VANCOUVER, BRITISH COLUMBIA--(Marketwired - Nov. 26, 2013) -
Highlights
- Drilling at Gecomines has outlined an Inferred Mineral Resource of 4.0 million tonnes @ 3.5%Sn for 141,200 tonnes of contained tin at a 0.25% cut-off
- The Inferred Resource was defined over 400m strike to a depth of 220m and is open at depth
- Tin mineralisation has a strong chute geometry with high grade chutes interpreted to plunge to the north
- Best intercepts were reported from the deepest holes drilled to date
- Preliminary Economic Assessment (PEA) has been suspended pending results from additional deep drilling which still needs to be conducted
- Monitoring project site security situation to resume drilling work
Alphamin Resources Corp. (TSX VENTURE:AFM) ("Alphamin" or the "Company") is pleased to announce a maiden Inferred Mineral Resource at the Gecomines target on its wholly owned Bisie Tin Prospect (Bisie Project) in east central Democratic Republic of the Congo (DRC).
The Gecomines Target Inferred Mineral Resource currently comprises 4.0 million tonnes @ 3.5%Sn for 141,200 tonnes of contained tin (at 0.25% Sn cut-off) as shown in Table 1. Drilling was focused on 400m of the Gecomines target where holes were drilled on a grid of approximately 50m x 50m down to depths of 220m below surface. The best results were reported from the four deepest holes drilled to date.
Table 1: Gecomines Mineral Resource at 0.25% Sn Cut-Off Grade, 26 November 2013
Category |
Tonnes (Million) |
Sn
% |
Sn Tonnes (Thousand) |
Cu
% |
Zn
% |
Pb
% |
Ag
g/t |
Inferred |
4.0 |
3.5 |
141.2 |
0.27 |
0.12 |
0.01 |
2.2 |
Total |
4.0 |
3.5 |
141.2 |
0.27 |
0.12 |
0.01 |
2.2 |
Notes:
- All tabulated data has been rounded and as a result minor computational errors may occur
- Mineral Resources which are not Mineral Reserves have no demonstrated economic viability.
- Alphamin has a 100 percent interest in the Bisie Project. Accordingly, the Gross and Net Attributable Inferred Mineral Resources are the same.
The Mineral Resource was prepared by an independent consulting company, The MSA Group (MSA), of Johannesburg, South Africa and was estimated using The Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Best Practice Guidelines (2003). The Mineral Resource is reported in accordance with the 2010 CIM Definition Standards which have been incorporated by reference into National Instrument 43-101 - Standards of Disclosure for Mineral Projects (NI 43-101). The Mineral Resource is classified into the Inferred category as shown in Table 1. A technical report prepared in compliance with NI-43-101 with respect to the initial Mineral Resource estimate will be filed on www.sedar.com.
The Mineral Resource was constrained to a maximum depth of approximately 250m below surface, the high grade mineralisation being open at depth. The top 50m has been depleted by artisanal mining activity and any mineralisation remaining in this area was not included in the Mineral Resource.
The Mineral Resource estimate was based on Sn, Cu, Pb, Zn and Ag assays and density measurements from 28 of the 37 diamond holes drilled at Gecomines. Drill holes not included in the estimate were within the top 50m depleted zone or drilled to the north and south of the main zone of mineralisation. A three dimensional grade block model was created using Ordinary Kriging. Figure 1 shows the general geometry of the mineralisation while Table 2 below details analytical and modelling methods.
To view Figure 1 please click the following link: http://media3.marketwire.com/docs/AMFig1.pdf
The Company will now continue drilling below the high grade mineralisation intersected at Gecomines to confirm grade trends at depth. The current high grade Inferred Mineral Resource was greatly influenced by the three deepest holes. Further drilling will also test the extent of mineralisation at the Golgotha target situated 750m to the south.
Preliminary Economic Assessment (PEA)
The PEA has been suspended until a revised geological model has been constructed that will include representative intersections of the mineralisation anticipated to be intersected below the current level of drilling. It is expected that these results will have a material impact on the underground mine design and optimal stoping method.
Initial work has concluded that a non-selective bulk underground mining method will be required, which can be expected to deliver mine grades substantially below those stated above.
Security
The Company has experienced delays in exploration and drilling since August 2013 when all staff were evacuated due to hostile rebel activities in the immediate surrounds. The Company field camp was raided on 9 November by a group of villagers who caused damage to company equipment and assets. The Company will assess the security situation on site and work will only resume once calm has been restored to the area and staff can return to the project site safely.
ON BEHALF OF THE BOARD OF DIRECTORS
Klaus Eckhof, Chief Executive Officer
Neither the TSX Venture Exchange nor its regulation services provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this News Release.
