-mica monzogranite, and (4) biotite granodiorite (Majerowicz 1972, Puziewicz 1990). The peraluminous two-mica monzogranite is thought to have crystallized from almost water-saturated, relatively cold magma, as concluded from its low Sri = 0.705, the presence of schistose enclaves composed mostly of biotite and muscovite, and the abundance of primary magmatic muscovite (Puziewicz 1990). The two-mica granite is probably the oldest rock type and is not genetically related to the other granitoids of the Strzegom-Sobótka massif. Pin et al. (1989) reported an age of 324±7 Ma (Rb-Sr method on biotite) for this rock. Younger monazite and xenotime age values of 309.1±0.8 Ma and 306.4±0.8 Ma, respectively (U-Pb ID-TIMS method; Turniak, Bröcker 2002) probably reflect magmatic activity related to the adjacent intrusion of the biotite granodiorite. The latter is dated at 308.4±1.7 Ma (Pb-evaporation method on zircon; Turniak et al. 2005) and shows pronounced changes in chemical composition from the east to west, manifested in an increase in Fe, Mg, Al, Ti and P and a simultaneous decrease of Si content (Puziewicz 1990). The granodiorite contains mafic enclaves of tonalitic composition (Majerowicz 1963). The low Sri=0.7058 suggests that the granodiorite was formed from magma poor in radiogenic Sr (Pin et al. 1989).

The western part of the Strzegom-Sobótka massif consists of hornblende-biotite monzogranites with minor biotite granite. The latter seems to display the mineralogical and geochemical features transitional between the granodiorite and the hornblende-biotite monzogranite (e.g. biotite composition, zircon forms and habits, initial 87Sr/86Sr). The hornblende-biotite monzogranite must have crystallized from water-undersaturated magma (T>850°C) mainly of crustal origin, though the magma of the biotite variety contained less water and may have been be derived from a different source (Puziewicz 1990). An abundance of primary miarolitic pegmatites suggests that the hornblende-biotite monzogranite intruded at depths of 3-5 km (Janeczek 1995). The hornblende-biotite monzogranite and the in it enclaves both show calc-alkaline, peraluminous to metaluminous characteristics. The crustal affinity of the monzogranites is indicated by Sri = 0.710 (Pin et al. 1989, Domańska-Siuda 2006) and εNd(290), ranging from ca. –7.1 to –2.2 (Domańska-Siuda 2006). On the basis of geochemical modeling, Domańska-Siuda (2006) demonstrated that the magmatic evolution of the hornblende-biotite monzogranite was mostly controlled by fractional crystallization of plagioclase and, to a lesser extent, of biotite and amphibole, and by subordinate mixing with small portions of mafic magma. The age of the hornblende-biotite monzogranite emplacement and the rate of cooling remain poorly constrained. Pin et al. (1989) reported age values of 278±7 Ma and 281±12 Ma for the hornblende-biotite and biotite varieties, respectively (Rb-Sr method).

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Similar age values were reported by Domańska-Siuda (2006) for the hornblende-biotite granite and mafic enclaves. Zircon Pb-evaporation dating yielded a significantly older age of 302.9±2.2 Ma interpreted as a minimum age of zircon crystallization in the hornblende-biotite variety (Turniak et al. 2005). The biotite monzogranite was dated at 307.2±4.4 Ma by the same method. Comparable age values ranging from 304±1 to 309±1 Ma were obtained from Re-Os studies on molybdenite from quartz veins cross-cutting the hornblende-biotite monzogranite (Mikulski, Stein 2005).

The K-Ar cooling age values for the Strzegom-Sobótka granitoids cluster into two groups. The older comprises 308.8±4.6 Ma and 305.5±4.3 Ma values obtained from the biotite granodiorite. These data are generally consistent with the zircon crystallization age of 308.4±1.7 Ma (Turniak et al. 2005) that implies rapid cooling from magmatic temperatures down to the biotite K-Ar closure temperature. The younger age group comprises values of 291.0±4.4 Ma and 298.7±5.2 Ma for the hornblende-biotite monzogranite and of 294.2±4.3 Ma for the biotite monzogranite (Turniak et al. 2007). CARBONIFEROUS AND PERMIAN SUBVOLCANIC AND VOLCANIC ROCKS

Distribution and age The late Palaeozoic magmatism in Sudetes included, apart from the granitoid plutonism, widespread subvolcanic to volcanic activity. The resulting igneous complexes may be broadly subdivided into: (1) subvolcanic complexes of dykes and other hypabyssal intrusions exposed within uplifted crystalline basement blocks and (2) volcanic complexes of lavas, shallow-level intrusions and volcaniclastic deposits interstratified in Permo-Carboniferous sedimentary successions in the intramontane Intra-Sudetic and North-Sudetic basins (Fig. 5). The subvolcanic complexes generally post-dated the granitic plutonism and formed in Carboniferous to Permian times. However, radiometric dating is lacking except for two zircon age values obtained by the SHRIMP method: 1) from the Żelaźniak intrusion (ca. 315-316 Ma; Muszyński et al. 2002) and 2) from a micromonzodiorite dyke within the Karkonosze granite (ca. 318 Ma, preliminary result; Awdankiewicz et al. 2007). The age of volcanic activity within the intramontane troughs is, to date, constrained only by geological and stratigraphic evidence indicating that volcanism commenced in the Carboniferous and reached its climax during the Permian.

Subvolcanic complexes Mafic to felsic dykes (lamprophyres and various “porphyries”) are widely distributed within the crystalline basement rocks of the Sudetes and locally concentrate into small dyke swarms (Fig. 5). The Kowary-Janowice Wielkie swarm in the Karkonosze-Izera massif cuts the eastern part of the Karkonosze granite, shows the greatest petrographic variation and comprises minettes, vogesites, spessartites as well as monzodioritic to microgranitic rocks (Awdankiewicz et al. 2005, and his unpublished data). The Złoty Stok swarm is associated with the Kłodzko-Złoty Stok granitoid intrusion and shows a similar range of petrographic variation except for minettes which are absent (Wierzchołowski 2000, Awdankiewicz 2007). However, a small dyke swarm near Gniewoszów that cuts the metamorphic rock series of the Orlica-Śnieżnik massif consists almost exclusively of minettes (Awdankiewicz 2007). Rare lamprophyre dykes cutting Carboniferous deposits are also found in the Góry Sowie massif and in the Intra-Sudetic basin (Muszyński 1987, Awdankiewicz et al. 2004).

