Mapping depth-to-bedrock and shallow aggregate resources with airborne electromagnetics
Caven, S.; Beamish, D.; Desissa, M.; Patton, M.; Young, M.. 2010 Mapping depth-to-bedrock and shallow aggregate resources with airborne electromagnetics. [Poster] In: Mineral Deposits Studies Group 33rd Annual Winter Meeting, Glasgow, UK, 5-7 Jan 2010. Glasgow, UK, Mineral Deposits Studies Group. (Unpublished)Before downloading, please read NORA policies.
Airborne electromagnetic (EM) results have been applied to estimating depth-to-bedrock and to mapping shallow aggregate resources in selected areas of Northern Ireland. A detailed low-level airborne survey of Northern Ireland was flown in 2005-6 (the Tellus Project) in which magnetic, gamma-radiation and EM data were acquired. Data were acquired with a range of frequencies and inverted into apparent resistivity. Electrical resistivity of rocks is a function mainly of porosity, pore-water salinity, saturation and clay content. ‘Apparent’ resistivity as measured remotely is a complex function of these variables, of the geometry of the measuring system, and of local geology; the thickness and resistivity of the superficial layer are prominent factors. Depth-to-bedrock may only be determined uniquely where other parameters are consistent, where some local borehole control exists and where there is a contrast in apparent resistivity between bedrock and cover.
|Item Type:||Conference or Workshop Item (Poster)|
|Programmes:||BGS Programmes 2010 > Geological Survey of Northern Ireland|
|Additional Keywords:||Tellus, airborne geophysics, electromagnetic survey, aggregates mapping|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||09 Jun 2010 11:15|
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