Rock magnetic property data

Scale N/A
Coverage Various areas in the UK
Format Various tape formats and analogue records
Price £45 – £55 per tape. Subject to number of users, licence fee and data preparation fee.

The use of aeromagnetic data in recent years has taken on a new perspective in hydrocarbon exploration with the arrival of high resolution aeromagnetic surveys (HRAS), which have revealed anomalies of very low amplitude that are related to geological structures within sedimentary basins.

The interpretation of HRAS data, however, has been hampered by the paucity of magnetic property information, particularly for sedimentary rocks of Mesozoic and Tertiary ages. Although the natural remanent magnetisation (NRM) cannot be neglected, the magnetic susceptibility of a rock provides a basis for undestanding the magnitude of the total magnetisation.

Susceptibility data have been collected by BGS over many years, particularly for igneous and metamorphic rocks, using laboratory and field instruments and a downhole sonde. A project concerned with the acquisition of data for sedimentary rocks relevant to hydrocarbon exploration has recently been completed and the report and accompanying digital database are now available.

The results presented include:

  • systematic magnetic susceptibility data based on more that 10 000 measurements on more than 11km of core from 70 offshore and onshore boreholes in the BGS and DTI collections
  • measurements on sedimentary rocks from sequences of Carboniferous to Quaternary age, igneous rocks of Permo-Carboniferous and younger ages and volcanogenic sediments associated with Palaeogene igneous activity
  • a comprehensive digital database based on the foundation provided by these new data, complemented by published material on induced and remanent magnetisations
  • an assessment of the value of the data to the interpretation of HRAS results, including some modelling studies
  • guidelines for assessing potential sources of anomalies in sedimentary basin environments
  • a summary of results from published HRAS case histories
Hutton field: well correlation diagram.