Benjumea B.,Icgc Institute Cartografic I Geologic Of Catalonia |
Macau A.,Icgc Institute Cartografic I Geologic Of Catalonia |
Gabas A.,Icgc Institute Cartografic I Geologic Of Catalonia |
Esquerda M.,Icgc Institute Cartografic I Geologic Of Catalonia |
Figueras S.,Icgc Institute Cartografic I Geologic Of Catalonia
Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics | Year: 2014
This study reveals the importance of reprocessing vintage seismic data, originally focused on deep targets, in order to retrieve near-surface velocity model and structure. This information can be verified and complemented using cost-effective geophysical methods (passive seismic and audio-magnetotelluric - AMT data technique). This methodology has been applied to the Empordà Neogene basin (NE of Spain) where oil reflection datasets are available. 41 H/V stations were deployed along one seismic reflection profile to detect seismic impedance contrast between Quaternary/Neogene sediments and basement (Palaeozoic and Mesozoic). In order to calculate this contrast depth, shear-wave velocity profile has been obtained using seismic noise array technique. The final model obtained from the different seismic datasets show a basin shape with a gentle dip at the SW end of profile and an abrupt dip at the NE side interpreted as the Roses Fault. Bedrock depth reaches 660 m at the center of the profile according to H/V results. Finally, an AMT survey was undertaken at 10 sites to report a detailed 2D geoelectrical image across the Roses fault. The electrical resistivity model allows to characterize both structure and fluid properties associated with fractures network within the fault.