The deep geology and geophysics of Ireland and its continental margin

Abstract

A two day meeting on 28th and 29rh October 1989 attracted an international audience of over 90 scientists principally from academic institutions and the oil and minerals industries to hear 24 papers on the deep geology and geophysics of Ireland and its continental margin. The aim of the meeting was to present and discuss the results of a number of recent geophysical experiments and to relate them to models of the deep geology Gravity and magnetic data for Ireland were reviewed by Murphy (Dublin Institute for Advanced Studies) whilst Lowe, Jacob, Prodehl and Ruthardt (Dublin Institute for Advanced Studies and University of Karslruhe gave an account of two land seismic refraction experiments across and parallel to Caledonian trends (COOLE and ICCSP). They demonstrated that the Moho beneath Ireland lies at a depth of about 30 km, and a clear change of velocity structure occurs across the Iapetus suture zone. Two magnetotelluric experiments were described by Brown & Whelan (University College Galway) and by Meju (University of Leicester). Both indicated zones of anomalously high crustal conductivity, the most prominent of which is associated with the Iapetus suture zone. A petrological model for such zones involving free water in the lower crust was described by Sanders (Trinity College Dublin; this volume). Ford, Brown & Readman (Plymouth Polytechnic, University College Galway and Dublin Institute for Advanced Studies; this volume) used gravity data from southwest Ireland to elucidate basement structures in the Variscides. Offshore potential field data were described by Readman, Gohl, Liebe & Makris