Richard Morgan, 1998. "Magnetic Anomalies Associated with the North and South Morecambe Fields, U. K.", Geologic Applications of Gravity and Magnetics: Case Histories, Richard I. Gibson, Patrick S. Millegan
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A close line-spaced aeromagnetic data set was acquired over the East Irish Sea in 1993 by World Geoscience Corp. Ltd. Although the area was already a known hydrocarbon province containing one of the United Kingdom's largest gas accumulations (collectively, Morecambe North and Morecambe South Fields), the aeromagnetic data reveal much about the geology of the area which previously was unrecognized.
The continuation of faults known from seismic data or from surface maps of the adjacent onshore areas is represented clearly by the magnetic data, allowing the relationships between faults of different trends to be elucidated. The geometries of major faults imaged in plan-view by their magnetic expression reveal compartmentalization by secondary cross-cutting fault suites which, although not clearly resolved by 2-D seismic data, are relevant to sediment deposition and trap formation.
An unpredicted aspect of these data is the association of weak magnetic lows with known hydrocarbon accumulations. This phenomena is expressed best over the Morecambe Fields themselves, where analysis of the shape of the anomalies in relation to the structure of the fields suggests their source to be associated directly with the structure of the closures rather than as alteration plumes above them. The cause of these anomalies is considered to be secondary mineralization, believed to relate to the complex diagenetic and multiphase charging history of these fields.
The detailed comparison of the seismically defined structure of the fields with a corresponding magnetic structure would not be possible without a close line-spaced, aeromagnetic survey configuration to define clearly the margins of these intrasedimentary-sourced, nonlinear magnetic anomalies.