Affiliation:
1. Dublin Institute for Advanced Studies, 5 Merrion Square, Dublin 2, Ireland (e-mail:pr@cp.dias.ie)
2. Department of Geology, University College Dublin, Belfield, Dublin 4, Ireland
Abstract
Marine gravity and magnetic surveys around Ireland, together with satellite gravity data from the deeper ocean, are used to investigate the large-scale crustal structure of the Porcupine Basin, offshore west of Ireland. The structure of the syn-rift to post-rift sedimentary successions, derived from vertical incidence seismic reflection data, is used to isolate the gravity and magnetic responses of the crust and mantle. The crustal structure derived from wide-angle seismic data in the region is used to control the interpretation and modelling. The results of gravity modelling in the southern part of the Porcupine Basin suggest a crustal thickening in the centre of the basin. Comparison with the Rockall Basin, where axial crustal thickening is seismically defined, suggests a similar pattern of crustal extension. The amount of extension is less across the narrower northern sector of the Porcupine Basin, where a north–south-trending axial gravity high is present resulting from anomalous density variations in the lower crust/upper mantle. A new model for the large-scale structural development of the Porcupine Basin is presented that explains the along-axis variations in crustal structure in terms of changes in the kinematics of crustal extension across NW–SE transfer zones. This model involves tectonic unroofing of the mantle lithosphere and serpentinization of the exhumed mantle peridotites.
Publisher
Geological Society of London
Subject
Fuel Technology,Energy Engineering and Power Technology,Geology,Geochemistry and Petrology
Reference37 articles.
1. The relationship between seismic velocity and density in the continental crust ? a useful constraint?
2. Bentley P. A. D. Scrutton R. A. 1987. Seismic investigations into the basement structure of the southern Rockall Trough. In: Brooks J. Glennie K. W. (eds) Petroleum Geology of North West Europe. Graham & Trotman, London, 667–675.
3. Gravity and magnetic studies of crustal structure across the Porcupine basin west of Ireland
4. The structural and stratigraphic framework of the Irish Rockall Trough
5. The Clare Basin: a geological and geophysical outline;Croker;The Petroleum Geology of Ireland’s Offshore Basins,1995
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