Central Highlands (Grampian) Terrane - metamorphic basement, Northern Ireland

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Mitchell, W I (ed.). 2004. The geology of Northern Ireland-our natural foundation. Geological Survey of Northern Ireland, Belfast.

M R Cooper and T P Johnston

Introduction

The Mesoproterozoic and Neoproterozoic metamorphic basement in Northern Ireland consists of deformed and metamorphosed sedimentary and volcanic rocks. Their distribution here is viewed as a continuation of similar lithologies and stratigraphical sequences in Scotland and northwest Ireland [1]. In Scotland the southern boundary of this terrane is the Highland Boundary Fault. In Northern Ireland geophysical evidence indicates that the Fair Head-Clew Bay Line (Chapter 1) and (Chapter 19) is the southwesterly continuation of that fault although basement rocks do occur south of that line in the Central Inlier of Co. Tyrone[2]. The rocks are divided into a Pre-Dalradian Basement and the Dalradian Supergroup.

Introduction

Pre-Dalradian basement
Lough Derg Inlier (Lough Derg Group: Slishwood Division)
Central Inlier (Corvanaghan Formation)

Dalradian Supergroup

Stratigraphy
Argyll Group
Sperrin Mountains
Southern Highland Group
South Sperrin Mountains
North Sperrin Mountains and North Co. Londonderry
West Co. Tyrone
Northeast Co. Antrim

Deformation of the Dalradian Regional metamorphism

References

  1. Hutton, D H W. 1987. Strike-slip terranes and a model for the evolution of the British and Irish Caledonides. Geological Magazine. 125, 405–25.
  2. Bluck, B J, Gibbons, W, and Ingham, J K. 1992. Terranes. In: Cope, J C W, Ingham, J K, and Rawson, P F (eds.). Atlas of Palaeogeography and Lithofacies. Geological Society of London, Memoirs, 13, 1–4.