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The Żelaźniak intrusion is a distinctive subvolcanic complex. It is emplaced within the low-grade metamorphic rocks of the Kaczawa complex and consists of an irregular central intrusion and several veins. The igneous rocks comprise rhyolites, dacites, trachyandesites, lamprophyres and, at a deeper level, granitoids (Muszyński et al. 2002, Machowiak et al. 2004). The Żelaźniak intrusion possibly represents a deeply eroded remnant of a central volcano.

Fig. 6. Geological sketch of the Sudetes region showing the distribution of the Carboniferous and Permian volcanic and subvolcanic rocks. KIM – Karkonosze-Izera massif, GSM – Góry Sowie massif, OSM – Orlica-Śnieżnik massif, ISB – Intra-Sudetic basin, NSB – North-Sudetic basin, MSF – marginal Sudetic fault. ZI – Żelaźniak intrusion.

The subvolcanic rock suites, and especially the lamprophyres, are characterized by hydrous phenocryst assemblages with abundant phlogopite-biotite and calcic amphiboles (e.g. kaersutite, magnesiohastingsite) accompanied by clinopyroxenes (diopside to augite) and pseudomorphs after olivine.

Some minettes and other lamprophyres contain abundant Na-rich amphiboles (richterite, winchyte, arfvedsonite and riebeckite; Awdankiewicz et al. 2005). More felsic dyke rocks contain biotite, feldspar and quartz phenocrysts. However, the original petrographic variation is partly obscured by a common post-magmatic replacement of the primary minerals by sericite, albite, chlorite, actinolite, epidotes and other minerals.

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Volcanic complexes The most complete record of the Late Palaeozoic volcanism is found in the Intra-Sudetic basin where Lower Carboniferous, Upper Carboniferous and Lower Permian volcanic complexes are recognized (Awdankiewicz 1999a, b, and references therein). In the Carboniferous times, rhyodacitic to rhyolitic lava flows, laccoliths and volumetrically minor sills of andesite to basaltic andesite composition were emplaced in the area of the Wałbrzych coal basin which represented an intrabasinal depositional trough. The formation of laccoliths and sills was facilitated by thick accumulations of young, poorly-lithified sediments which trapped the rising magmas at shallow subvolcanic levels (Awdankiewicz 2004). However, in the eastern part of the Wałbrzych basin, a belt of diatremes is the remnant of maar-type volcano zone which formed due to phreatomag-matic eruptions of rhyolitic magmas, with subsequent intrusion of rhyolitic and trachyan-desitic dykes, sills and domes.

The volcanism culminated in the Permian times and abundant volcanic complexes formed both within the Intra- and North-Sudetic basins. The volcanic products range from basic to acidic in composition and several volcanic centres, often related to effusive volcanism, can be distinguished. Well recognized examples at the western limb of the Intra-Sudetic basin include a basaltic trachyandesite shield volcano near Kamienna Góra and the rhyolitc lava cover of Góry Krucze (Awdankiewicz 1999a). Similar volcanoes in the central part of the Intra-Sudetic basin and in the North-Sudetic basin (Awdankiewicz 2006) erupted lavas mostly of an intermediate composition – trachyandesites and basaltic andesites, respectively. However, the most evolved rhyolitic magmas, in the eastern part of the Intra-Sudetic basin, erupted explosively with the formation of ca. 10 km diameter caldera and an extensive ignimbrite sheet i. e. the Góry Suche rhyolitic tuffs (Awdankie-wicz 1999a, 2004). The post-caldera activity included an intrusion of trachyandesitic and of rhyolitic sills and laccoliths along the caldera margins, and andesitic and rhyolitic eruptions. Another example of a silicic volcanic centre is to be found in the easternmost part of the North-Sudetic basin in the Wolbromek trough where volcanic products include rhyolitic tuffs, lavas and possibly extremely welded, lava-like ignimbrites (Pańczyk, Werner 2004).

The volcanic rocks are characterized by anhydrous phenocryst assemblages dominated by plagioclase, augite and olivine (subsequently altered) in the mafic rocks and alkali feldspars, quartz and minor biotite (some pseudomorphic after amphibole) in the felsic rocks (details in citations above). Low-Ca clinopyroxene (pigeonite) occurs in some trachyandesites of the Intra-Sudetic basin. Basaltic trachyandesites of the North-Sudetic basin are two-pyroxene (augite and enstatite) lavas. Post-magmatic alteration is common and its characteristic products include albite, sericite, quartz, carbonates, chlorites and clay minerals.

Geochemical variation The geochemical variation of the volcanic rocks is shown in Fig. 6. The TAS and Zr/TiO2-Nb/Y diagrams provide a basis for the classification of volcanic rocks. The lamprophyres and other hypabyssal rocks, classified on the basis of the petrographic criteria, are plotted for a comparison. In the TAS diagram the samples straddle the alkaline-subalkaline boundary and define two broad groups. Mafic rocks plot mainly in the fields of basaltic andesites, basaltic trachyandesites and trachyandesites whereas the felsic rocks fall within, and close to the rhyolite field. There is a significant compositional overlap of rocks from the volcanic and subvolcanic complexes though minettes and other lamprophyres tend to show higher alkali contents than the volcanic rocks of similar silica

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content. In addition, some scatter reflect alteration and mobility of silica and alkalis, e.g. some Carboniferous basaltic andesites in the Intra-Sudetic basin plot in the foidite field due to extensive replacement of silicates by carbonates.

Fig. 7A. Geochemical variation of the late Palaeozoic volcanic and subvolcanic rocks of Sudetes in the total alkalis-silica diagram (Le Maitre et al. 2004); for the symbol explanations see Fig. 7B.

