The South Connemara Group reinterpreted: a subduction-accretion complex in the Caledonides of Galway Bay, western Ireland

The Neoproterozoic to Mid-Devonian evolution of Scotland: a review and unresolved issues

“…By analogy with western Ireland and Newfoundland, the arc faced and collided with the Laurentian margin during the early Ordovician (Dewey 2005) but, unlike Newfoundland, its forearc ophiolites did not obduct very far, if at all, on to the rifted margin. Rather, we suggest, the arc bulldozed the Laurentian margin to cause the Grampian Orogeny, a very short-lived event followed by subduction polarity flip to initiate a trench on the south side of the South Connemara/ Southern Uplands accretionary prism (Ryan & Dewey 2004). Although the Midland Valley and the South Mayo Trough appear to be parts of the same terrane (Fig.…”

“…The general model (Dewey 1969;Dewey & Shackleton 1984) for the evolution of the northern Appalachians and the Scottish and Irish orthotectonic Caledonides involves the collision of the Laurentian rifted margin with an oceanic-arc system and other terranes; and the obduction of forearc ophiolites (Dewey & Casey 2011, the Bay of Islands and Shetland Ophiolite Complexes on to the rifted margin, followed by a flip in subduction polarity (Nelson & Casey 1979) and the development of a south-facing arc and accretionary prism (Southern Uplands and South Connemara; Ryan & Dewey 2004;Dewey 2005). The supposed line or zone of arc-continent collision runs from South Achill and Clew Bay ('Clew Bay Suture') in western Ireland , through Co. Tyrone, and along the Highland Boundary Fault to Shetland (Fig.…”

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

“…14C and 14D). While the northern part of the Laurentian margin in Greenland was undergoing limited magmatism and tectonic quiescence, the central part of the Laurentian margin at the latitude of the Canadian Appalachians was experiencing continental extension and multiple episodes of backarc basin formation, leading to the generation of microcontinents and subsequent collisional events (arc-continent, continent-continent) (e.g., Ryan and Dewey, 2004;Zagorevski et al, 2009;van Staal et al, 2009;Zagorevski and van Staal, 2011).…”

Evidence for seamount accretion to a peri-Laurentian arc during closure of Iapetus 1This article is one of a series of papers published in CJES Special Issue: In honour of Ward Neale on the theme of Appalachian and Grenvillian geology.2 Geological Survey of Canada Contribution 20100465.

“…van Staal et al (1998) proposed that the South Connemara Group and Southern Uplands in Scotland represent the extension of the Annieopsquotch Accretionary tract in the British Isles. The South Connemara Group (e.g., Ryan and Dewey 2004) and Southern Uplands (e.g., Waldron et al 2008) lie north of inferred suture and contain sedimentary rocks interpreted as trench fill with fragments of seamounts. These collectively constitute an accretionary complex that formed outboard of the composite Laurentian margin, prior to the closure of Iapetus and the arrival of peri-Gondwanan crust.…”

“…In the British Isles, the emergent, rapidly exhuming Grampian orogen (e.g., Ryan and Dewey 2004;Waldron et al 2008) provided abundant Fig. 7.…”