Electrical conductivity distribution of the lithosphere in Ireland revealed by magnetotelluric imaging
Abstract
The present day lithospheric structure beneath Ireland is largely the result of the combined action of tectonic and magmatic processes acting since Proterozoic times. While the crustal structure in Ireland is reasonably well known, particularly over the Irish segment of Iapetus Suture Zone, the uppermost mantle structure requires more geophysical data to contribute to the debate on hypothetical thinning of the lithosphere from south to north. In the framework of Space Weather ElectroMagnetic Database for Ireland (SWEMDI) project funded by Geological Survey Ireland, long-period magnetotelluric data at over twenty stations are currently being acquired to resolve the electrical conductivity distribution of the lower crust and the uppermost mantle beneath the whole island. This new dataset together with the existing MT dataset at over thirty stations (ISLEMT - Irish Magnetotelluric Lithosphere Experiment) across Iapetus Suture Zone will be modelled in 3-D. The resulting electrical resistivity model will be combined with seismic, gravity, elevation and surface heat flow datasets to study thermal and compositional structure of present day Ireland's lithosphere. To that aim, an integrated geophysical-petrological approach (LitMod) will be used, where electrical conductivity, density and seismic velocities are dependent on modal mineralogy, temperature, composition, water content, and presence of melt.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMGP31D0739K
- Keywords:
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- 0699 General or miscellaneous;
- ELECTROMAGNETICSDE: 1219 Gravity anomalies and Earth structure;
- GEODESY AND GRAVITYDE: 1515 Geomagnetic induction;
- GEOMAGNETISM AND PALEOMAGNETISMDE: 7270 Tomography;
- SEISMOLOGY