The Zr/TiO2 vs. Nb/Y plot highlights distinctive clusters of analyses coming from the geographically and geologically related locations, i.e., from the bound magmatic systems. However, the mafic rocks show a strong variation of Nb/Y ratios, likely due to heterogeneity in their mantle sources. The normalized trace element patterns of mafic rocks (Fig. 7) point to a strong enrichment in the large-ion lithophile and light rare earth elements, especially in the lamprophyres. A characteristic feature of most of the mafic rocks, excepting some richterite minettes and basaltic trachyandesites, is a distinctive depletion in Nb, Ta and Ti. These features may indicate derivation of magmas from metasomatised mantle sources or assimilation of the continental crust. The normalized patterns of the felsic rocks (Fig. 7) typically indicate a strong enrichment, relative to Zr and Y, of such trace elements as Cs, Rb, Th, U, Nb, Ta, La, and Ce. However, there are also pronounced negative anomalies at Ba, Sr, P and Ti and also, in some samples, at La, Ce and Zr. Such anomalies may result from advanced fractional crystallization of feldspars, Fe-Ti oxides, La-Ce-bearing accessory minerals and zircon or partial melting of crustal rocks leaving residua containing these minerals.

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Fig. 7B. Geochemical variation of the late Palaeozoic volcanic and subvolcanic rocks of Sudetes in the Zr/TiO2 – Nb/Y plot (Winchester, Floyd 1977). Mafic volcanic rocks – basaltic andesites, andesites, basaltic trachyandesites, trachyandesites. Mafic subvolcanic rocks – lamprophyres, monzodiorites-micromonzodiorites. Felsic volcanic rocks – rhyodacites, rhyolites, rhyolitic tuffs. Felsic subvolcanic rocks – porphyrytic microgranites, aplites, rhyolites. Age: C – Carboniferous, P – Permian. Location: ISB – Intra-Sudetic basin, NSB – North-Sudetic basin, KIB – Karkonosze-Izera block, GSB – Góry Sowie block, OSD – Orlica-Śnieżnik dome, KZS – Kłodzko-Złoty Stok massif. Data used: 251 whole-rock analyses from Awdankiewcz 1999b, 2006 and unpublished. The diagrams were prepared by use of the GCDkit (Janoušek et al. 2006). ORIGIN AND DIFFERENTIATION OF MAGMAS The geological data show that several discrete magmatic systems, represented by individual subvolcanic complexes and volcanic centres, developed in the Sudetic area in Carboniferous to Permian times. The petrography and geochemistry further indicate that the magmas originated from various mantle sources and evolved along specific differentiation paths within each magmatic system. In general, the subvolcanic complexes involved more alkaline, hydrous magmas and the volcanic complexes less alkaline, volatile-poor magmas. The mafic rocks of these complexes may, in many cases, approximate to primitive mantle-derived melts and, also, to parental magma compositions for the more evolved rocks. The minettes, as the most primitive members of the subvolcanic complexes, probably originated from metasomatized or contaminated,

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Fig. 8. Primordial mantle-normalized (Wood et al. 1979) trace element patterns of late Palaeozoic volcanic and subvolcanic rocks in Sudetes.

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enriched mantle sources (Awdankiewicz 2007). The more differentiated mafic and felsic rocks generally represent the products of assimilation-fractional crystallization processes with variable influence of mixing between mantle and crustal melts (Awdankiewicz et al. 2005, Machowiak, Niemczyk 2005).

Enriched mantle sources were also involved in the formation of the basic-intermediate lavas emplaced within the intramontane troughs. In the Intra-Sudetic basin, the Carboniferous basaltic andesites show an active continental margin-like geochemical feature, interpreted as an “echo” of pre-Carbonifeous subduction processes whereas the Permian basaltic trachyandesites show more pronounced within-plate, intracontinental characteristics (Awdankiewicz 1999b). However, the geochemical characteristics of the Permian basaltic andesites of the North-Sudetic basin are transitional between extension-related, within-plate lavas and active continental margin lavas (Awdankiewicz 2006). Thus the geochemical types of mafic volcanic rocks varied both in time and space. The more evolved lavas, erupted within intramontane troughs, formed mainly due to fractional crystallization of the more primitive melts (Awdankiewicz 1999b, 2006) though the strong influence of crustal contamination processes has also been suggested (Dziedzic 1998). A general petrogenetic model, and several important aspects of the magmatic evolution of the subvolcanic and volcanic complexes of the Sudetes, remain to be refined by further studies and more detailed data, in particular on the isotope geochemical features and timing of the magmatic events.

FINAL REMARKS The Sudetic Variscan granites split into two distinct age groups dated at ca. 340-330 Ma and 320-300 Ma (see below). The emplacement age of the older granites, widespread in Central Sudetes and immediately south of the Odra fault zone (Fig. 3), corresponds to the main stage of nappe stacking within the Central European Variscides (e.g. Franke 2000). Thus, the increased supply of radiogenic heat into the thickened orogenic root may have caused a substantial temperature rise in the middle and lower crust and may have been a key factor contributing to generation of the Early Carboniferous granites. This suggestion is in good agreement with the P-T-t evolution of the metamorphic mantle rocks of granitoid plutons in Central Sudetes (Marheine et al. 2002) and with the formation of syn-kinematic migmatites, e. g., in the Orlica-Śnieżnik Massif (Fig. 3; see also Turniak et al. 2000). Thus, dehydratation melting may have occurred at mid-crustal levels due to Early Carboniferous thermal relaxation of overthickened Variscan crust without any significant heat input from the mantle (Gerdes et al. 2000).

A distinctly younger magmatic event, resulting in more voluminous granitic plutons, took place in Sudetes during Late Carboniferous time (320-300 Ma). Large, mostly peralumi-nous, granite bodies intruded into mostly cooled upper crust well after the climax of the Variscan orogeny. They are exemplified by the Karkonosze and Strzegom-Sobótka plutons (Fig. 3), the former bearing clear evidence for magma mixing (Słaby, Götze 2004). These plutons are locally accompanied by contemporaneous or slightly younger calc-alkaline granitoids with tonalite dykes or enclaves and by quartz-diorites (e.g., in the Strzelin massif, see Fig. 3). Pluton emplacement was synchronous with abundant mafic to felsic volcanism in the nearby intramontane troughs, i. e., in the Intra- and North-Sudetic basins. These features are evidence that the Late Carboniferous and Permian magmatism benefited from a significant input from primitive lithospheric mantle related to variably enriched or metasomatized mantle sources. This input can be explained by Late Carboniferous lithospheric extension that followed the cessation of the Variscan convergence (Henk 1997) or by delamination and convective removal of the thickened

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mantle lithosphere below the Bohemian massif (Finger et al. 2007). However, the interplay between tectonic and magmatic processes, and the proportions of various mantle and crustal sources involved in magma genesis, are still not well constrained in the complex post-orogenic setting of the Central European Variscides.

