The geological interpretation of gravity and magnetic surveys over the exposed southern margin of the Galway Granite, Ireland
✍ Scribed by J. D. Fairhead; P. Walker
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 478 KB
- Volume
- 12
- Category
- Article
- ISSN
- 0072-1050
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✦ Synopsis
Abstract
Gravity measurements across the southern margin of the Galway granite, on the Islands of Gorumna and Lettermullen, reveal small positive Bouguer anomalies of amplitudes less than 40 g.u. associated with the denser country rock. These anomalies suggest that the ‘country rock’ is no more than a thin wedge, thickening southwards. Such a structure may form part of a large roof pendant or roof section with the true granite margin lying further south. Magnetic anomaly profiles across the granite contact reveal that the rock groups, making up the country rock, have distinct magnetic character which may provide a means of mapping their southern extent beneath Galway Bay.