28th Feb 2007 07:01
Medusa Mining Limited28 February 2007 MEDUSA MINING LIMITED Co-O MINE DEEPS DRILLING YIELDS MULTIPLE HIGH GRADE INTERSECTIONS AND CONFIRMS CONTINUITY WITHIN THE 1.5KM LONG VEIN SYSTEM Medusa Mining Limited ("Medusa" or the "Company"), the Australian based companyoperating and developing gold mines in the Philippines, advises that it hasintersected several high grade veins during recent drilling confirming depthextensions within the the 1.5km long Co-O vein system and that undergroundsampling has also returned continuous high grade results over a considerablestrike extent. • Results from the first four drill deep holes have returned results including 1.5 metres at 16.75g/t Au, 4.7 metres at 57.66g/t Au, 1.55 metres at 15.23g/t Au, 1.4 metres at 14.77g/t Au and 0.55 metres at 21.47g/t Au; • Compilation of the 3,050 metre level (current mine bottom) development sampling shows the Central Vein contains continuous mineralisation averaging: 35.37g/t Au (uncut) over a strike length of 267 metres with an average width of 1.4 metres and open to the east and the west. DRILLING RESULTS Programme description The Company commenced a drilling programme designed to intersect the Co-O Minevein system at approximately 100 metres below the current bottom of the mine(level 2,950 metres) which is approximately 200 metres below the adit to themine (level 3,150 metres). Holes are being spaced at approximately 50 metreintervals along strike, but the intersection depth and position of each drillhole is dependent on topographic constraints. Two deeper drill holes atapproximately 250-300 metres vertically below the adit level have also beencompleted. Each drill hole has been surveyed every 50 metres downhole using amultishot digital camera. The first four holes have been completed and drilling will continue forapproximately another 3-4 months. Intersections of >4g/t Au from the drilling are presented in Table I. The lowergrade intersections are included because of the variability of grades within theveins and because they define gold mineralised veins requiring furtherinvestigation. It is important to note that drilling of narrow epithermal veins at bestgenerally provides only an indication of the presence of the gold mineralisedvein and rarely provides good quantitative data with respect to accurate gradeand volume estimations for some or all of the following reasons: • Veins commonly pinch and swell and may be brecciated or displaced by faults; • Gold distribution is commonly erratic, in shoots or controlled by structures within the vein; and • Drill core recovery can be reduced because of the brecciation and soft unconsolidated material and hence the recovered material may not be representative of the material drilled. Consequently, the Company regards the initial drilling as indicative only andoperates the policy of using drilling to locate the extent of the mineralisedveins. This is then followed by level development to support the drillingresults, to provide a more accurate estimate of vein grades and to facilitatethe estimation of resources. Table I: Summary of drilling results for holes MD 20 to MD 24 for intersection grades >4g/t Au Hole East North Dip Azimuth From Width Grade (degrees) (degrees) (m) (m) (uncut) g/t gold MD 20 614099 913092 -51 214 230.10 1.50 16.75 250.25 0.85 4.22 265.90 0.45 7.19 290.70 0.60 4.92 311.40 4.70 57.66 323.10 1.70 15.76 333.10 1.50 4.65 337.05 4.55 6.98 352.20 0.80 11.41 359.60 0.80 4.14 361.55 1.55 15.23 381.95 0.35 15.56 MD 21 614120 913134 -50 214 41.40 0.70 13.53 185.90 1.80 5.04 Hole Stopped At 268.10m MD 23 614120 913134 -56 214 45.20 1.70 8.30 190.80 1.40 14.77 349.10 0.40 7.98 MD 22 614025 913188 -45 210 135.50 0.55 30.95 161.60 0.30 14.50 324.15 0.65 8.78 360.80 4.80 8.19 MD 24 614026 913190 -55 210 281.25 0.55 21.47 357.75 1.25 12.38 407.60 0.60 4.76 Note: McPhar Geoservices Inc. assays are quoted in preference to the Companylaboratory's assays. Co-O Vein System Discussion The Co-O Mine vein system trends westerly and is truncated by a majornorth-trending fault (the Oriental Fault) which has vertically downthrown thevein system on the eastern side of the fault by an estimated 300 metres andmoved the veins horizontally by approximately 20 to 40 metres, with the eastside moved to the south. The effect of the downthrow