REFERENCES

Aleksandrowski P. 1990. Early Carboniferous strike-slip displacements at the northeast periphery of the Variscan belt in Central Europe. In: International Conference on Paleozoic Orogens in Central Europe (IGCP Program 233: Terranes in the Circum-Atlantic Paleozoic orogens), Abstracts, Göttingen-Giessen, 7-10.

Aleksandrowski P., Kryza R., Mazur S., Żaba J. 1997. Kinematic data on major Variscan strike-slip faults and shear zones in the Polish Sudetes, northeast Bohemian massif. Geological Magazine, 133, 727-739.

Aleksandrowski P., Mazur S. 2002. Collage tectonics in the northeasternmost part of the Variscan belt: the Sudetes, Bohemian massif. In: Palaeozoic amalgamation of Central Europe, eds. J. Winchester, T. Pharaoh, J. Verniers. Geol. Soc. London, Special Publication, 201, 237-277.

Anczkiewicz R., Szczepański J., Mazur S., Storey C., Crowley Q., Villa I. M., Thirlwall M. F., Jeffries T. E. 2007. Lu–Hf geochronology and trace element distribution in garnet: implications for uplift and exhumation of ultra-high pressure granulites in the Sudetes, SW Poland. Lithos, 95, 363-380.

Awdankiewicz M. 1999a. Volcanism in a late Variscan intramontane trough: Carboniferous and Permian volcanic centres of the Intra-Sudetic basin, SW Poland. Geologia Sudetica, 32, 13-47.

Awdankiewicz M. 1999b. Volcanism in a late Variscan intramontane trough: the petrology and geochemistry of the Carboniferous and Permian volcanic rocks of the Intra-Sudetic basin, SW Poland. Geologia Sudetica, 32, 83-111.

Awdankiewicz M. 2004. Sedimentation, volcanism and subvolcanic intrusions in a late Palaeozoic intramonatne trough (the Intra-Sudetic basin, SW Poland). In: Physical geology of high-level magmatic systems, ed. C. Breitkreuz, N. Petford. Geol. Soc. London, Special Publication, 234, 5-11

Awdankiewicz M. 2006. Fractional crystallization, mafic replenishment and assimilation in crustal magma chambers: geochemical constraints from the Permian post-collisional intermediate-composition volcanic suite of the North-Sudetic basin (SW Poland). Geologia Sudetica, 38, [in press].

Awdankiewicz M. 2007. Lamprophyres of the Orlica-Śnieżnik dome and the Kłodzko-Złoty Stok massif – new data on petrology, geochemistry and petrogenesis. Acta Musei Turnoviensis [in press].

Awdankiewicz M., Awdankiewicz H., Kryza R. 2004. Petrography and mineral chemistry of the Góry Sowie kersantites: preliminary results. Pol. Tow. Mineralog. Pr. Spec., 24, 65-68.

Awdankiewicz M., Awdankiewicz H., Kryza R. 2005. Petrology of mafic and felsic dykes from the eastern part of the Karkonosze massif. Pol. Tow. Mineralog. Pr. Spec., 26, 111-114.

Awdankiewicz M., Awdankiewicz H., Kryza R., Rodionov N. 2007. Preliminary SHRIMP zircon age of the micromonzodiorite from Bukowiec: age constraint for the Karkonosze granite (Polish Sudetes). Mineralogia Polon. Spec. Papers [submitted].

Bachliński R., Hałas S. 2002. K-Ar dating of biotite from the Kudowa Zdrój granitoids (Central Sudetes, SW Poland). Bull. Polish Acad. Sci., Earth Sciences, 50 (2), 113-116.

Badura J., Zuchiewicz W., Gorecki A., Sroka W., Przybylski B., Zyszkowska M. 2003. Morphotectonic properties of the Sudetic marginal fault, SW Poland. Acta Montana IRSM AS CR, Ser. A, 24 (131), 21-49.

Baranowski Z., Haydukiewicz A., Kryza R., Lorenc S., Muszyński A., Solecki A., Urbanek Z. 1990. Outline of the geology of the Góry Kaczawskie (Sudetes, Poland). N. Jb. Geol. Paläont., Abh., 179, 223-257.

Barbarin B. 1990. Granitoids: main petrogenetic classifications in relation to origin and tectonic setting. Geological Journ., 25, 227-238.

81

Barbarin B. 1999. A review of the relationships between granitoid types, their origins and their geodynamic environments. Lithos, 46, 605-625.

Bederke E. 1924. Das Devon in Schlesien und das Alter der Sudeten-faltung. Fortschr. Geol. Paläont., 7, 1-55.

Belka Z., Valverde-Vaquero P., Dörr W., Ahrendt H., Wemmer K. M., Franke W., Schäfer J. 2002. Accretion of first Gondwana-derived terranes at the margin of Baltica. In: Palaeozoic amalgamation of Central Europe, eds. J. A. Winchester, T. C. Pharaoh, J. Verniers, Geol. Soc. London, Special Publication 201, 19-36.

Białek D. 2003. Petrography and geochemistry of the Jawornickie granitoids, West Sudetes. Pol. Tow. Mineralog. Pr. Spec., 22, 22-24.

Białek D., Werner T. 2004. Geochemistry and geochronology of the Javornik granodiorite and its geodynamic significance in the Eastern Variscan belt. Geolines, 17, 22-23.

