Aviat Conceptual Study Outlines 24.1- 40.3 Million Carats Of Diamonds


Stornoway Diamond Corporation (TSX-SWY) and Hunter Exploration Group (Hunter) are pleased to report the results of a conceptual study completed by SRK Consulting ("SRK") for the Eastern Sheet Complex ("ESC") of the Aviat Project. 

Highlights of the conceptual study are as follows:

  • 12.4 to 16.0 million tonnes total content of kimberlite material from a conceptual model of four kimberlite dykes of the ESC; one interpreted dyke, ES 1 (previously known as A267), spans an area of some 260 hectares and represents about 78% of the total kimberlite volume
  • 235 carats per hundred tonnes (cpht) +/- 30 cpht conceptual estimate of total diamond content, assuming 100% recovery of stones in all size fractions down to a +1.00 mm bottom cut-off and based on limited micro and macro diamond data collected during the 2003 to 2007 field campaigns
  • 24.1 to 40.3 million carats in the ground, using the conceptual range of total content of kimberlite material, conceptual estimate of total diamond content and an allowance for approximately 5% internal dilution within the conceptual model (see below for more details)

The potential quantity of diamonds that can be inferred from the above estimates is conceptual in nature and does not constitute a mineral resource. The reader is cautioned that to date there has been insufficient exploration to define a mineral resource according to CIM Definition Standards for Mineral Resources and Mineral Reserves for the ESC, and it is at this stage uncertain if further exploration will be able to delineate a mineral resource for the ESC. 

The 486,000 acre Aviat Project is located on the Melville Peninsula in eastern Nunavut, Canada, and is a joint venture between Stornoway (90%) and Hunter (10%), with Stornoway holding 100% of the diamond marketing rights. In order to simplify the historical naming convention of the outcropping sheet-like kimberlites at Aviat (AV267, AV38, etc.), the bodies in this conceptual geological model have been re-classified into four main sheets referred to as ES 1, ES 2, ES 3 and ES 4. A map outlining the series of significantly diamondiferous kimberlite pipes and sheets on the Aviat Project is available here. A 200t sample of the ES 1 kimberlite was collected during the 2008 summer season and is pending Dense Media Separation (DMS) processing. 

Stornoway's CEO Eira Thomas commented: "The new Aviat conceptual study, taken together with the upcoming NI 43-101 resource study at Renard, expected shortly, promises to give Stornoway one of the leading inventories of undeveloped diamond resources in the world." Eira Thomas further stated: "The kimberlites that comprise the Eastern Sheet Complex are high grade, laterally contiguous, shallowly dipping and not overlain by any major water bodies. ES 1 and 2 have surface outcrop exposures, and approximately 80% of the current potential mineral deposit is situated within 100m of surface. Most of our drilling has focused on near surface portions of ES 1, but we see significant expansion potential down-dip, elsewhere within the ESC, and in the pipe-like bodies that were not incorporated into this analysis. We are anticipating initial processing results from a 200 tonne sample of the ES 1 kimberlite towards year-end which will provide additional insight into the grade, diamond value and overall economic potential of this large scale, and growing, diamond camp." 

SRK Consulting (Canada) Inc. ("SRK") an independent, international consulting practice, was engaged to (i) develop a conceptual geological model for kimberlite dykes of the ESC, (ii) provide a range of potential kimberlite volume and tonnage, and (iii) estimate conceptual total diamond content within the extent of the bodies as known from current drilling (see Press Release of September 08, 2008). This conceptual study does not include Aviat's pipe-like kimberlite bodies (AV1, AV4 and AV9), kimberlite sheets outside of the ESC (such as AV1W and AV5) or drill intersections of as yet un-named kimberlite sheets that have not yet been integrated into the overall geologic model. 

Kimberlite dykes of the ESC comprise a series of stacked, subparallel, shallowly dipping (8-20 degrees) sheets that cover an area of approximately 260 hectares and are composed of macrocrystic, hypabyssal kimberlite and kimberlite breccia assumed to represent a single phase of kimberlite magma. The conceptual geological model developed by SRK consists of four distinct dyke horizons, the largest of which, ES 1,is interpreted to extend continuously from the original AV6 surface discovery southeast to the original AV8 discovery, average 1.7m true thickness and underlie the entire 260 hectare area. One of the three other distinct dykes modelled by this study, ES 2 (1.3m average thickness), is a hanging wall dyke situated 10-20m above the northwest part of ES 1, and the two other bodies, ES 3 (1.3m thick) and ES 4 (0.9m thick), are stacked footwall dykes situated 10-20m, respectively, below the southeastern extent of ES 1.

