Preview - Volume 2022, Issue 219, 2022

The high-grade Au-Cu Havieron deposit exhibits near coincident ovoid magnetic and gravity anomalies and was discovered in 2018, under 420 m of post-mineralisation cover, through geophysical modelling and drilling.

At Havieron, the aeromagnetic image defines a 100 nT near-circular magnetic anomaly having a half-width of 800 m within generally bland magnetic terrain. Gravity data define an irregular gradient with values decreasing to the north east. Three large WNW trending sand dunes disrupt the Bouguer gravity image due to over-correction using the standard density of 2.67 gm/cc, but the disruption is reduced using a density of 1.50 gm/cc consistent with the notion that the dunes consist of loose dry sand. The revised gravity image shows an obvious bulge in the contours of the gravity gradient which appears as a weak (0.5 mGal) irregular gravity ovoid in a residual gravity image. The peak of this ovoid is at least 200 m to the south of the magnetic peak. Including a remanent magnetic vector in the magnetic model simplified the model body and shifted it southward to a position coincident with the residual gravity anomaly. The discovery hole was designed to intersect this coincident source of the magnetic and gravity anomalies.