Borkowska M. 1966. Petrography of Karkonosze granite. Geologia Sudetica, 2, 7-119. Borkowska M., Hameurt J., Vidal P. 1980. Origin and age of Izera gneisses and Rumburk granites

in the Western Sudetes. Acta Geol. Polon., 30 (2), 121-145. Borucki J. 1966. K-Ar dating of Lower Silesian granitoids – preliminary results. Kwart. Geol., 10

(1), 1-19. Buschmann B., Nasdala L., Jonas P., Linnemann U. G., Gehmlich M. 2001. SHRIMP U-Pb dating

of tuff derived and detrital zircons from Cadomian marginal basin fragments (Neoproterozoic) in the northeastern Saxothuringian zone (Germany). N. Jb. Geol. Paläont., Mh., 6, 321-342.

Chlupáč I. 1993. Stratigraphic evaluation of some metamorphic units in the N part of the Bohemian massif. N. Jb. .Geol. .Paläont., Abh., 188, 363-388.

Chorowska M. 1978. Visean limestones in the metamorphic complex of the Kaczawa Mts (Sudetes). Ann. Soc. géol. Pologne, 48, 245-261.

Collins A. S., Kryza R., Zalasiewicz J. A. 2000. Macrofabric fingerprints of Late Devonian – Early Carboniferous subduction in the Polish Variscides, the Kaczawa complex, Sudetes. Journ. Geol. Soc., London, 157, 283-288.

Cymerman Z. 1996. The Złoty Stok – Trzebieszowice regional shear zone: the boundary of terranes in the Góry Złote Mts (Sudetes). Geol. Quart., 40, 89-118.

Cymerman Z., Piasecki M. A. J., Seston R. 1997. Terranes and terrane boundaries in the Sudetes, northeast Bohemian assif. Geological Magazine, 134, 717-725.

Depciuch T., Lis J. 1971. Absolute K-Ar age of granitoids from the Karkonosze massif. Kwart. Geol., 15 (4), 855-860.

Depciuch T., Lis J. 1972. Absolute age of K-Ar granitoids from Strzelin (Lower Silesia). Kwart. Geol., 16 (1), 95-102.

Dèzes P., Schmid S. M., Ziegler P. A. 2004. Evolution of the European Cenozoic rift system: interaction of the Pyrenean and Alpine orogens with the foreland lithosphere. Tectonophysics, 389, 1-33.

Domańska-Siuda J. 2006. Derivation and evolution of paternal magma for the hornblende-biotite granite from the western part of the Strzegom massif. Warsaw University Archives, 176 pp.

Dörr W., Żelaźniewicz A., Bylina P., Schastok J., Franke W., Haack U., Kulicki C. 2006. Tournaisian age of granitoids from the Odra fault zone (southwestern Poland): equivalent of the Mid-German crystalline high. Internat. Journ. Earth Sci., 95, 341-349.

Duthou J. L., Couturie J. P, Mierzejewski M. P., Pin C. 1991. Age determination of the Karkonosze granite using isochrone Rb-Sr whole rock method. Przegl. Geol., 2, 75-79.

Dziedzicowa H. 1963. “Syenites” of the Niemcza zone. Arch. Mineral., 24 (2), 5-109. Faure M., Leloix C., Roig J.-Y. 1997. L’évolution polycyclique de la chaîne hercynienne. Bull. Soc.

géol. .France, 168, 695-705. Finger F., Gerdes A., Janoušek V., Rene M., Riegler G. 2007. Resolving the Variscan evolution of

the Moldanubian sector of the Bohemian massif: the significance of the Bavarian and the Moravo-Moldanubian tectonometamorphic phases. Journ. Geosciences [in press].

Franke W. 2000. The mid-European segment of the Variscides: tectonostratigraphic units, terrane boundaries and plate tectonic evolution. In: Quantification and modelling in the Variscan belt eds. W. Franke, V. Haak, O. Oncken, D. Tanner. Geol. Soc. London, Special Publication 179, 35-61.

82

Franke W., Żelaźniewicz A. 2000. The eastern termination of the Variscides: terrane correlation and kinematic evolution. In: Quantification and Modelling in the Variscan belt eds. W. Franke, V. Haak, O. Oncken, D. Tanner. Geol. Soc. London, Special Publication, 179, 63-86.

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, 1035-1038.

Furnes H., Kryza R., Muszyński A., Pin C., Garmann L. B. 1994. Geochemical evidence for progressive, rift-related Early Paleozoic volcanism in the western Sudetes. Journ.. Geol. Soc. London, 151, 91-109.

Gerdes A. Wörner G., Henk A. 2000. Post-collisional granite generation and HT-LP metamorphism by radiogenic heating: the Variscan South Bohemian batholith. Journ. Geol. Soc. London, 157, 577-587.

Gunia T. 1984. Microfossils from the quartzitic schists in vicinity of Goszów, Śnieżnik Kłodzki massif, Central Sudetes. Geologia Sudetica, 18 (2), 47-57.

Gunia T. 1999. Microfossils from the high-grade metamorphic rocks of the Góry Sowie Mts. (Sudetes area) and their stratigraphic importance. Geol. Quart., 43 (4), 519-536.

Haydukiewicz J. 1990. Stratigraphy of Paleozoic rocks of the Góry Bardzkie and some remarks on their sedimentation. N. Jb. Geol. Paläont., Abh. 179, 275-284.

Henk A. 1997. Gravitational orogenic collapse vs plate boundary stresses: A numerical modelling approach to the Permo-Carboniferous evolution of Central Europe. Geol. Rundschau, 86, 39-55.

Hladil J., Mazur S., Galle A., Ebert J. 1999. Revised age of the Mały Bożków limestone in the Kłodzko metamorphic unit (Early Givetian, late Middle Devonian): implications for the geology of the Sudetes. N. Jb. Geol. Paläont., Abh. 211, 329-353.

Janeczek J. 1985. Typomorphic minerals from pegmatites of the Strzegom-Sobótka granitoid massif. Geologia Sudetica, 20 (2), 1-63.

Janoušek V., Farrow C. M., Erban V. 2006. Technical note. Interpretation of whole-rock geochemical data in igneous geochemistry: introducing geochemical data Toolkit (GCDkit). Journ. Petrology, 47, 1255-1259.

Kossmat F. 1927. Gliederung des varistischen Gebirgsbaues. Abh. Sächs. Geol. Landesamts, 1, 1-39.

