Ashton discovers kimberlite in Mauritania

Australia’s Ashton Mining has discovered what it believes is the first fully-documented diamond-bearing kimberlite pipe in Mauritania, northern Africa.

Selected reverse-circulation drill samples totalling 369.2 kg from the discovery hole of a new kimberlite pipe at the Maqteir license in the northern part of the country have yielded 47 microdiamonds and 31 fragments of larger stones weighing a total of 2.86 carats.

The diamond fragments are interpreted to be derived from at least seven stones measuring greater than 0.8 mm. The largest stone is believed to have consisted of 3 fragments weighing more than 1.7 carats.

The discovery hole hit kimberlite at 50 metres of depth after passing through poorly consolidated sandy overburden, and continued in kimberlite until drilling was suspended at 150 metres depth. The pipe is estimated from magnetic data to be about 8 ha in surface area.

A second series of samples — taken from the same hole as a check — returned only 5 micros from 244.6 kg. Ashton believes the variability reflects the complex geology of the kimberlite pipes. Even so, the company considers the results to be very encouraging.

Ashton’s joint venture partner, Dia Met Minerals (DMM-T), is currently assessing Ashton’s microdiamond and mineral chemistry results, including examination of the recovered stones. A drill rig is being mobilized to the site so that an adjacent hole can be drilled to further substantiate the results from the first hole. Additional stepout holes will be drilled to obtain more information about the distribution of diamonds in the body and its size potential.

Dia Met can earn up to 49% interest in the more than 180,000 sq. km of licenses held by Ashton in Mauritania by spending a total of US$10 million on exploration. The Mauritanian government holds a 10% interest in some of the licences included in the joint venture. Dia Met has spent some US$3.7 million to date. Ashton is the operator of the project.