image of diamond

Drilling

"The Rotary Lie Detector". This is the ultimate test of exploration – all of the desktop, sampling and geophysical work leads to drilling targets.  Kimberlite targets, in many cases, can only be properly tested by drilling because a few metres of overburden precludes pitting, clay horizons prevent auger samples being collected from bedrock and for many other valid reasons.

When drilling kimberlites, it is sufficient in the first instance to simply collect rock chips to identify kimberlite from which indicator minerals may be recovered.   If the rock encountered is not kimberlite, geophysical measurements are made to be certain that it is the source of the magnetic anomaly but if not, a second hole may be drilled, on geophysical evidence, some metres from the first.

The choice of method is therefore easy to make – Rotary Air Blast drilling – or, if uncontaminated samples are required, Reverse Circulation Percussion drilling.  Drilling on gold or other mineralised targets may, however, require core to be recovered so that assays can be carried out on split core samples.

contractors-drilling

Leland currently employs tow drill rigs.  The first targets were drilled to the east of the watershed, near Tabora (picture above).  Initial results confirm an excellent “hit rate” converting geophysical anomalies to kimberlites.  Drilling also continues to the west of the watershed, wouth of Tabora, although no kimberlites have yet been intersected from Clarity Mineral Services.