Kröner A., Hegner E., Hammer J., Haase G., Bielicki K. H., Krauss M., Eidam J. 1994. Geochronology and Nd-Sr systematics of Lusatiann granitoids: significance for the evolution of the Variscan orogen in east-central Europe. Geol. Rundschau, 83, 375-376.

Kröner A., Štípská P., Schulmann K., Jaeckel P. 2000. Chronological constraints on the pre-Variscan evolution of the northeastern margin of the Bohemian massif, Czech Republic. In: Orogenic processes: quantification and modelling in the Variscan belt, eds. W. Franke, V. Haak, O. Oncken, D. Tanner. Geol. Soc. London, Special Publication 179, 175-197.

Kröner A., Jaeckel P., Hegner E., Opletal M. 2001. Single zircon ages and whole-rock Nd isotopic systematics of early Palaeozoic granitoid gneisses from the Czech and Polish Sudetes (Jizerské hory, Krkonoše and Orlice-Snĕžnik complex). Internat. Journ. Earth Sci., 90, 304-324.

Kryza R., Muszyński A., Vielzeuf D. 1990. Glaucophane-bearing assemblage overprinted by greenschist-facies metamorphism in the Variscan Kaczawa complex, Sudetes, Poland. Journ. Metamorph. Geol., 8, 345-355.

Kryza R., Mazur S. 1995. Contrasting metamorphic paths in the SE part of the Karkonosze-Izera block (Western Sudetes, SW Poland). N. Jb. Mineral., Abh., 169, 157-192.

Kryza R., Mazur S., Pin C. 1995. Leszczyniec meta-igneous complex in the eastern part of the Karkonosze-Izera block, Western Sudetes: trace element and Nd isotope study. N. Jb. Geol. Paläont., Abh., 170, 59-74.

Kryza R., Pin C., Vielzeuf D. 1996. High pressure granulites from the Sudetes (SW Poland): evidence of crustal subduction and collisional thickening in the Variscan belt. Journ. Metamorph. Geol., 14, 531–546.

Kryza R., Mazur S., Aleksandrowski P. 1999. Pre-Late Devonian unconformity in the Kłodzko area excavated: a record of Eo-Variscan metamorphism and exhumation in the Sudetes. Geologia Sudetica, 32,127-137.

83

Le Maitre R. W., Bateman P., Dudek A., Keller J., Lameyre J., Le Bas M. J., Sabine P. A., Schmid R., Sorensen H., Streickeisen A., Wooley A. R., Zanettin B. 2002. A classification of volcanic rocks and glossary of terms. Recommendations of the International Union of Geological Sciences Subcomission on the Systematics of Igneous Rocks. Blackwell, Oxford, 236 pp.

Linnemann U., Gehmlich M., Tichomirova 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. W. Franke, V. Haak, O. Oncken, D. Tanner. Geol. Soc. London, Special Publications, 179, 131-153.

Lorenc M. W. 1994. A role of mafic magmas in the evolution of granitoid intrusions (a compara-tive study from selected Hercynian massifs). Geologia Sudetica, 28, 1-130.

Lorenc M. W. 1996. Results of Rb-Sr analysis of the Niemcza granitoids. II Ogólnopolska Sesja Naukowa “Datowanie Minerałów i Skał” UMCS, Lublin, 24-25.10.1996, 40-44.

Machowiak K., Muszyński A., Armstrong R. 2004. High-level volcanic-granodioritic intrusions from Żelaźniak Hill (Kaczawa Mountains, Sudetes, SW Poland). In: Physical geology of high-level magmatic systems, eds. C. Breitkreuz, N. Petford. Geol. Soc. London, Special Publication, 234. 67-74.

Machowiak K., Niemczyk W. 2005. Subvolcanic rocks of the Żelaźniak intrusion (Kaczawa Mountains) compared with the Karkonosze granite. Przegl. Geol., 53, 51-55.

Machowiak K., Armstrong R. 2007. SHRIMP U-Pb zircon age of the Karkonosze granite. Mineral. Polon. – Special Papers. [submitted].

Majerowicz A. 1963. Granite from the vicinity of Sobótka and its relationship to the country rocks in the light of petrographic investigations. Arch. Mineral., 24 (2), 127-237.

Majerowicz A. 1972. Strzegom-Sobótka granitoid massif. Geologia Sudetica, 6, 7-96. Majerowicz A. 1981. Rock series of the Ślęża Mt. group in the light of petrologic studies of

ophiolite complex. In: Ophiolites and initialites of northern border of the Bohemian massif. Guidebook of Excursion 2, ed. W. Narębski. Potsdam-Freiberg, 172-179.

Marheine D., Kachlik V., Maluski H., Patočka F., Żelaźniewicz A. 2002. The 40Ar-39Ar ages from the West Sudetes (NE Bohemian massif): constraints on the Variscan polyphase tectonothemal development. In: Palaeozoic amalgamation of Central Europe, eds. J. Winchester, T. Pharaoh, J. Verniers. Geol. Soc. London, Special Publication, 201, 133-155.

Matte P., Maluski H., Reilich P., Franke W. 1990. Terrane boundaries in the Bohemian massif: results of large scale Variscan shearing. Tectonophysics, 177, 151-170.

Mattern F. 2001. Permo-Silesian movements between Baltica and western Europe: tectonics and “basin families”. Terra Nova, 13, 368-375.

Mazur S., Puziewicz J. 1995. Mylonites of the Niemcza zone. Ann. Soc. Geol. Polon., 64, 23-52. Mazur S., Kryza, R. 1996. Superimposed compressional and extensional tectonics in the

Karkonosze-Izera Block, NE Bohemian Massif. In: Basement tectonics 11, Europe and other regions, eds. O. Oncken, C. Janssen. Kluwer, Dordrecht, 51-66.

Mazur S., Aleksandrowski P. 2001. The Teplá(?) / Saxothuringian suture in the Karkonosze-Izera massif, Western Sudetes, Central European Variscides. Internat. Journ. Earth Sci., 90, 341-360.

Mazur S., Turniak K., Bröcker M. 2004. Neoproterozoic and Cambro-Ordovician magmatism in the Variscan Kłodzko metamorphic complex (West Sudetes, Poland): new insights from U/Pb zircon dating. Internat. Journ. Earth Sci., 93, 758-772.

