About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

CSPG Special Publications

Abstract


Geology of the North Atlantic Borderlands — Memoir 7, 1981
Pages 683-725
European Borderlands

The Late Paleozoic Evolution of Southern Ireland in the Context of Tectonic Basins and Their Transatlantic Significance

P. R. R. Gardiner, I. A. J. MacCarthy

Abstract

The Upper Paleozoic succession in southern Ireland ranges from Lower Devonian to Upper Carboniferous, with a total thickness in excess of 8 km. Eight major successive time intervals are recognized and depicted on paleogeographic maps. Deposition was concentrated in a northerly Dingle-Shannon Basin and a southerly Munster Basin, flanked by thinner platform sequences. The Dingle-Shannon Basin was initiated in the Early Devonian, when thick continental deposits accumulated at its western end; subsequently it underwent pre-Late Devonian (Acadian) deformation. Following localized differential movement along its southern margin in ?early Late Devonian times, the Basin remained relatively stable until the Namurian. It then became reactivated and subsequently infilled by a thick deltaic wedge prograding to the southeast. The Munster Basin developed as a post-orogenic depositional site before the Late Devonian, the thick continental infill reflecting an intercratonic setting. Marine breaching from the southeast was effected in the late Late Devonian and subsequent localized delta development was repeatedly interrupted by northerly directed transgressive pulses. During the Early Carboniferous, terrigenous sediments were replaced by carbonates which blanketed both basins. The Namurian clastic infilling of the Dingle-Shannon Basin spread progressively southwards into the Munster Basin and by Westphalian times widespread paralic conditions were established.

Analysis of the structural framework indicates that deposition was repeatedly influenced by movement along major inherited lineaments. Trans-Atlantic correlation suggests that one of these lineaments, the Wexford Boundary Lineament off the south coast of Ireland, may be the European analogue to the Hermitage-Dover Fault Line. Comparison of the Fundy and southwest Newfoundland Basin sequences with those of southern Ireland shows a number of gross features in common, including (1) Sequences deformed by the Acadian Orogeny, (2) Basin subsidence in the Late Devonian, (3) Rejuvenation of clastic source areas and marine regression in Late Visean-Early Namurian times, (4) Progressive basin filling in the Namurian and the subsequent establishment of widespread coaliferous facies in the Westphalian, albeit limnic in Canada and paralic in southern Ireland. These similarities accord with the concept of a laterally similar position on the same craton for the Canadian Basins and the southern Ireland Basins during the Late Paleozoic.


Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24