For ground follow-up of airborne EM conductors, we use both the Geonics’ VLF EM-16 and the Intrumentation GDD Inc. Beep Mat. This method is extremely efficient where overburden is relatively shallow.
The method is simple and takes advantage of the complementary strengths of both instruments.
On the ground, the VLF is used to trace the conductor axis. In a resistive environment, the conductor can easily be traced, even if covered by several metres of overburden. Then a Beep Mat is used to cover the axis. If the conductor gets within 1.5 metres of the surface, it is picked-up by the Beep Mat. The conductor is then hand trenched, visually evaluated and sampled, if warranted. This direct evaluation allows for the accurate rating of conductive drill targets. The entire process is done quickly, without the need to cut lines.
Too often, airborne EM surveys are conducted without any ground follow-up. Drill targets are also often generated from desktops, while many anomalies could be checked on the ground both cost-effectively and accurately. Give us a call and make that airborne survey start to pay!