Author's Personal Copy

Author's personal copy

Gondwana Research 25 (2014) 649–667

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Gondwana Research

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Recurrent high grade metamorphism recording a 300 Ma long Proterozoic crustal evolution in the western part of the East European Craton

Grazina Skridlaite a,⁎, Svetlana Bogdanova b, Ludmila Taran c, Boguslaw Baginski d a Institute of Geology and Geography, Nature Research Centre, Vilnius, Lithuania b Department of Geology, Lund University, Sweden c Belarussian Research Geological Exploration Institute, Minsk, Belarus d Faculty of Geology, Warsaw University, Poland article info abstract

Article history: The Palaeoproterozoic lower crust, forming several belts and domains, is a major component of the crystal- Received 1 May 2012 line basement within the large region to the southeast of the Baltic Sea in Belarus, Lithuania and Poland. Received in revised form 17 April 2013 Four stages of high grade metamorphism have been determined in the Western Lithuanian Granulite domain Accepted 17 April 2013 (WLG) and Belarus–Podlasie Granulite belt (BPG), the western East European Craton (EEC). We have carried Available online 14 May 2013 out P–T studies, secondary ion mass-spectrometry (SIMS) zircon- and electron probe (EPMA) — monazite dating of peak metamorphism. The ﬁrst stage occurred at 1.81–1.79 Ga under 800–900 °C and 8–10 kbar Keywords: East European Craton and was related to both accretionary and postcollisional tectonics in the South Baltic region, whereas the P–T–t paths stages at 1.73–1.68 Ga (700–800 °C, 6–7 kbar), 1.62–1.58 Ga (700 °C, 4–5 kbar), and 1.52–1.50 Ga (900 °C, Granulites c. 10 kbar) can be attributed to extensional intracratonic regimes. The 1.81–1.79 Ga stage was connected SIMS and EPMA dating both to the major Sarmatia–Fennoscandia collision and the eastward accretion, which led to the formation of Baltica (East-European Craton) during the assembly of the Columbia (Nuna) supercontinent. The later high grade events associated with intracratonic extensions and magmatism may be distal manifestations of accretionary processes along the long-lived common Laurentia–Baltica margin. The 1.52–1.50 Ga metamorphism was associated with extensive anorthosite–mangerite–charnockite–granite magmatism in already consolidated crust. © 2013 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

1. Introduction High grade rocks feature at large scale in the region to the east and south of the Baltic Sea (hereafter the South Baltic belts or SBB), where Granulites and other high temperature rocks are important indica- the crystalline crust is covered by platformal sedimentary rocks reaching tors of major geodynamic processes in both compressional and exten- thickness of more than 2 km (Fig. 1). These rocks have been recovered by sional regimes and also helpful tools for tectonic reconstructions since hundreds of drillings and recognized by particular magnetic anomaly pat- they can be generated in various tectonic settings (Harley, 1989). Re- terns (e.g. Aksamentova and Naydenkov, 1990; Bogdanova et al., 2006). cent petrological–thermomechanical modeling of geodynamic regimes High grade rocks form distinct large belts extending for more than at active continental margins (Sizova et al., 2010; Gerya and Meilick, 1000 km, like the Belarus–Podlasie granulite belt (BPG) together with 2011) suggests several scenarios in which granulites can be created, the South Estonian and Latvian granulite blocks, or separate blocks such and their characteristics may provide insight into lithosphere evolution as the 150 × 150 km West Lithuanian Granulite domain (WLG, Fig. 1). (Brown, 2007). This is in contrast to the Baltic Shield in Sweden and southern Finland The western part of the East European Craton or “Baltica” in the where Proterozoic granulites are exposed over relatively small areas Palaeo- and Mesoproterozoic was a branch of the Laurentia–Baltica (e.g. Väasänen et al., 2000; Andersson et al., 2006). It is notable that SBB margin, which was active from c. 1.8 Ga to 1.0 Ga, that is encompassing granulites are spatially associated with c. 1.90–1.50 Ga plutonic com- the period from the assembly and break-up of the supercontinent plexes (Bibikova et al., 1995; Rämö et al., 1996; Claesson et al., 2001; Columbia/Nuna until the consolidation of Rodinia (Karlstrom et al., Rimsa et al., 2001; Motuza et al., 2006; Soesoo et al., 2006; Skridlaitė 2001; Rogers and Santosh, 2002; Bogdanova et al., 2008). et al., 2007; Motuza et al., 2008; Skridlaite et al., 2008; Vejelyte, 2011), and thus record the c. 300 Ma long tectonothermal history of the western EEC. The conditions of high grade metamorphism were summarized in Bogdanova et al. (2006), Skridlaite and Motuza (2001), Skridlaite et al. ⁎ Corresponding author. Tel.: +370 5 2104710; fax: +370 5 2104695. E-mail addresses: [email protected] (G. Skridlaite), [email protected] (2003b) and Taran and Bogdanova (2001); however except for a few (S. Bogdanova), [email protected] (L. Taran), [email protected] (B. Baginski). cases (cf. Claesson et al., 2001; Skridlaite et al., 2010), the ages of the