Geophysical surveys to help map buried igneous intrusions, Snowdonia, North Wales, UK

Research output: Contribution to specialist publicationArticle

Authors

  • D. P. Moseley
  • J. K. Pringle
  • R. B. Haslam
  • S. S. Egan
  • S. L. Rogers
  • R. Gertisser
  • I. G. Stimpson

Colleges, School and Institutes

External organisations

  • Hannon Westwood

Abstract

The geology of the Snowdonia National Park in North Wales comprises a mixture of Lower Palaeozoic shallow marine sediments, acidic igneous rocks and basic intrusions of the Welsh Basin that were subsequently deformed during the Caledonian Orogeny. Thin igneous intrusions are challenging to map due to variable surface exposures, their intrusive origin, structural deformation and burial by glacial sediments. This study used a combination of traditional geological techniques, near-surface geophysical surveys and remote sensing to detect and map a buried dolerite sheet intrusion. Both simple and mathematical analysis of magnetic anomalies and numerical modelling allowed the dolerite position, depths and target widths to be determined. Results showed that calibrated magnetic surveys can characterize buried igneous bodies in such mountainous environments.

Details

Original languageEnglish
Pages109-115
Number of pages7
Volume31
Issue number3
JournalGeology Today
Publication statusPublished - 12 May 2015