Palaeogene Alpine tectonics and Icelandic plume-related magmatism and deformation in Northern Ireland

• Published in: Journal of the Geological Society Vol. 169; no. 1; pp. 29 - 36
• Main Authors: Cooper, M. R, Anderson, Hugh, Walsh, J. J, Van Dam, C. L, Young, M. E, Earls, G, Walker, A
• Format: Journal Article
• Language: English
• Published: London, UK Geological Society of London 01.01.2012; The Geological Society of London; Geological Society; Geological Society Publishing House
• Subjects: airborne methods; Alpine Orogeny; Caledonian Orogeny; Carboniferous; Cenozoic; Colleges & universities; compression tectonics; conjugate faults; Crystalline rocks; deformation; digital terrain models; dike swarms; displacements; Earth sciences; Earth, ocean, space; Europe; Exact sciences and technology; extension; faults; Geology; geophysical surveys; Iceland Plume; igneous and metamorphic rocks; Igneous and metamorphic rocks petrology, volcanic processes, magmas; magmatism; magnetic anomalies; mantle plumes; Northern Ireland; orogeny; Paleogene; Paleozoic; Petrology; Plate tectonics; reactivation; Rural areas; Rural development; strike-slip faults; Structural geology; surveys; tectonics; Tertiary; United Kingdom; University colleges; volcanism; Western Europe; United Kingdom; North Atlantic; Northern Ireland; Atlantic Ocean; Europe; Western Europe; AN, North Atlantic; ANE, British Isles, Northern Ireland; ANE, Europe; stress; extension; swarms; plumes; strike-slip; Carboniferous; surveys; Paleozoic; strike-slip faults; magmatism; upper Paleozoic; uplifts; displacements; deformation; mantle; tectonics; Phanerozoic; compression; Cenozoic; high resolution
• ISSN: 0016-7649; 2041-479X
• DOI: 10.1144/0016-76492010-182

The Cenozoic tectonic history of NW Europe is generally attributed to some combination of three principal controlling factors: North Atlantic opening, Alpine collision and formation of the Icelandic mantle plume. Using constraints from the high-resolution Tellus aeromagnetic survey of Northern Ireland, we show that Palaeogene tectonics can be attributed to approximately north-south Alpine-related compression, forming NNW-SSE-trending dextral and ENE-WSW-trending sinistral conjugate strike-slip faults, with the latter defined by kilometre-scale displacements along reactivated Caledonian or Carboniferous faults. This tectonism was, however, punctuated by pulsed magmatic intrusive and extrusive events, including four distinct dyke swarms that are attributed to NE-SW- to east-west-directed plume-related extension. Although this evidence shows, for the first time, that north-south Alpine compression was periodically overwhelmed by the dynamic stresses and uplift associated with pulsed mantle plume-related deformation, associated strike-slip faulting may have controlled the locus of volcanic activity and central igneous complexes, and the location of sedimentary depocentres.