Multidisciplinary shallow crustal imagery at Boliden Tara Mines

 

PhD Candidate: Senad Subašić

Supervisor: Prof. Frank McDermott & Prof. Chris Bean

Funded by: Science Foundation Ireland through iCRAG

 

Abstract:

Passive geophysical methods are relatively cheap (in comparison to reflection seismic acquisition, for example) and offer the prospect of 3D imagery at a fraction of the cost of an active survey. The project aims to obtain the best possible geophysical images of the shallow crustal structure in the vicinity of the Boliden Tara Mines site, using passive methods. The multidisciplinary approach will use broadband surface-wave seismic, receiver function passive seismic, electromagnetic and gravity data sets. We will reassess existing EM and gravity data, and acquire additional measurements if there is a reasonable prospect of improving its quality. The passive seismic data will be acquired from a seismic deployment of 21 stations, lasting up to a year. The Boliden Tara Mines site has good geological constraints and other geophysical data available, and it can be used as a methodological test site for developing passive imaging methods. We want to test the performance of joint inversion of multi-disciplinary geophysical datasets, and use it to image unknown structures at increasing distances from the mine. The idea is to constrain the images over areas with good borehole and/or 2D seismic coverage, and to move away from these constrained areas in 3D using passive methods. The methodology developed at this well constrained site can be brought to other locations in Ireland and abroad.