Resource Statement

Griffin Mining Ld 25 November 2002 GRIFFIN MINING LIMITED 1 Berkeley Street, London, W1J 8DJ, United Kingdom Telephone: + 44 (0)20 7016 8821 Facsimile: + 44 (0)20 7016 9124 E mail: griffin@griffinmining.com 25th November 2002 NEW RESOURCE STATEMENT FOR CAIJIAYING PROJECT EXCEEDS EXPECTATIONS Griffin Mining Limited ('Griffin' or the 'Company') has today published new resource estimates for its Caijiaying zinc-gold project compiled by independent consultants Micromine Pty Ltd Consulting Division ('Micromine') in accordance with the guidelines set out in the Australian Code for Reporting of Mineral Resources and Ore Reserves (The JORC Code). A summary report written by independent geological consultants CSA Australia Pty Ltd on the new resource estimates is attached hereto. The results exceed all the expectations of the Company with 61/2 times the previously estimated contained metal now identified in the Caijiaying deposit rising from 190,000 tonnes to 1,230,000 tonnes of contained zinc metal. ZINC Ignoring the associated base and precious metals: At a 4% zinc cut-off the project now hosts an: • indicated resource of 16.9 million tonnes @ 7.84% Zinc; and • inferred resource of 6.68 million tonnes @ 8.69% Zinc; for a Total Resource of 23.6 million tonnes @ 8.08% Zinc. This compares to the previously announced total resource of 2.6 million tonnes @ 9.12% Zinc at a 4% zinc cut-off At a 7% zinc cut-off the project now hosts an: • indicated resource of 6.95 million tonnes @ 11.58% Zinc; and • inferred resource of 3.602 million tonnes @ 11.73% Zinc; for a Total Resource of 10.56 million tonnes @ 11.63% Zinc. This compares to the previously announced total resource of 1.52 million tonnes @ 12.34% zinc at a 7% zinc cut-off The new resource estimates cover only zone III at Caijiaying. The new lode orientations are consistent with mineralisation at the zone II deposit, which is situated (within Griffin's licence area) 1 kilometre to the south of the main zone III deposit. This strongly suggests that the two deposits are continuous opening up a large area for further exploration once production begins at Caijiaying. GOLD The diamond drilling programme undertaken by Griffin in the summer of 2002 encountered significant gold intercepts which taken together with earlier gold results, suggest that a distinct part of the overall deposit may have potential as a separate gold resource. In order to gain an impression of the size of this potential gold resource, Micromine compiled separate estimates for the gold resource at zone III of: 2.61 million tonnes at 6.78 g/t at a 3% gold cut off. 1.675 million tonnes at 8.63 g/t at a 4% gold cut off. 1.265 million tonnes at 9.99 g/t at a 5% gold cut off. This places over 500,000 ounces of gold at Caijiaying at a 3% gold cut off. As these estimates are based only on partial gold analyses and because the drill-hole spacing is very wide for estimating gold mineralisation, the gold resource is categorised as inferred. FUTURE Griffin is now completing a fully bankable feasibility study with a view to raising the necessary project finance and the commissioning of an underground mine at Caijiaying at the earliest opportunity. Mladen Ninkov, Chairman, commenting on the resource estimate said: 'This is one of those rare circumstances when a Chairman of a mining company doesn't need to say anything further. The new resource model, compiled by independent consultants in accordance with the guidelines set out in the JORC Code, speaks well and truly for itself. It is an amazing result and confirms the belief management has always held that Caijiaying is a world class mineral field. I am delighted for our shareholders.' The Company acknowledges the continuing outstanding contribution of CSA Australia Pty Ltd to Griffin and in relation to the Caijiaying area, and in this instance, for their outstanding efforts in identifying, analysing and completing a new geological interpretation of the mineralised structures at Caijiaying. Further information Mladen Ninkov - Chairman Telephone: +44(0)20 7016 8821 Roger Goodwin - Finance Director Telephone: +44(0)20 7016 8821 Charles Dampney - Charles Stanley Telephone: +44(0)20 7739 8200 Griffin Mining Limited's shares are quoted on the Alternative Investment Market (AIM) of the London Stock Exchange (symbol GFM). The Company's news releases are available on the Company's web site: www.griffinmining.com CSA Australia Pty Ltd Geological Consultants A.C.N 077 165 532 Level 1 47 Burswood Road Burswood Western Australia 6100 Telephone: +61 8 9355 1677 Facsimile: +61 8 9355 1977 Date; 22-Nov-02 Ref; RC.94.02 The Directors Griffin Mining Ltd 1 Berekeley Street London W1J 8DJ United Kingdom Re; The Caijiaying Project - New Resource Estimate Dear Sirs, I have pleasure in reporting the results of the new resource estimates for the Caijiaying Zone III deposit which have been prepared according to your instructions and following the receipt of the previously reported drilling results and the generation of a