Gravity Surveys

Knowledge in the Field

Gravity surveys are used to map rocks of different densities. Large-scale regional surveys are used to map intrusions potentially hosting low-grade gold mineralization, mapping basement structures or locating blind ultramafic intrusions.  Detail surveys are effective in massive sulphide and kimberlite exploration.

AGL Delivers

AGL provides gravity surveys with Scintrex CG-3 and CG-SAutograv precision gravimeters and uses spirit leveling, differential GPS and carrier phase GPS survey techniques for elevation control, depending upon the accuracy required.   Terrain corrections are performed with reflectorless laser rangefinders in the region near the gravity station and with digital terrain models of varying detail from 200 m to 160 km from the station. Terrain corrections need to be extended to great distances in rugged terrain where distant topography affects the vertical gradient in the Bouguer anomaly.

Data processing normally includes frequency domain filtering or upward continuation to estimate and remove the regional Bouguer anomaly. As with magnetics, AGL offers forward and inverse modeling to derive knowledge of the source body geometry.