North Arrow Recovers 64.25 Carats From 209.8 Tonnes at Naujaat Diamond Project, Nunavut
VANCOUVER, British Columbia, Feb. 28, 2018 (GLOBE NEWSWIRE) -- North Arrow Minerals Inc. (TSXV:NAR) is pleased to report final diamond recoveries from a 209.8 tonne mini-bulk sample collected in July 2017 from the diamondiferous Q1-4 kimberlite at the Naujaat Diamond Project, Nunavut. Highlights of this announcement include:
- A total of 1,991 diamonds greater than +1 DTC (~1 mm) weighing 64.25 carats were recovered from 209.84 dry tonnes of kimberlite for an overall sample grade of 30.6 cpht (carats per hundred tonnes).
- The three largest recovered diamonds are 5.25, 2.09 and 1.06 carats.
- Yellow diamonds, representing a range of hues and tones, represent approximately 10.7% (by stone count) of the recovered diamonds (21.2% by carat weight).
- Diamonds recovered from a subsample of the A88 phase (‘Blue’ kimberlite) include a similar proportion of yellow diamonds as seen in 2014 sampling of the A28 phase.
- The ‘Green’ kimberlite unit, also processed as a separate subsample, is interpreted as a previously unrecognized and volumetrically minor unit in the Q1-4 kimberlite and contains proportionately fewer coloured diamonds than the A88 and A28 phases.
Ken Armstrong, President and CEO of North Arrow, commented, “Diamond results from the 2017 mini-bulk sample have confirmed the presence of an important yellow diamond population in the A88 phase of the Q1-4 kimberlite. Further, the identification of the Green kimberlite as a new, previously unrecognized phase within Q1-4 underscores the under-evaluated nature of this diamond deposit. Q1-4 requires further evaluation, in particular the collection of a larger bulk sample of sufficient size to better determine the spatial and size distributions of Q1-4’s diamond population including potentially higher value coloured diamonds.”
The 2017 mini-bulk sample consisted of 209.8 dry tonnes collected from a single sample pit at the multiphase Q1-4 kimberlite, located just seven kilometres from the Company’s laydown near the Hamlet of Naujaat, Nunavut. The overall sample was divided and processed separately as three subsamples: Green Kimberlite (31 bags; subsample C1), Blue Kimberlite (A88 phase; 60 bags; sub sample C2), and Mixed Blue-Green Kimberlite (159 bags; subsample C3). A summary of the diamond recoveries from each subsample is provided in the table below along with comparable results from the 2014 bulk sample collected from the A28 phase of Q1-4 (sample A282014).
| Sample | Weight | # Diamonds | Carats | Sample Grade | Proportion Yellow Diamonds1 | |
| (Dry tonnes) | (+1 DTC) | (cpht2) | By Stones | By Carats | ||
| C1 | 27.06 | 344 | 8.46 | 31.2 | 2.6% | 3.1% |
| C2 | 51.73 | 467 | 12.99 | 25.1 | 9.9% | 9.9% |
| C3 | 131.04 | 1,180 | 42.80 | 32.6 | 11.6% | 28.2% |
| C1+C2+C33 | 209.84 | 1,991 | 64.25 | 30.6 | 10.7% | 21.2% |
| A2820144 | 1,353.3 | 11,083 | 384.28 | 28.4 | 9.0% | 21.5% |
1 includes very pale to pale to intense/dark yellow + green yellow diamonds; same colour breakdown as undertaken for sample A282014.
2 carats per hundred tonnes
3 total 2017 Pit C sample determined by arithmetic
4 As reported in North Arrow news release dated May 5, 2015.
Diamond recoveries from the overall sample include 1,991 diamonds greater than +1 DTC (~1 mm) weighing 64.25 carats from 209.84 dry tonnes of kimberlite for an overall sample grade of 30.6 cpht (carats per hundred tonnes). Recovered diamonds include 6 diamonds larger than the 3 grainer (~0.6 carat) size. The three largest diamonds, all recovered from the C3 subsample, are 5.25 carats (dark translucent, yellow to brown to white cubic aggregate), 2.09 carats (pale grey rounded aggregate with inclusions), and 1.06 carats (very pale green-yellow rounded flattish diamond with inclusions). The 2.09 carat stone retains some external kimberlite coating that would be removed with cleaning.
Yellow diamonds, representing a range of hues and tones, were compiled and documented for each of the subsamples and comprise approximately 2.6% by stone count and 3.1% by carat weight of the diamonds recovered from the C1 (Green kimberlite) subsample and 9.9%, by both stone count and carat weight, of the diamonds recovered from the C2 (A88) subsample. Yellow diamonds comprise approximately 11.6% by stone count and 28.2% by carat weight (reduced to 18.1% if the 5.25 ct diamond is removed) of the diamonds recovered from the C3 subsample, which contained a mixture of A88 and Green kimberlite.
