Pangolin Diamonds Corp. (CVE:PAN) says it has discovered "upper terrace fluvial gravels" believed to originate from the Orapa kimberlite field, at its Malatswae south alluvial diamonds project in Botswana.
Fluvial terraces are the remnants of earlier floodplains that existed at a time when either a stream or river was flowing at a higher elevation, before its channel downcut to create a new floodplain at a lower elevation.
The company said six exploration holes were drilled to obtain a profile across an alluvial target identified from gravity surveys within the Malatswae south project area, with fluvial gravels intersected in all six holes. In all six holes, the bedrock was sandstone, it added.
Pangolin said the gravels are interpreted to represent an upper, older terrace, with the bedrock underlying the gravels intersected at "significantly shallower" levels than previous historical drilling programs.
The next phase of work for the area is a ground radar survey planned for early next year, with the results to be used to target specific sites believed to be associated with potholes and plunge pools. Plunge pools and potholes are ideally suited for the concentration of diamonds in an alluvial environment.
Pangolin said it believes that the paleo channels buried under the Kalahari Formation that it has targeted are the channels that drained the Orapa kimberlite field during the late Cretaceous period, through to approximately 2 million years ago.
The history of diamonds in Botswana dates back to the late 1950s when an exploration program by Selection Trust found the first alluvial diamonds at Foley Siding. This was followed by a campaign by De Beers, which led to the discovery of the 93 million-year old Orapa kimberlite pipe in 1967. This pipe was brought to production just four years later, generating 2 million carats per vertical metre.
The Orapa mine is capable of producing approximately 12 million carats per year.
"The shallow depth of the discovered fluvial gravels in the Malatswae South Alluvial Project area is encouraging for the recovery of mini-bulk samples in the future," said Pangolin chairman Dr. Leon Daniels, in the release.
Separately, the company also gave an update on its Malatswae North project, where it has received results for orientation drilling that has helped in narrowing the search criteria for kimberlites in the area for drilling next year. Pangolin said the area is geologically similar to the one in which Petra Diamonds discovered the KX36 kimberlite, and as such, believes that by following a similar technical route, it may be successful in finding kimberlites.
"The drilling results from the Malatswae North area are viewed as positive information that will help bring us a step closer towards the discovery of kimberlites in this complex area," said Dr. Daniels.
Last week, shares of Pangolin spiked after it said it drilled a new hole at its Magi discovery that intersected kimberlite from 35 metres depth to 94 metres. The Magi discovery earlier this year was welcomed with open arms by shareholders, who pushed up the stock some 64% in mid-October after the company announced that it modeled Magi at 270 hectares, making it one of the largest kimberlites in the world.
The company, which has four exploration properties in the world’s leading country for diamond production by value, is focused on Tsabong North, which is about 100 km north of the town of Tsabong in southwestern Botswana. The diamond explorer has found more than 50 drill-ready targets in the area, several of which have surface areas greater than 20 hectares, making it one of the largest kimberlites in the world.