Hydrocarbon & Mining Geophysical Exploration Services

• Gravity data acquisition, processing, and interpretation.  Westshore Consulting is a recognized expert in collecting, processing, and interpreting densely sampled precise gravity data. Densely sampled precise gravity data has several exploration applications, including:

• Defining subsurface structures and stratigraphic features where the density contrast, along with the size of the features, are large enough.  Simple computer models can be utilized to determine the applicability.

• Defining seismic static correction "problem areas" before, or years after, seismic acquisition. The near-surface velocity variations that cause most static correction problems are also generally shallow-density variations, which can reliably be identified as high-frequency (because of their shallow depth) gravity anomalies.

• Improving the accuracy and usefulness of gravity interpretations by increasing the frequency content of the survey. More broadly sampled gravity surveys mistake high-frequency noise for signal and miss the higher frequency characteristics of anomalies.

• Delineating glacial bedrock scours. Glacial bedrock scours, or channels, buried by glacial drift cause unique, high-frequency gravity anomalies which can be delineated with densely sampled gravity data. The locations of these features are important for a number of reasons in glaciated terrain.

• Providing information important to the mining industry, including the location of buried channels and the boundary of ore bodies which often have anomalous densities.

• Ground magnetic data acquisition, ground magnetic and aeromagnetic data processing, and magnetic survey interpretation.  Magnetic data is useful in both hydrocarbon exploration and mining exploration.  In hydrocarbon exploration aeromagnetic data is an effective method for locating strike-slip faulting in magnetic (or crystalline) basement.  This is because when magnetic basement is formed it is made up of accreted or intruded bodies which in general, each contain unique amounts of magnetic minerals.  The new magnetic basement is brittle, so when regional horizontal stress is applied, the basement breaks along strike-slip faults.  After strike-slip faulting has broken up magnetic basement, the magnetic anomalies associated with the accreted or intruded bodies are abruptly terminated by the strike-slip fault.  When a large magnetic data set is reviewed using appropriate techniques, these abrupt terminations “line up” allowing definition of a “magnetic lineament.”  Locating magnetic lineaments (or strike-slip faults in magnetic basement) is important because as tectonic stress is applied to a region these deep-seated strike-slip faults are reactivated and cause displacement in overlying younger strata.  In Michigan and other areas strike-slip motion in Ordovician strata are believed to have caused fracturing, allowing hydrothermal dolomite formation associated with reservoir development.  By identifying the position of strike-slip faults in magnetic basement the general position of the overlying Ordovician strike-slip faults can be located.  This information can then be used to more effectively locate costly 3-D seismic surveys.  In mining exploration, ground magnetic or aeromagnetic data is used to locate ore bodies whose magnetic mineral content (and therefore its magnetic susceptibility) is different from the surrounding country rock, causing a magnetic anomaly.