Mazur S., Aleksandrowski P., Szczepanski J. 2005. The presumed Teplá-Barrandian / Moldanubian terrane boundary in the Orlica Mountains (Sudetes, Bohemian massif): structural and petrological characteristics. Lithos, 82 (1-2), 85-112.

Mazur S. Aleksandrowski P., Kryza R., Oberc-Dziedzic T. 2006. The Variscan orogen in Poland. Geol. Quart., 50 (1), 89-118.

Mikulski S. Z., Stein H. J. 2005. The Re-Os age for molybdenite from the Variscan Strzegom-Sobótka massif, SW Poland. In: Mineral deposit research: meeting the global challenge, eds. Jingwen Mao, F. P. Bierlein. Springer Verlag, Berlin- New York, 789-792.

Mikulski S. Z., Stein H. J., Markey R. J. 2005. Determination of sulfide ages from Lower Silesia using the Re-Os method. Pol. Tow. Mineralog. Prace Specjalne, 26, 217-220.

84

Muszyński A. 1987. Niektóre problemy petrograficzne lamprofirów sowiogórskich. Acta Univ. Wratisl. 788, Pr. Geol.-Mineral., 10, 137-156.

Muszyński A., Machowiak K., Kryza R., Armstrong R. 2002. SHRIMP U-Pb zircon geochronology of the late Variscan Żelaźniak rhyolite intrusion, Polish Sudetes – preliminary results. Polskie Pol. Tow. Mineralog. Prace Specjalne, 20, 156-158.

Oberc-Dziedzic T. 1998. The problem of tectonic setting evaluation for granitoids on an example of the Strzelin Hills granitoids (Fore-Sudetic block, SW Poland). Przegl. Geol., 46 (2), 147-154.

Oberc-Dziedzic T., Pin C., Duthou J. L., Couturie J. P. 1996. Age and origin of the Strzelin granitoids (Fore-Sudetic block, Poland): 87Rb/86Sr data. N. Jb. Mineral., Abh., 171 (2), 187-198.

Oberc-Dziedzic T., Żelaźniewicz A., Cwojdziński S. 1999. Granitoids of the Odra fault zone: late to post-orogenic Variscan intrusions in the Saxothuringian zone, SW Poland. Geologia Sudetica, 32, 55-71.

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. Internat. Journ. Earth Sci., 92, 701-711.

Oberc-Dziedzic T., Pin C., Kryza R. 2005. Geodynamic setting of the Early Palaeozoic granitoid magmatism in the Variscides: Sm-Nd constrains from the Izera granitogneisses (W Sudetes, SW Poland). Internat. Journ. Earth Sci., 94 (3), 354-368.

O'Brien P. J., Kröner A., Jaeckel P., Hegner E., Żelaźniewicz A., Kryza R. 1997. Petrological and isotopic studies on Palaeozoic high pressure granulites with a medium pressure overprint, Góry Sowie (Owl) Mts., Polish Sudetes. Journ. Petrology, 38, 433–456.

Oliver G. J. H., Corfu F., Krogh T. E. 1993. U-Pb ages from SW Poland: evidence for a Caledonian suture zone between Baltica and Gondwana. Journ. Geol. Soc. London, 150, 355-369.

Pańczyk M., Werner T. 2004. Preliminary results of anisotropy of magnetic suspectibility of the Permian volcanites from the Bolków area (north Sudetic basin). Pol. Tow. Mineralog. Prace Specjalne, 24, 311-314.

Parry M., Štípská P., Schulmann K., Hrouda F., Ježek J., Kröner A. 1997. Tonalite sill emplacement at an oblique plate boundary: northeastern margin of the Bohemian massif. Tectonophysics, 280, 61-81.

Patočka F., Valenta J. 1996. Geochemistry of the late Devonian intermediate to acid metavolcanic rocks from the southern part of the Vrbno group, the Jeseniky Mts. (Moravo-Silesian belt, Bohemian massif, Czech Republic): paleotectonic implications. Geolines, 4, 42-54.

Patočka F., Smulikowski W. 2000. Early Palaeozoic intracontinental rifting and incipient oceanic spreading in the Czech / Polish East Krkonoše / Karkonosze complex, West Sudetes (NE Bohemian massif). Geologia Sudetica, 33, 1-15.

Pietranik A., Koepke J., Puziewicz J. 2006. Crystallization and resorption in plutonic plagioclase: implications on the evolution of granodiorite magma (Gęsiniec granodiorite, Strzelin crystalline massif, SW Poland). Lithos, 86, 260-280.

Pin C., Vielzeuf D. 1983. Granulites and related rocks in Variscan median Europe: a dualistic interpretation. Tectonophysics, 93, 47-74.

Pin C., Puziewicz J., Duthou J. L. 1989. Ages and origins of a composite granitic massif in the Variscan belt: a Rb-Sr study of the Strzegom-Sobótka massif, W Sudetes (Poland). N. Jb. Mineral., Abh., 160 (1), 71-82.

Pupin J. P. 1985. Magmatic zoning of Hercynian granitoids in France based on zircon typology. Schweiz. Mineral. Petrogr. Mitt., 65, 29-56.

Pupin J. P., Turco G. 1972. Une typologie originale du zircon accesoire. Bull. Soc. Fr. Minéral. Cristallogr., 95, 348-359.

Puziewicz J. 1990. The Strzegom-Sobótka granite massif – current state of knowledge. Arch. Mineral., 46 (2), 95-141.

Puziewicz J. 1992. Origin of the Koźmice granodiorite (Niemcza zone, Lower Silesia). Arch. Mineral., 47 (2), 95-146.

Schulmann K., Gayer R. 2000. A model for a continental accretionary wedge developed by oblique collision: the NE Bohemian massif. Journ. Geol. Soc. London, 157, 401-416.

Seston R., Winchester J. A., Piasecki M. A. J. Crowley Q. G., Floyd P. A. 2000. A structural model for the western-central Sudetes: a deformed stack of Variscan thrust sheets. Journ.Geol. Soc. London, 157, 1155-1167.

85

Słaby E., Götze J. 2004. Feldspar crystallization under magma-mixing conditions shown by cathodoluminescence and geochemical modelling - a case study from the Karkonosze pluton (SW Poland). Mineralogical Magazine, 68 (4), 561–577.

