New discovery at Amaruk proves diamond-bearing

While microdiamond results are positive for the first of four new kimberlites discovered last year by Diamonds North Resources (DDN-V, DDNFF-O) on the Amaruk property in the Pelly Bay area of Nunavut, there is a noticeable lack of larger-sized stones.

A 60.28-kg sample of rock chips collected from the discovery hole on the Qavvik kimberlite returned 55 rough diamonds based on a cutoff of 0.106 mm, or 91 microdiamonds in total using a lower cutoff of 0.075 mm. There were no diamonds recovered in upper size sieve fractions of 0.425 mm or better. The three largest microdiamonds were caught on the 0.3-mm sieve and measure 0.51 by 0.46 by 0.42 mm, 0.51 by 0.43 by 0.36 mm and 0.51 by 0.43 by 0.32 mm.

Microdiamond results are pending for an additional 400 kg of sample collected from a second drill hole into Qavvik.

Diamonds North blames the absence of larger diamonds on the relatively small sample size and the pulverization of the sample material by the reverse-circulation (RC) drill. The company used a lightweight, portable RC rig last year to test 26 targets, which were scattered over a 75-km-wide area in the south-central part of the property. While Diamonds North considers the reconnaissance RC drilling to be a cost-effective exploration tool, it does acknowledge that a certain amount of diamond loss is expected.

The drilling resulted in the discovery of four new kimberlites — Qavvik, Char, Walrus and Beluga, and confirmed the existence of Umingmak, an outcropping fifth body that was found during the 2005 field season. All the targets were vertically drilled to a maximum depth of 65 metres, with the exception of Char and Umingmak, which were drilled at a minus 60 angle. The targets covered a wide range of magnetic signatures. Some of the holes did not reach bedrock due to the limitations of the small drill rig. The magnetic signatures of the five kimberlites vary in size, ranging from 145 by 80 metres for Walrus to 290 by 120 metres at Umingmak. Qavvik is represented by a magnetic anomaly measuring 4 hectares in size.

Umingmak is exposed in three outcrop showings in a topographically low, overburden-covered area. The discovery was described as an olivine-rich macrocrystic kimberlite, with lots of visible chrome diopsides and purple-coloured garnet, plus ilmenite.

Diamonds North pulled 602 kg of sample from two surface showings 50 metres apart on Umingmak and recovered a previously reported 166 microdiamonds exceeding 0.106 mm in size. The biggest stone, measuring 1 by 0.78 by 0.38 mm, was the only diamond caught on the 0.6-mm sieve.

In newly released numbers, only 27 microdiamonds exceeding 0.106 mm were recovered from 246.8 kg of drill cuttings — disappointing numbers as the two biggest stones were caught on the lower-size 0.212-mm sieve.

Microdiamond results are pending for the Char, Walrus and Beluga discoveries.