Evidence for 1.82 Ga transpressive shearing in a 1.85 Ga granitoid in central Sweden: implications for the regional evolution

Migmatization related to mafic underplating and intra- or back-arc spreading above a subduction boundary in a 2.0–1.8 Ga accretionary orogen, Sweden

“…These boundary shear belts are composed of a collage of spatially more restricted, steeply dipping ductile shear zones with WNW-ENE to NW-SE or NNW-SSE strike, showing combined dextral strike-slip and dip-slip kinematics which is commonly transpressive in character. The structures show multiphase reactivation in different tectonic regimes, deformation along the Hassela Shear Zone, for example, initiating around 1.86 Ga and with continued ductile strain around 1.82 Ga (Högdahl and Sjöström, 2001;Högdahl et al, 2012).…”

“…The northern boundaries of the Ljusdal, Bergslagen and Små-land lithotectonic units are located along the Hassela Shear Zone (Högdahl and Sjöström, 2001;Högdahl et al, 2012); the Hagsta Gneiss Zone (Högdahl et al, 2009) and Storsjön-Edsbyn Deformation Zone (Bergman et al, 2006b); and the Loftahammar-Linköping Deformation Zone (Stephens et al, 1997;Beunk and Page, 2001;Wik et al, 2005), respectively ( Fig. 2A).…”

“…12). The older metamorphic event was accompanied by synmigmatite ductile shearing while the stromatic migmatite formed at 1.83-1.82 Ga was affected by folding and later ductile shearing (Högdahl and Sjöström, 2001;Högdahl et al, 2008Högdahl et al, , 2012Wik et al, 2009).…”

Trans-Baltic Palaeoproterozoic correlations towards the reconstruction of supercontinent Columbia/Nuna

“…Seismically, Bergslagen has also been traced in the middle and lower crust beneath the Ljusdal domain farther north (Korja and Heikkinen, 2005). Andersson (1997), Andersson et al (2004), Bergman et al (2008), Beunk and Page (2001), Hermansson et al (2007Hermansson et al ( , 2008, Högdahl and Sjöström (2001), Högdahl et al (2004), Johansson et al (2006, Krzeminska et al (2009), Lahtinen andNironen (2010), Lahtinen et al (2002Lahtinen et al ( , 2009a, Mansfeld et al (2005), Rutland et al (2001Rutland et al ( , 2004, Stephens et al (2009), Sultan et al (2005, Wikström and Andersson (2004), Williams et al (2008Williams et al ( , 2009). Fe-S-Si indicates the presence of various iron-and sulfide ore deposits.…”

1.8 Ga magmatism in southern Finland: strongly enriched mantle and juvenile crustal sources in a post-collisional setting

“…86 Ga from juvenile sources in volcanic arcs and intervening sedimentary basins, which were accreted to the Archaean cratonic nucleus from the present southerly direction (Gaál and Gorbatschev 1987;Nironen 1997). According to recent geodynamic models, the Downloaded by [McGill University Library] Högdahl and Sjöström 2001). The Palaeoproterozoic Arc Complexes under concern in Finland (e.g.…”