CAUTION REGARDING FORWARD LOOKING STATEMENTS
Information in this news release that is not a statement of historical fact constitutes forward-looking information. Such forward-looking information includes statements regarding the Company's planned exploration programs. Actual results, performance or achievements of the Company may vary from the results suggested by such forward-looking statements due to known and unknown risks, uncertainties and other factors. Such factors include, among others, that the business of exploration for tin and other precious and base minerals involves a high degree of risk and is highly speculative in nature; few properties that are explored are ultimately developed into producing mines; geological factors; the actual results of current and future exploration; changes in project parameters as plans continue to be evaluated, as well as those factors disclosed in the Company's publicly filed documents.
There can be no assurance that any mineralisation that is discovered will be proven to be economic, or that future required regulatory licensing or approvals will be obtained. However, the Company believes that the assumptions and expectations reflected in the forward-looking information are reasonable. Assumptions have been made regarding, among other things, the Company's ability to carry on its exploration activities, the sufficiency of funding, the timely receipt of required approvals, the price of tin and other precious and base metals, that the Company will not be affected by adverse political events, the ability of the Company to operate in a safe, efficient and effective manner and the ability of the Company to obtain further financing as and when required and on reasonable terms. Readers should not place undue reliance on forward-looking information.
Alphamin does not undertake to update any forward-looking information, except as required by applicable laws.
COMPETENT PERSON'S STATEMENT
The Mineral Resource estimate has been completed by Mr. J.C. Witley (BSc Hons, GDE) who is a geologist with 25 years' experience in base and precious metals exploration and mining as well as Mineral Resource evaluation and reporting. He is a Principal Resource Consultant for The MSA Group (an independent consulting company), is a member in good standing with the South African Council for Natural Scientific Professions (SACNASP) and is a Member of the Geological Society of South Africa (GSSA).Mr Witley has the appropriate relevant qualifications and experience to be considered a "Qualified Person" for the style and type of mineralisation and activity being undertaken as defined in National Instrument 43-101 Standards of Disclosure of Mineral Projects.
Table 2: Summary of resource estimate and reporting criteria
Drilling techniques |
|
All drillholes were diamond drill cored and drilled from surface (mostly NQ) at angles of between -60° and -75°.
In the Mineral Resource area, 28 of the 37 drillholes completed were used for the grade estimate, four of the holes intersected mineralisation to the north and south of the high grade zone and five of the shallow drillholes intersected artisanal workings. The data from these nine holes were not used for grade estimation. |
Logging |
|
All of the drillholes were geologically logged by qualified geologists. The logging was of an appropriate standard for grade estimation. |
Drill sample recovery |
|
Core recovery in the mineralised zones was observed to be very good and was on average 95%. Five of the shallow drillholes intersected artisanal workings and so recovery of the high grade mineralisation was poor and therefore the data from these holes were not used for grade estimation. |
Sampling methods |
|
Half core samples were collected continuously through the mineralised zones after being cut longitudinally in half using a diamond saw. Drillhole samples were taken at nominal 1 m intervals, which were adjusted to smaller intervals in order to target the vein zones. Lithological contacts were honoured during the sampling. MSA's observations indicated that the routine sampling methods were of a high standard and suitable for evaluation purposes. |
Quality of assay data and laboratory tests |
|
The assays were conducted at ALS Chemex in Johannesburg where samples were analyzed using fused disc ME-XRF05 conducted on a pressed pellet with 10% precision and an upper limit of 10 000ppm. Over limit samples were sent to Vancouver for ME-XRF10 which uses a Lithium Borate 50:50 flux with an upper detection limit of 60% and precision of 5%.
ME-ICP61, HF, HNO3, HCL04 and HCL leach with ICP-AES finish was used for 33 elements including base metals. ME-OG62 a four acid digestion was used on ore grade samples for Pb, Zn, Cu & Ag.
External quality assurance of the laboratory assays for the Alphamin samples was monitored by the insertion of:
- Blank samples collected from quartz vein on site at a rate of approximately 3% of the total sample set.
- Field duplicates consisting of quarter core on approximately 4% of the total sample set.
- Certified reference materials (CRM's): Four CRMs were used. Combined, these formed approximately 3% of the total sample set.
The QAQC measures used by Alphamin revealed the following:
- The high grade CRM (31.42% Sn) indicated that an over-assay of approximately 8% may have occurred. The lower grade CRMs (<2% Sn) indicated that the Sn and Cu assays were accurate consistently within two standard deviations of the accepted CRM value.
- The field duplicates confirmed the nuggetty nature of the tin mineralisation. The majority of the duplicate assays were within 20% of the field sample.
