xela1 a few meters is correctI did some more checking on the aeromagnetic survey. Flight lines were 200m apart. Over 99% of the repeat readings on the GPS base station were within 5 meters. It looks like your original statement that the magnetic anomaly could be misplaced by 'a few meters' is correct (up to 5 meters) but certainly NOT by 1,500 meters.
So, if we accept that the gravity anomaly and the magnetic anomaly are not at the same place and are in fact 1500 meters apart, where does that lead us?
Owl