A total of 96 vertical and inclined drill holes spaced at roughly 150 to 300m intervals, of which 81 encountered kimberlite intersections from a few centimetres to 16.0m in thickness, have been incorporated into the conceptual geological model by SRK. Kimberlite intersections were classified into one of the four main ES dykes based on elevation. For horizons with multiple, close spaced kimberlite intersections separated by non-kimberlitic country rock, the kimberlite units were grouped into a single envelope so long as kimberlite units were greater than or equal to 0.25m in thickness and separated by less than 1.5m of country rock. This inclusion of internal waste provides approximately 5% internal dilution, therefore the overall proportion of kimberlite within the current geological interpretation is approximately 95%. At this stage it is impossible to estimate potential mining dilution. The volume of kimberlite dyke generated by the current conceptual model is estimated to be in the range of 4.7 to 6.1 million cubic meters, with the higher volume estimate including a down dip extension to the regional scale northwest-southeast trending Centennial fault zone (used as the southwestern limit for the purposes of this conceptual geological model). Some 72 to 78% of the total kimberlite volume is attributed to ES 1. The average specific gravity determined from 18 samples collected to date is 2.63 g/cc, providing the tonnage ranges of 12.4 to 16.0 million tonnes reported above.

Total diamond content estimation of the ES dykes (235 +/- 30 cpht undiluted) was determined by SRK using both micro and macro diamond data provided by Stornoway. A total of 529 microdiamonds from 409 kg of drill core, and 33.40 carats of diamonds totalling 979 macrodiamonds obtained from 20.56 tonnes of bulk sample material, were used to produce the total diamond content estimate. The estimate is considered conceptual in nature, uses a 1.0mm (+2 DTC Sieve) bottom cut-off and assumes 100% recovery of stones of all size fractions. No corrections were applied for breakage and/or loss of smaller diamonds that would typically occur during recovery of diamonds in a commercial dense media separation (DMS) plant. The increase of the estimated total diamond content from the previously reported raw bulk sample grade of 162 cpht (see Press Release of January 29, 2008) can be attributed to both this small diamond recovery factor, and also to undersampling of the larger size distribution (+11 to +23 DTC Sieve Classes) of the diamond population. The relatively small bulk samples collected to date do not appear to have representatively sampled the entire size distribution. Larger tonnage samples are required to verify the estimate of diamond content. Quantification of commercial diamond recoveries is extremely difficult at this stage of the project due to numerous factors that need to be studied in greater detail (for example: economical bottom cut-off; efficiencies of the process plant; diamond breakage and/or loss; etc.). However, SRK has stated that in a commercial DMS plant it is not unreasonable to expect a 15-20% reduction in recovered diamonds from the total diamond content estimation assuming a similar bottom cut-off of +1.00 mm.

The above estimates are conceptual in nature and do not constitute the estimation of a mineral resource. To date there has been insufficient exploration to define a mineral resource in terms of NI 43-101 for the ES dyke complex and it is uncertain at this stage if further exploration will be able to delineate a mineral resource. The conceptual geological model incorporates kimberlite dykes previously referred to AV267, AV3 Upper, and AV8 Upper (ES 1), AV2 Upper (ES 2), AV3 Lower, AV8 Middle and AV8 Lower (ES 3 and ES 4). Some significant kimberlite intersections could not be incorporated into the current model due to uncertainties in lateral continuity as a result of the relatively coarse drill pattern. ES 1 remains open down-dip to the southwest (across the Centennial Fault) as well as to the southeast along strike. Additional drilling could potentially expand the outlines of ES 1, ES 2 and ES 3, as well as allowing the correlation and delineation of unincorporated kimberlite intersections. Revisions to the model are anticipated on an ongoing basis as new information becomes available.

Next Steps
As reported previously (see Press Release of September 8, 2008) Stornoway collected a 202 tonne (wet weight) sample of the ES 1 sheet during the summer field program at Aviat which is currently being shipped south for processing to recover commercial sized diamonds. It is expected that this sample will be large enough to give a more authoritative indication of diamond content and an initial indication of diamond value within ES 1. Preliminary diamond recovery data are expected late in 2008. The results of this work, coupled with this new conceptual study, will allow an estimate of contained value with the ESC complex, and will be an important catalyst for future work that may include bulk sampling and scoping level mining studies.

Stornoway Diamond Corporation

Stornoway Diamond Corporation is one of Canada's leading diamond exploration and development companies, involved in the discovery of over 200 kimberlites in seven Canadian diamond districts. The Company benefits from a diversified diamond property portfolio, a strong financial platform and management and technical teams with experience in each segment of the diamond "pipeline" from exploration to marketing. Stornoway's diamond exploration programs are conducted under the direction of Robin Hopkins P.Geol. (NT/NU), Vice President, Exploration, a Qualified Person under NI 43-101. Mr Hopkins has read this press release and approves of its contents.

SRK Consulting

SRK Consulting provides focused advice and solutions to clients, mainly from earth and water resource industries. For mining projects, SRK offers services from exploration through feasibility, mine planning, and production to mine closure. Formed in 1974, SRK now employs more than 700 professionals internationally in 33 permanent offices on 6 continents. SRK's independence is ensured by the fact that it is strictly a consultancy organisation, holding no equity in any project. Cliff Revering, P.Eng., Senior Geological Engineer, SRK Consulting (Canada) Inc. was the Qualified Person responsible for preparation of the conceptual geological model, the range of potential kimberlite tonnage and the conceptual total diamond content estimate. Mr. Revering has read this press release and approves of its contents.

On behalf of the Board
/s/ "Eira Thomas"
Eira Thomas
Chief Executive Officer