is that the Co-O veins onthe east side of the fault are not exposed at surface and the tops of the veinsappear to commence approximately 160 metres below surface and below the aditlevel. When the mine was originally developed in the late 1980s, the vein system hadonly been discovered on the west side of the Oriental Fault (despite explorationdrilling on the east side) and all mine development was carried out on the westside over approximately 600 metres of strike length. Drilling, which commencedin late 2004 (holes MD 1-8), intersected the vein system on the east side of theOriental Fault and subsequently delineated the vein system over a strike lengthof approximately 250 metres to east. Subsequent underground development hasverified the intersection grades and widths in holes MD 1-4 over a strike lengthof 104 metres which is open to the east. Development on veins within the mine on the west side of the Oriental Fault overa strike length of over 600 metres indicates the vein system is open to thewest, and drilling and mapping to the east of the Oriental Fault havedemonstrated that the Co-O Vein system is still open to the east and isdemonstrated to be over 1.5km in length. New Drilling East of the Oriental Fault Results are contained in Table I. MD 20 intersected multiple veins hosted by altered micro-diorites, porphyriticandesites and andesitic volcanics. The high grade veins (up to 4.7 metres @57.66g/t Au) are commonly colloform banded and vuggy, contain 0.5 metres at >2g/t Au were re-assayedby McPhar Geoservices Phls Inc ("McPhar"), a NATA registered laboratory inManila. The pulps were airfreighted to McPhar who fire assayed 30 grams ofsample using AAS finish and a selected number of samples were checked usinggravimetric fire assay techniques. When reporting results, where available, the McPhar assays have given priorityover the Company laboratory's results. 3,050 METRE DEVELOPMENT ASSAYS Compilation of the Central Vein assays from mine development on the 3,050 metrelevel (currently the bottom of the mine at the bottom of the newly completed 3Wshaft) shows that the combined continuous high grade mineralisation on each sideof the Oriental Fault totals a strike length of 267 metres with an average gradeof 35.37g/t Au (uncut) and with an average width of 1.4 metres. Over a considerable amount of the strike on the west side of the Oriental Fault,the development is completely within the vein and information from developmentabove and below the level indicates that there is generally between one and twometres of vein still in the north wall of the 3,050 metre level drive. Theadditional material in the north wall is not included in the average width of1.4 metres. Geoffrey Davis, Managing Director of Medusa, commented: "These results firmly support our view that the Co-O Mine will develop into anexceptionally high grade gold mine with potential for a considerably enhancedresource base. On completion of the drilling programme, an updated resourceestimate will be undertaken in areas where sufficient data density isavailable." Maps and cross sections which accompany this announcement can be viewed in theASX version of the announcement on the Company's website:www.medusamining.com.au The information in the above announcement was compiled by Geoff Davis, who hassufficient experience which is relevant to the style of mineralisation and typeof deposit under consideration and to the activity which he is undertaking toqualify as a Competent Person as defined in the 2004 Edition of the"Australasian Code for Reporting of Exploration Results, Mineral Resources andOre Reserves". Geoff Davis consents to the inclusion in the report of thematters based on his information in the form and context in which it appears. Reference Cube Consulting Pty Ltd, 2004: Co-O Gold Project. Resource Estimate Dec. 2004.Internal Company Report. 27th February 2007 For further information, please contact: Medusa Mining Limited +61 8 9367 0601Geoffrey Davis, Managing DirectorRoy Daniel, Finance Director Ambrian Partners +44 (0)20 7776 6417Richard Brown / Richard Greenfield Bankside Consultants +44 (0)20 7367 8888Michael Padley / Daniela Hale This information is provided by RNS The company news service from the London Stock ExchangeRelated Shares:
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