- Blank samples indicated that no significant contamination occurred for most of the programme. Seven blank assays returned Sn values of between 0.005% and 0.02%, which is not considered material to the project.
|
Verification of sampling and assaying |
|
MSA observed the mineralisation in the cores and compared it with the assay results. MSA found that the assays generally agreed with the observations made on the core. MSA took ten quarter core field duplicates for independent check assay, which confirmed the original sample assays within reasonable limits for this style of mineralisation. |
Location of data points |
|
All of the Bisie surface drillhole collars have been surveyed by a qualified surveyor using a differential GPS. Down-hole survey's were completed for all of the holes drilled at Gecomines. |
Tonnage factors (in situ bulk densities) |
|
Specific gravity determinations were made for the drillhole samples using the Archimedes principal of weight in air versus weight in water. Where no density data were available, a regression equation was applied. Specific gravity was interpolated into the block model using Ordinary Kriging. |
Data density and distribution |
|
Drillholes intersected the Mineral Resource at between approximately 50 m by 50 m and 100 m by 100 m spacing in the plane of mineralisation. |
Database integrity |
|
Data were stored in an Excel database. MSA completed spot checks on the database and is confident that the Alphamin database is an accurate representation of the original data collected. |
Dimensions |
|
The area defined as a Mineral Resource extends approximately 400 m along strike by 200 m on dip. The Mineral Resource is between approximately 10 m and 20 m thick, although narrower zones occur to the north. |
Geological interpretation |
|
The mineralised intersections in drill core are clearly discernible. The Mineral Resource is interpreted to occur as two sub-parallel locally complex vein systems of mineralisation dipping 65° to the east, in places separated by a barren zone several metres wide. The mineralised zones and intermittent waste middling are composed of chlorite schist that is the result of intense alteration that may represent a distinct stratigraphic interval. The Mineral Resource is affected by a number of faults that are sub-parallel to the mineralisation causing local displacement. The precise locations of faults have not been determined. |
Domains |
|
The mineralisation was modelled as a thick slab containing irregular vein style mineralisation. In places a waste interval was defined by Sn grades of less than 0.25%. A hard boundary was used to select data for estimation in order to honour the sharp nature of vein boundaries. |
Compositing |
|
Sample lengths were composited to 2 m. |
Statistics and variography |
|
The coefficient of variation for Sn composites is between 1.5 and 2.1, the histograms being positively skewed. Normal Scores variograms were calculated in the plane of the mineralisation layering, down-hole and across strike. Variogram ranges were 120 m in the in-plane direction and 10 m across strike. |
Top or bottom cuts for grades |
|
Top cuts were applied to outlier values that were above breaks in the cumulative probability plot. |
Data clustering |
|
Drillhole intersections were not clustered, the grid being approximately regular. |
Block size |
|
4 mN by 40 mE by 40mRL three dimensional block models as optimised using a Kriging Neighbourhood Analysis. The blocks were rotated into the plane of mineralisation prior to estimation. |
Grade estimation |
|
The accumulation of grade and density were estimated using Ordinary Kriging. Estimation parameters were optimised using a Kriging Neighbourhood Analysis.
A minimum number of 8 and a maximum of 16 two metre composites were required to be selected within 120 m of a block in order to achieve an estimate. Grades were extrapolated in the plane of the mineralisation for a maximum distance of 40 m from the nearest drillhole intersection, this being considered by MSA to be the limit of reasonable geological interpretation for this style of mineralisation, it being possible that the mineralisation could terminate abruptly. |
Resource Classification |
|
The mineralisation was classified as Inferred Mineral Resources if block estimates were achieved with the required minimum number of samples within 40 m in the dip direction of the nearest borehole. In the strike directions half the distance between the high grade intersections and peripheral lower grade intersections was applied, this being less than 40 m. |
Mining Cuts |
|
A minimum true thickness of 2 m was applied. The considerable thickness and steep dip implies that the Mineral Resource can be extracted using established underground mining methods. |
Metallurgical factors or assumptions |
|
The tin mineralisation occurs as cassiterite, an oxide of tin (SnO2). The Cu, Zn and Pb mineralisation occurs as sulphides. Each of these minerals is amenable to standard processing techniques for each metal. |
Legal Aspects and Tenure |
|
Alphamin through its wholly owned DRC subsidiary, Mining and Processing Congo Sprl, has a "Certificat de Recherches" for PR 5266 valid to November 2014 after which it will be renewed with a 50% reduction on the licence area |
Audits and reviews |
|
The following review work was completed by MSA:
- Inspection of approximately 25% of the Alphamin cores used in the Mineral Resource estimate
- Database spot check
- Inspection of drill sites
- Independent check sampling
|