DIAMOND PAGE — New AK kimberlites yield diamonds

Three kimberlite discoveries on the AK property in the Northwest Territories have proved to be diamondiferous.

The AK and CJ properties are a joint venture among Monopros, Mountain Province Mining (MPV-T) and Camphor Ventures (CFV-V). Monopros, the Canadian exploration division of De Beers Consolidated Mines (DBRS-Q), can earn a 60% interest in the properties by advancing them to production. Mountain Province is carried to a 36% interest, while Camphor is carried to 4%.

The AK property is 320 km northeast of Yellowknife and 115 km southeast of Lac de Gras.

The discovery hole of the Wallace kimberlite body yielded nine macrodiamonds and 72 microdiamonds from 40 kg of kimberlite (De Beers classifies a macro as exceeding a screen size of 0.5 by 0.5 mm.) Results imply a count of 2.3 macros per 10 kg. The Wallace kimberlite, 300 metres southwest of the original 5034 kimberlite, is one of five diamond-bearing bodies found in a cluster at Kennady Lake.

An 80-kg sample from the 5034 South, discovered between the Wallace and 5034 bodies, returned five macros and 284 micros, representing 0.6 macro per 10 kg. Monopros was not certain whether the kimberlite represents a new body or the continuation of the Wallace or 5034 structures.

A 40-kg sample from the Faraday kimberlite, 12 km northeast of the Kennady Lake cluster, yielded six macros and 82 micros, for a count of 1.5 macros per 10 kg. The Faraday discovery yielded the first substantial intersection of diamondiferous kimberlite outside of the Kennady Lake cluster.

During a 1996 fall drilling program in the central portion of the AK property, Mountain Province intersected, at depths between 30 and 60 metres, up to seven narrow kimberlite dykes with a maximum thickness of 2.6 metres. Several microdiamonds were recovered from a small kimberlite sample.

By comparison, initial microdiamond results from other Kennady Lake pipes in 1997 included: eight macros and 101 micros from 66 kg of kimberlite from the discovery hole of the Tesla pipe, for a count of 1.2 macros per 10 kg; 33 macros and 291 micros from 132 kg from the discovery hole of the Hearne pipe, for 2.5 macros per 10 kg; 36 macros and 367 micros from 124 kg from the discovery hole of the Tuzo pipe, for 2.9 macros per 10 kg; and 88 macros and 1,565 micros from 528 kg from the 5034 pipe, for 1.6 macros per 10 kg.

Mountain Province cautions that diamonds from the three most recent discoveries were recovered from very small samples. Diamond counts can vary significantly among samples.

Monopros calculated preliminary grades and valuations for the four primary pipes based on 50-tonne, mini-bulk drill samples collected in 1998:

• the 5034 body is estimated to contain a resource of 15 million tonnes of kimberlite grading 1.6 carats per tonne at an average value of US$51 per carat, for an implied value of US$82 per tonne;
• the Hearne pipe contains 8 million tonnes grading 2.33 carats per tonne at US$44 per carat, for US$103 per tonne;
• the Tuzo pipe hosts 9 million tonnes grading 2.2 carats per tonne at US$68 per carat, for US$150 per tonne; and
• the Tesla pipe has 4 million tonnes grading 0.37 carat per tonne at US$96 per carat, for US$36 per tonne.

Last winter, Monopros collected a larger bulk sample from each of the four pipes to determine grade and value. The 5034 body yielded 980 carats of diamonds from the first 573 tonnes of a 614-tonne kimberlite bulk drill sample. The indicated grade was 1.71 carats per tonne, based on a commercial-size, 1.5-mm square screen cutoff. The three largest diamonds weighed 10, 4.9 and 4.85 carats. Results from the Hearne, Tuzo and Tesla pipes are pending.

Monopros is conducting further till sampling on the AK and CJ properties in preparation for a late-summer drilling program.