Ann: Kimberlite/Lamproite Exploration Update, page-17

Drainage depression in a rich alluvial diamond field? Trust they will look closely at the bedrock contact zone for any indications of gravels and rethink about the overall morphology of the alluvial system in case there might be a deeper paleo drainage system that could concentrate diamonds.

As stated before, the confirmed kimberlite diatremes will need large diameter drills, up to a metre wide using multi bit tables to recover enough material to process through the plant before diamonds will be seen. Last time I used one it was a S African drilling system. No doubt they are looking at those for the next phase of testing.