A structural profile of Caledonian deformation in Down

Abstract

Coastal exposure in County Down provides an almost complete cross section of the continuation of the Southern Uplands fold belt in Ireland. Intensely folded Ordovician and Silurian turbidite successions are segmented by at least ten major strike parallel faults. In each segment the fold envelope descends northward but the strike faults throw up progressively younger sediments to the south. A system of upright folds, with slaty cleavage axial plane, but locally transecting, becomes progressively complicated southward by the clear development of two further phases of folding.and cleavage with constant geometry and opposing vergence. The chronology of cleavage, folding, later kink-band and brittle deformation is punctuated by successive late Caledonian lamprophyre dyke swarms. The total structure is consistent with a model of diachronous deformation and northward translation and rotation at a destructive plate margin.

Sedimentology, volcanism, structure and metamorphism of the northern margin of a Lower Palaeozoic accretionary complex; Bail Hill-Abington area of the Southern Uplands of Scotland

“…defined in any one block are not necessarily contemporaneous. South-easterly vergence of early fold phases across the Southern Uplands is consistent with underthrusting towards the NW (Anderson & Cameron 1979). This uniformity of fold vergence direction is seen in modern accretionary complexes, and is dominantly oceanward (J. C. Moore & Karig 1976).…”

Late Caledonian dyke‐swarms in Southern Scotland: New field, petrological and geochemical data for the Wigtown Peninsula, Galloway

“…Although bedding in the country rocks is predominantly northward younging, palaeontological evidence proves that the strata become progressively younger Anderson and Cameron 1979). The conjugate D, folds require a NW-SE principal shortening direction in the plane of bedding, and are consistent with deformation in a similar stress regime to that which formed D,.…”

“…Subsequent, predominantly structural studies (e.g. Rust 1965;Weir 1968;Anderson and Cameron 1979) confirmed these observations and showed that some dykes were involved in folding and faulting. However, none of these papers provided chemical or modern petrographical data.…”

“…Weir 1968;Anderson and Cameron 1979) precedes D2 folding. This deformation, as argued earlier, must have been closely related to D, and to thrusting, and therefore dyke emplacement was contemporaneous with the later stages of thrusting.…”

The nature and regional significance of structures in the Gala Group of the Southern Uplands terrane, Berwickshire coast, southeastern Scotland

“…Numerous studies have documented the structures present in this terrane in some detail, notably in Northern Ireland (e.g. Anderson & Cameron, 1979;Anderson & Oliver, 1986;Anderson, 1987), southwestern Scotland (e.g. Stringer & Treagus, 1980, 1981Anderson & Oliver, 1986;Kemp, 1986Kemp, , 1987Barnes, Anderson & McCurry, 1987;Stone, 1995Stone, , 1996Lintern & Floyd, 2000) and inland regions of the Southern Uplands (e.g.…”