DIAMOND PAGE — Ashton unimpressed with Buffalo Hills sample

Disappointed by results from a mini-bulk sample, Ashton Mining of Canada (ACA-T) has suspended sampling work at kimberlite K-91 on the Buffalo Hills project in north-central Alberta.

A 35.87-tonne sample of K-91, collected by a combination of core and rotary drilling from four large-diameter holes, yielded an aggregate 4.561 carats of diamonds exceeding 0.8 mm in size. The preliminary grade of the sample was 12.7 carats per 100 tonnes (or 0.127 carat per tonne), and the two largest stones recovered weighed 0.45 and 0.41 carat.

The K-91 kimberlite lies 2.3 km northwest of the K-14 complex and sits beneath just 14 metres of overburden. The magnetic signature measures 400 by 100 metres. Two of the four large-diameter holes were drilled vertically in the northern portion of the magnetic anomaly, whereas the other two were drilled some 200-250 metres south. One of the holes in the southern portion returned 2.372 carats from a 14.84-tonne sample, resulting in an indicated grade of 16 carats per 100 tonnes.

In Canaccord Capital’s Daily Letter, mining analyst David James described the low-grade results as “disappointing and not good news for the Ashton/Pure Gold/AEC venture, nor the Alberta diamond play generally.”

Initial microdiamond testing in late 1997 showed the K-91 body to have one of the highest counts among the Buffalo Hills kimberlites, returning 12 macrodiamonds and 180 micros from a 117-kg sample. (A macro is defined as exceeding 0.5 mm in at least one direction.) The remaining samples from the initial drilling were processed by dense media separation. A 0.301-carat parcel, exceeding 0.8 mm in size, was recovered from a 0.85-tonne sample, giving an indicated grade of 35.4 carats per 100 tonnes. The largest stones recovered weighed 0.14 and 0.13 carat.

Ashton states that “overall, the results are an encouraging indication that diamonds are widely distributed through the kimberlite.”

Ashton is operator of the Buffalo Hills joint venture and holds a 42.5% interest in the central 1.4-million-acre claim package, where 23 kimberlite bodies have been uncovered. Alberta Energy (AEC-T) also holds a 42.5% interest, with the balance held by Pure Gold Minerals (PUG-T). The joint-venture partnership also covers 4.1 million acres of surrounding ground.

A broader, 22.7-million-acre package is 49%-owned by Pure Gold, with the balance divided equally between Ashton and Alberta Energy.