Irish exploration and project development company Botswana Diamonds has identified kimberlite pipes at its Thorny River project in South Africa, following geophysical work.

Many of the targets identified are similar to the pipe that constituted the De Beers Marsfontein mine. The company said that the pipe had very low surface indication due to the presence of dolerite rock cover.

Much of the Thorny River area geology comprised a dolerite dyke swarm. Conventional geophysical techniques have been unable to detect kimberlites under the dolerite rock cover, which are deep-seated.

Subterrane, the company’s partner, will enable it to explore geophysical anomalies beneath the dolerite cover and those that are already buried, leading to the discovery of kimberlites similar to Marsfontein.

Until now, Subterrane has identified five such target areas within the Thorny River project.

Botswana Diamonds chairman John Teeling said: “It has long been held that there should be high grade kimberlite pipes other than the Marsfontein mine in the Thorny River area.

“The geology made discovery difficult. New geophysical technology tries to see through the dense dolerite cover. The company pioneering the work, Subterrane, believe they have identified five targets likely to be kimberlites.”

In April, the company completed drilling programmes at its Frischgewaagt and Hartbeesfontein farms.

Last October, it completed an agreement with Vast Resources to develop concessions in the Marange Diamond Fields (MDF) of eastern Zimbabwe.

In June the same year, Botswana Diamonds secured a 2.5ha Mooikloof kimberlite pipe concession in South Africa.