new geological model. Background The previous two announcements reported the results of the pre-development drilling program completed during last summer at Caijiaying and contained the following information: • The geological conclusions drawn from the drill results were that the mineralisation at Caijiaying was contained within a series of steep (75 - 80 degrees) westerly dipping, variably mineralized envelopes. It will be remembered that the orientation of these lodes was shown to be north-northeast in contrast to the east-west orientation used in previous Chinese studies. • The assay results from the drilling program confirmed the initial visual interpretations and the definition of the north-northeast, westerly dipping lodes. These data were compiled and incorporated into a new resource model by independent resource consultants Micromine Pty Ltd Consulting Division who have now released the results. The estimate has been completed by Mr Dmitry Pertel MSc, AIG, AIE and Mr Alex Belous PhD under the guidelines of the Australasian Institute of Mining and Metallurgy JORC Code, September, 1999. Mr Dean O'Keefe BSc , MAusIMM, AIE conducted an on-site due diligence check of the core library and drilling and sampling procedures. Mr Alex Belous PhD completed a due diligence assessment of the Analabs laboratory in Perth, where the drilling samples were analysed. Messrs Pertel and Belous conducted the resource computer modelling with assistance from Project Geologist Mr Warren Woodhouse BSc (Hons), MAusIMM from CSA. Procedure CSA Australia undertook the first part of the resource modelling exercise by completing a new geological interpretation of the mineralised structures. It was found that the lode geometry defined by the 2002 drilling program could be extrapolated throughout the Zone III deposit area. This allowed nearly all the previous Chinese intersections to be re-interpreted within a set of structural envelopes that parallel the steep westerly dipping lodes defined by the summer drilling program. A total of seven major sub-parallel north-northeast striking envelopes were defined with only minor disruption caused by late cross-faults and dykes. The boundaries of these envelopes were defined as the edges of variably mineralised and altered zones. In several parts, a distinct hangingwall and footwall lode was identified. However, in general, the mineralisation within the envelopes is irregular and follows discontinuities in the host rocks (as was shown by the trial mining) and is therefore more suitable for estimation by computer rather than manual techniques. The boundaries for each mineralised envelope were first interpreted in longitudinal section and then in cross section before being digitized into Micromine software. Barren cross-cutting porphyry dykes, the overlying Jurassic sequence and the transported Mongolian sand cover were also interpreted in section and digitized into Micromine in order to remove waste from the model. From the digitized mineralized envelopes a series of wireframes were constructed with the assistance of Micromine personnel. These wireframes were checked in 3D and corrected as necessary before modelling was carrying out. The entire Zone III drill-hole database was used in the modelling process. The database comprises a total of 79,472m of diamond core with 12,993 analyses for zinc and 7,586 for gold. Early Chinese samples were collected by splitting the diamond drill core and analyzing by a colorimetric method. Later drill sampling by western companies (including Griffin) consisted of cutting drill core and analyzing the core using both Australian and Chinese laboratories. Cross checking of samples was carried out using a second Australian laboratory. Micromine conducted variogram analysis within the mineralised wireframes to provide the search and grade interpolation parameters for the resource estimation. Both Ordinary Kriging and Inverse-Distance Weighting (to the squared power) methods were then used with various search parameters. The Inverse Distance Weighting method was used as a check to the preferred Ordinary Kriging Method. A sensitivity analysis with a total of seven models was run with results plotted and cross checked against the geological interpretation until a 'best fit' was obtained. The resource category was defined by the search parameters as determined from the variogram analysis, the number of samples and holes used in the calculation of a block grade. Resource Estimate Results The results of the Micromine resource estimate are presented in Table 1 at various minimum cut-off grades. The wide range of cut-off grades shown is because the first-stage mine is planned to be a relatively small-scale, high grade operation at a 7 - 8% zinc cutoff (depending on final economic factors). However, more conventional lower cut-off grades are also shown in the 4 - 6% range for comparison. These would be more likely to apply if the operation is scaled up at a later stage (depending on scale of operation and zinc price - see