Salt Interpretation with Special Focus on Magnetic Data, Nordkapp Basin, Barents Sea

A salt diapir in the Nordkapp Basin, Barents Sea, is interpreted from seismic, gravity gradiometry and high resolution magnetic data. Special emphasis is given to the magnetic data, which are shown to overcome some of the problems of gravity data, which includes non-contrast density zones, density variation of evaporate rocks and ambiguity with respect to mother salt. The magnetic attributes of the sedimentary environment are derived from onshore analogs and well data of the same geological strata. The interpretation method combines 3D modeling and inversion. Starting on a regional scale, the crustal structure is resolved using a model defined by regular grid layers. The residual anomalies on a ‘seismic’ scale require more complexity and are interpreted by modifying triangulated layers on vertical sections as well as by inversion of a 3D grid model of the innermost area enclosing the salt diapir.