A new exposure of a caldera fault segment at the Slieve Gullion Igneous Centre: implications for the emplacement of the early ring-complex

Troll, V., Meade, F.C., Chew, D.M. and Emeleus, C.H. (2008) A new exposure of a caldera fault segment at the Slieve Gullion Igneous Centre: implications for the emplacement of the early ring-complex. Irish Journal of Earth Sciences, 26, pp. 1-16.

Abstract

A contact zone between porphyritic microgranite of the early ring-complex of the Paleocene Slieve Gullion igneous centre and Lower Palaeozoic metasedimentary rocks of the Longford–Down inlier was exposed along a 300m section excavated during construction of the new M1 motorway. The outcrop displays a thin sliver of Longford–Down metasediment in contact with porphyritic microgranite in a steep, and locally intensely crushed, contact zone that dips away from the ring-complex. This outcrop pattern is reminiscent of a 'caldera-superfault'. Given the recent discussion on sheet versus ring-dyke emplacement of the early ring-complex at Slieve Gullion, this new evidence argues in favour of the traditional ring-dyke model with magma ascending along an active ring fracture associated with caldera subsidence.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Meade, Dr Fiona
• Authors: Troll, V., Meade, F.C., Chew, D.M., and Emeleus, C.H.
• Subjects: Q Science > QE Geology
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Irish Journal of Earth Sciences
• ISSN: 0790-1763
• ISSN (Online): 2009-0064
• Published Online: 01 January 2008