below). Table 1. Caijiaying Zone III Total Resource at various cut-off grades Zn Cut Off, Category Tonnes, Mt Volume, m3 Zn, % Pb, % Ag, g/t Au, g/t % 4 Indicated 16.905 5.535 7.84 0.33 31.19 0.75 Inferred 6.675 2.173 8.69 0.46 30.32 0.50 Total: 23.581 7.708 8.08 0.37 30.94 0.68 5 Indicated 12.282 3.989 9.11 0.37 35.79 0.76 Inferred 5.015 1.618 10.10 0.52 33.29 0.48 Total: 17.297 5.607 9.40 0.42 35.07 0.68 6 Indicated 9.233 2.975 10.32 0.40 39.96 0.72 Inferred 4.252 1.364 10.93 0.56 35.50 0.48 Total: 13.485 4.340 10.51 0.45 38.55 0.64 7 Indicated 6.953 2.223 11.58 0.43 42.85 0.64 Inferred 3.602 1.150 11.73 0.60 37.24 0.49 Total: 10.555 3.373 11.63 0.49 40.94 0.59 7.5 Indicated 6.100 1.943 12.18 0.45 44.82 0.60 Inferred 3.345 1.065 12.08 0.62 38.18 0.48 Total: 9.445 3.008 12.14 0.51 42.47 0.56 8.5 Indicated 4.784 1.512 13.34 0.46 47.34 0.52 Inferred 2.820 0.894 12.83 0.62 38.83 0.48 Total: 7.605 2.406 13.15 0.52 44.18 0.50 9 Indicated 4.179 1.316 14.01 0.45 48.07 0.49 Inferred 2.548 0.805 13.27 0.62 38.88 0.48 Total: 6.727 2.121 13.73 0.51 44.59 0.49 10 Indicated 3.233 1.009 15.33 0.45 50.99 0.46 Inferred 1.909 0.599 14.50 0.58 38.67 0.47 Total: 5.142 1.608 15.02 0.50 46.42 0.46 Comparison with previous estimates The new resource estimate represents a 6.5 times increase in contained metal compared to the previous estimate at the same cut off (1.23Mt compared to 0.19Mt of zinc metal). The previous estimate was based on extrapolating the thickness of mineralization in the underground trial mining to the rest of the deposit area. Once the geometry of the Chinese model was found to be incorrect, the resource could not be re-modeled reliability until a viable geological model could be demonstrated. The previously announced estimate was 1.52Mt @ 12.34% zinc, 0.53% lead, 48g/t silver and 0.75g/t gold at a 7% zinc cut-off. Other items of significance As an indication of the reliability of the new resource model, Micromine were asked to separately estimate the northern part of the deposit which included the recent east-west cross drilling, both with the new results and without them. The results of each run were within 3% of one another, which gives confidence that the new geological interpretation is correct. In the last announcement, attention was drawn to the possibility that a distinct part of the deposit may contain a gold resource which could be mined for separate processing. In order estimate this potential, Micromine was requested to run a gold estimate on the entire deposit within the zinc envelopes. It should be borne in mind that this estimate includes the gold in the zinc-rich mineralisation reported above and is based on only partial gold analyses as not all core samples have been analyzed for gold. Because of this, and also because the drill-hole spacing is very wide for estimating gold mineralisation, the resource is placed in the Inferred category. The results are shown in Table 2. Table 2. Caijiaying Zone III Inferred Gold Resource at various cut-off grades Gold Cut-Off in g/t Tonnes Grade in g/t Au Au 3 2,610,000 6.78 4 1,675,000 8.63 5 1,265,000 9.99 Conclusions • The new geological interpretation of the summer drilling results has at last enabled the Caijiaying mineralisation to be reliably modeled. • The new resource estimate that is based on the revised geological model has exceeded expectations and is 6.5 times the amount of contained zinc metal than the last reported estimate. • The size of the new resource estimate means that work on project mine planning can now proceed with confidence. • The previously proposed first stage, high-grade mine plan of a 180,000 tonnes per annum operation is still recommended as a first-stage choice as it will take time to develop the underground decline and mine headings. • The size of the new resource estimate gives considerable confidence that the mine throughput can be increased once the mine is sufficiently developed. • The size of the initial Inferred gold resource confirms that there is potential to also develop a separate gold recovery operation within the larger Zone III mine as a further upgrade to the project. This will best be defined by infill underground exploration from the zinc-mine decline. • The new resource model has also suggested that the Zone III mineralisation may continue a further 1km to the south and link up with the previously sub-economic Zone II deposit. If future exploration proves this to be the case, it will allow the option of further upgrades to the operation or a longer mine life. It is also believed that there is good potential for further gold discoveries in the area. Neither CSA nor Micromine Consulting nor any of their staff have any beneficial interest in Griffin other than the provision of ongoing professional fee-paying services. Signed _______________________ Rupert W. A. Crowe BSc, F.AusIMM, MIAEG Managing Director, CSA Australia Pty Ltd This information is provided by RNS The company news service from the London Stock Exchange
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