The purpose of the 2017 sample was to acquire further information on the commercial sized (+1 mm) diamond population in the under sampled A88 phase of the kimberlite. The sampled kimberlite was easily accessed, using a small excavator, beneath approximately one metre of glacial till in a location 400m southwest of a large 1,350 tonne sample of the A28 phase collected in 2014. As reported in North Arrow news release dated September 12, 2017, the 2017 sample pit exposed a north trending internal contact between two distinct kimberlite phases. The majority of the pit area (~70%) was comprised of the volcaniclastic A88 kimberlite (field name: ‘Blue kimberlite’). The remainder of the sample pit area consisted of a dark green, coherent kimberlite unit (field name: ‘Green kimberlite’). Ongoing detailed evaluation of the Green kimberlite, including a review of drilling information, indicates this unit is a previously un-identified, volumetrically limited phase within Q1-4 that crosscuts A88 and possibly the A48b and A61 kimberlite phases of the pipe. Based on the identification of two distinct kimberlite units within the 2017 sample pit.
Mr. Armstrong continued, “As intended, this point source mini-bulk sample will help provide an indication of the diamond population and recoverable grade in a previously under sampled but accessible area of Q1-4 with the goal of providing information to help plan the collection of a larger bulk sample for the purposes of diamond valuation in support of an economic assessment of the deposit.”
The diamond results reported in this release are based on dense media separation (DMS) and caustic fusion processing and diamond extraction work completed by Microlithics Laboratories, Thunder Bay, Ontario, and I&M Morrison Geological Services Ltd, Delta, British Columbia, both independent mineral process and sorting laboratories. The sample was processed at Microlithics through a 1.5 tonne per hour DMS plant configured to recover diamonds retained on a 0.8 mm square mesh sieve. Kimberlite was fed directly into the DMS plant with plus 150 mm oversize material first crushed to 75 mm. All plus 10 mm material was subsequently reduced through staged, secondary jaw and cone crushing circuits and re-introduced into the plant. DMS concentrates were then upgraded by caustic fusion processes (single burn) and the resultant residues were shipped to I&M Morrison where they were sieved and fractions retained on a +0.85 mm Tyler (square mesh sieve) were sorted for diamonds. Some sieved fractions were further upgraded using paramagnetic separation techniques prior to diamond extraction. Quality assurance protocols, security and actual operating procedures for the processing, transport and recovery of diamonds conform to industry standard Chain of Custody provisions. 100% of inserted density tracers and natural etched diamond spikes were recovered during processing and diamond extraction. As part of North Arrow’s ongoing QA/QC programs, DMS tails, sorted caustic fusion residues, and other materials are subject to audit. Any significant changes in recovered diamond contents will be reported when available.
North Arrow’s diamond exploration programs are conducted under the direction of Kenneth Armstrong, P.Geo. (ON), President and CEO of North Arrow and a Qualified Person under NI 43-101. Mr. Armstrong has reviewed the contents of this press release.
About North Arrow Minerals
North Arrow is a Canadian based exploration company focused on the identification and evaluation of diamond exploration opportunities in Canada. North Arrow’s management, board of directors and advisors have significant successful experience in the Canadian diamond industry. In addition to evaluating the Naujaat Project, North Arrow is also preparing for exploration drilling programs this spring at the Loki and LDG Projects in the NWT and to test newly discovered diamondiferous kimberlite at the Mel Project (NU). The Company is also awaiting till sample results from its Pikoo (SK) Project and maintains a 100% interest in the Hope Bay Oro Gold Project (NU), located approximately 3 km north of TMAC Resources’ new Doris Gold Mine.
/s/ “Kenneth A. Armstrong”
Kenneth Armstrong
President and CEO
For further information, please contact:
Ken Armstrong
Tel: 604-668-8355 or 604-668-8354
Website: www.northarrowminerals.com
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for the adequacy or accuracy of this release.
This news release contains "forward-looking statements" including but not limited to statements with respect to North Arrow’s plans, the estimation of a mineral resource and the success of exploration activities. Forward-looking statements, while based on management's best estimates and assumptions, are subject to risks and uncertainties that may cause actual results to be materially different from those expressed or implied by such forward-looking statements, including but not limited to: risks related to the successful integration of acquisitions; risks related to general economic and market conditions; closing of financing; the timing and content of upcoming work programs; actual results of proposed exploration activities; possible variations in mineral resources or grade; failure of plant, equipment or processes to operate as anticipated; accidents, labour disputes, title disputes, claims and limitations on insurance coverage and other risks of the mining industry; changes in national and local government regulation of mining operations, tax rules and regulations. Although North Arrow has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking statements, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements. North Arrow undertakes no obligation or responsibility to update forward-looking statements, except as required by law.