Coronation pipes return strong counts

A new kimberlite camp is emerging some 50-120 km south of Coronation Bay in the northern Slave Craton region of Nunavut. Discoveries by Ashton Mining of Canada (ACA-T) and Kennecott Canada Exploration are yielding strong early-stage microdiamond counts comparable to some of the early counts from the Lac de Gras area, a few hundred kilometres to the southeast.

The Artemisia kimberlite, discovered this fall by Ashton on the Kim property, 50 km south of Coronation Bay, has returned 342 microdiamonds and 38 macros from a 103.2-kg of sampled drill core. (A macro is here defined as exceeding 0.5 mm in at least one dimension.) Thirteen of the macros are greater than 0.5 mm in two dimensions, and the three largest stones measure 1.23 by 1.15 by 1.1 mm, 1.13 by 0.8 by 0.68 mm, and 0.94 by 0.92 by 0.8 mm. More material from the discovery hole will be analyzed for microdiamonds.

Ashton returned to the Kim property this past summer to investigate indicator mineral dispersion trains identified in previous years. One of the follow-up till samples taken this year returned more than 300 indicator grains, as well as a diamond measuring 0.7 by 0.56 by 0.45 mm. Further work revealed kimberlite outcrop and float in an area of 150 by 140 metres.

A vertical hole was collared in the centre of this area, resulting in the discovery of the Artemisia kimberlite. The hole cut kimberlite breccia diatreme close to surface and shut down in kimberlite at a depth of 169 metres.

During the fall drilling, Ashton collected a 1-tonne test sample of outcropping kimberlite from Artemisia, which will be processed for macrodiamonds. Results will not be available for the next 2-3 months.

The Kim property is part of the Slave regional joint venture, consisting of Ashton and Pure Gold Minerals (PUG-T). On completion of the 2001 exploration program, Ashton will hold about a 90% interest in the joint venture, with Pure Gold holding the remainder. The partners recently staked a further 200 sq. km of mineral claims, boosting their land holdings in the region to 1,750 sq. km.

The Kim property adjoins the western property boundary of the Kikerk Lake property, which hosts the diamondiferous Potentilla kimberlite, 10 km east of Artemisia. Ashton can earn up to a 59.5% interest in Kikerk Lake from Caledonia Mining (CAL-T). The Northair Group’s Northern Empire Minerals (NEM-V) retains a 30% working interest.

Potentilla has yielded 230 micros and 22 macros from a 207.8-kg aggregate drill sample of two distinct facies. Samples of the diatreme phase weighing 129.1 kg returned 160 micros and 15 macros. Seven of the macros measured more than 0.5 mm in two dimensions, with the three largest stones measuring 2.13 by 1.94 by 0.87 mm, 1.37 by 0.99 by 0.87 mm, and 1.12 by 0.9 by 0.4 mm.

The deeper hypabyssal phase returned 70 micros and seven macros from 78.7 kg of drill core. Three of the macros were greater than 0.5 mm in two dimensions, with the biggest stone measuring 0.8 by 0.52 by 0.39 mm.

Ashton discovered Potentilla while drill-testing targets associated with two distinct indicator mineral trains. One diamond, measuring 1.4 by 0.68 by 0.6 mm, was recovered, along with more than 1,900 indicator mineral grains from a single till sample taken near the head of the dispersion train associated with the Potentilla discovery.

The Kim and Kikerk Lake properties lie 500 km north of Yellowknife and 100 km southeast of Kugluktuk (formerly known as Coppermine).

Rhonda‘s (RDM-V) Knife pipe sits 15 km southwest of Kikerk Lake. The Canadian exploration division of De Beers Consolidated Mines discovered the multi-phase pipe last year. Twenty samples representing an aggregate of 397 kg yielded 208 micros and nine macros weighing a total of 0.1275 carat. Delineation drilling has confirmed the pipe’s dimensions of 390 by 230 metres, equivalent to a surface area of about 6 ha.

70% interest

De Beers collected nine tonnes of kimberlite from six holes drilled into the Knife pipe this spring for macrodiamond analysis at its South African lab. Diamond counts are pending. The South African major can earn a 70% interest in the 10-sq.-km Knife property by spending $10 million on exploration over six years. Rhonda will retain a 30% interest carried to production.

Rhonda also holds a 100% interest in the 490-sq.-km Inulik property, which is contiguous with the Knife property. The junior conducted a summer sampling program across the property, collecting 570 glacial till samples.

To the south, Kennecott has made three kimberlite discoveries since beginning an exploration campaign this summer on the Rockinghorse property. Rio Tinto‘s (RTP-N) Canadian diamond exploration arm can earn up to a 62.5% interest in the large block of claims from Tahera (TAH-T) by funding all costs through to completion of a bankable feasibility study.

The Anuri kimberlite was discovered in July at the head of a prominent indicator mineral train and is significantly diamondiferous. In total, 600 micros and 337 macros were recovered from 656 kg of kimberlite core. Sixty-one of the macros were larger than a 0.5-mm square mesh screen size, and nine of the macros exceeded a 1-mm square mesh size. The largest stone recovered weighed three-quarters of a carat.

The discovery prompted Kennecott to stake more ground in the area carry out geophysical surveys and infill till sampling within a 20-sq.-km radius around Anuri. The company followed up with the discovery of a second kimberlite body, immediately east of Anuri in a small bay of Tak Lake. A 78-kg sample taken from a 36-metre kimberlite intercept of Anuri East has yielded 50 micros and 18 macros. Two of the macros exceed a 0.5-mm square mesh size, including a single stone recovered from a 1-mm square mesh screen.

Results from Qamutiik are pending. A land-based kimberlite body, it was discovered 9 km northwest of Anuri and its companion. Exploration drilling at Rockinghorse will resume in February. The Anuri kimberlites will be further evaluated, along with some 25 other targets.

In related news, Kennecott carried out reconnaissance work this fall on Tahera’s Jericho project, 120 km southeast of Rockinghorse. The field program was designed to generate drill targets within a 10-km radius of the Jericho kimberlite pipe. Kennecott’s work identified four distinct occurrences of kimberlite float in association with previously defined indicator mineral trains.

Kennecott has taken an option on the Jericho project and will have a year in which it can elect to incorporate the project into the existing joint venture with Tahera. Kennecott is required to spend at least $1 million drilling a minimum of 20 targets.