Structure, geochemistry, and tectonic evolution of trench-distal backarc oceanic crust in the western Norwegian Caledonides, Solund-Stavfjord ophiolite (Norway)

A plate tectonic scenario for the Iapetus and Rheic oceans

“…Such a scenario could also explain the Early Ordovician HP complexes presently preserved in western Svalbard, as well as the timing of subduction initiation beneath northeast Greenland-Svalbard in the Middle Ordovician. Accordingly, the appearance of Late Ordovician to early Silurian subduction-related magmatism in the Köli nappe complex (Meyer et al, 2003;Corfu et al, 2014) and the genesis of coeval suprasubduction zone ophiolitic rocks in the Solund-Stavfjord nappe (Furnes et al, 2012) can be related to west-dipping subduction beneath northeast Laurentia, following accretion of the intraoceanic arc to the margin of Laurentia and a consequent reversal in the polarity of subduction. This scenario is further corroborated by the metasedimentary assemblages of Laurentian affinity that structurally overlie the oceanic complexes in the Caledonide nappe stack, which were variably deformed and metamorphosed during the Ordovician, and intruded by Ordovician to Silurian magmatic arc rocks (Barnes et al, 2007;Roberts et al, 2007;Corfu et al, 2014).…”

Tectonometamorphic evolution of the Åreskutan Nappe – Caledonian history revealed by SIMS U–Pb zircon geochronology

“…Deposition in the foreland basin continued through the Silurian and thrusting into the Early Devonian, being related to advance of the Caledonian nappes. In the Upper Allochthon, overlying the Seve Nappe Complex, Scandian collision may be defined by the emplacement of the youngest oceanic crust (Solund-Stavfjord ophiolite, c. 443 Ma; Pedersen & Dunning 1993;Furnes et al 2012) in the earliest Silurian. Widespread calc-alkaline arc-and back-arc-related magmatism Pedersen et al 1991;Corfu et al 2006) accompanied this initial collision during the earliest Llandovery (443-437 Ma).…”

From Large Zones to Small Terranes to Detailed Reconstruction of an Early to Middle Ordovician Arc–Backarc System Preserved Along the Iapetus Suture Zone: A Legacy of Hank Williams

“…The spreading centre may have been oblique to the composite Laurentian margin or may have propagated into a promontory situated along it Cutts et al 2012). The relationship between an ophiolitic spreading centre and continental crust is rarely documented in ancient ophiolite belts (see de Wit and Stern 1981;van Staal et al 1996;Furnes et al 2012;Hollis et al 2012Hollis et al , 2013 for exceptions); however, there is some similarity to the IzuBonin -Mariana arc, where Cretaceous basement was transected during Eocene subduction initiation-related spreading (Ishizuka et al 2011). …”