Słaby E., Martin H. 2005. Mechanisms of differentiation of the Karkonosze granite. Pol. Tow. Mineral. Prace Specjalne, 26, 266-269.

Smulikowski W. 1995. Evidence for glaucophane-schist facies metamorphism in the East Karkonosze complex, West Sudetes, Poland. Geol. Rundschau, 84, 720-737.

Steltenpohl M. G., Cymerman Z., Krogh E. J., Kunk M. J. 1993. Exhumation of eclogitized continental basement during Variscan lithospheric delamination and gravitational collapse, Sudety Mountains, Poland. Geology, 21, 1111-1114.

Štipska P., Schulmann K., Thompson A. B., Ježek J., Kröner A. 2001. Thermo-mechanical role of a Cambro-Ordovician paleorift during the Variscan collision: the NE margin of the Bohemian massif. Tectonophysics, 332, 239-253.

Szczepański J. 2002. The 40Ar/39Ar cooling ages of white micas from the Jegłowa Beds (Strzelin massif, Fore-Sudetic block, SW Poland). Geologia Sudetica, 34, 1-7.

Tait J. A., Schätz M., Bachtadse V., Soffel H. 2000. Palaeomagnetism and Palaeozoic palaeogeography of Gondwana and European terranes. In: Orogenic processes: quantification and modelling in the Variscan belt, eds. W. Franke, V. Haak, O. Oncken, D. Tanner. Geol. Soc. London, Special Publication 179, 21-34.

Tikhomirova M. 2002. Zircon inheritance in diatexite granodiorites and its consequence on geochronology – a case study in Lusatia and the Erzgebirge (Saxo-Thuringia, eastern Germany. Chemical Geology, 191, 209-224.

Turnau E., Żelaźniewicz A., Franke W. 2002. Middle to early late Viséan onset of late orogenic sedimentation in the Intra-Sudetic Basin, West Sudetes: miospore evidence and tectonic implication. Geologia Sudetica v 34 p 9-16.

Turniak K., Mazur S., Wysoczanski R. 2000. SHRIMP zircon geochronology and geochemistry of the Orlica-Śnieżnik gneisses (Variscan belt of Central Europe) and their tectonic implications. Geodinamica Acta v 13 p 1-20.

Turniak K., Bröcker M. 2002. Age of two-mica granite from the Strzegom-Sobótka massif: new data from U/Pb monazite and xenotime study. Pol. Tow. Mineral. Prace Specjalne, 20, 211-213.

Turniak K., Tichomirowa M., Bombach K. 2005. Zircon Pb-evaporation ages of granitoids from the Strzegom-Sobótka massif (SW Poland). Pol. Tow. Mineral. Prace Specjalne, 25, 241-245.

Turniak K., Tichomirowa M., Bombach K. 2006. Pb-evaporation zircon ages of post-tectonic granitoids from the Strzelin Massif (SW Poland). Mineral. Polon. Special Papers, 29, 212-215.

Turniak K., Halas S., Wójtowicz A. 2007. New K-Ar cooling ages of granitoids from the Strzegom-Sobótka massif, SW Poland. Geochronometria, 27 [in press].

Wajsprych B. 1986. Sedimentary record of tectonic activity on a Devonian-Carboniferous continental margin, Sudetes. In: Regional Meeting, Excursion Guidebook IAS 7th, ed. A. K. Teisseyre. Ossolineum, Kraków – Wrocław, 141-64.

Wierzchołowski B. 1966. Bielice granitoids in the Sudetes and their country rocks. Arch. Mineral., 26 (1-2), 509-647.

Wierzchołowski B. 1976. Granitoids of the Kłodzko-Złoty Stok massif and their contact influence on the country rocks (petrographic characteristics). Geologia Sudetica, 11, 7-147.

Wierzchołowski B. 2000. Lamprophyres from Lądek Zdrój (Sudetes). Arch. Mineral., 53, 85-108. Winchester J. A., Floyd P. A. 1977. Geochemical discrimination of different magma series and

their differentiation products using immobile elements. Chemical Geology, 20, 325-343. Winchester J. A., Floyd P. A., Chocyk M., Horbowy K., Kozdrój W. 1995. Geochemistry and

tectonic environment of Ordovician meta-igneous rocks in the Rudawy Janowickie complex, SW Poland. Journ. Geol. Soc. London, 152, 105-115.

Winchester J. A. & PACE TMR Network Team 2002. Palaeozoic amalgamation of Central Europe: new results from recent geological and geophysical investigations. Tectonophysics, 360, 5-21.

Wojciechowska I. 1975. Tectonics of the Kłodzko-Złoty Stok granitoid massif and its country rocks in the light of the mesostructural investigation. Geologia Sudetica, 10, 61-121.

86

Wood D. A., Joron J. L., Treuil M., Norry M., Tarney J. 1979. Elemental and Sr isotope variations in basic lavas from Iceland and the surrounding ocean floor. Contrib. Mineral. Petr., 70, 319-339.

Ziegler P. A. 1990. Geological atlas of Western and Central Europe. 2nd edition. Shell Intrnationale Maatschappij B.V. /Geological Society Publishing House, Bath, 239 pp.

Authors’ addresses: Stanisław Mazur Institute of Geological Sciences, Faculty of Earth Science and Environmental Management, Wrocław University, ul. Kuźnicza 35, 50-138 Wrocław, Poland; e-mail: smazur@ing.uni.wroc.pl Paweł Aleksandrowski Institute of Geological Sciences, Faculty of Earth Science and Environmental Management, Wrocław University, ul. Kuźnicza 35, 50-138 Wrocław, Poland; e-mail: palex@ing.uni.wroc.pl Krzysztof Turniak Institute of Geological Sciences, Faculty of Earth Science and Environmental Management, Wrocław University, ul. Kuźnicza 35, 50-138 Wrocław, Poland; e-mail: ktur@ing.uni.wroc.pl Marek Awdankiewicz Institute of Geological Sciences, Faculty of Earth Science and Environmental Management, Wrocław University, ul. Kuźnicza 35, 50-138 Wrocław, Poland; e-mail: mawdan@ing.uni.wroc.pl

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