10th Apr 2008 08:19
Berkeley Resources Limited10 April 2008 10 April 2008 INITIAL DIAMOND DRILLING AT GAMBUTA CONFIRMS SIGNIFICANT SHALLOW URANIUM MINERALISATION The Directors of Berkeley Resources Limited (AIM: BKY.L) are pleased to provideinitial results of the first stage program of diamond and RC drilling at theGambuta prospect in Caceres Province, Spain. Four diamond core holes have been drilled to twin historical roto-percussionholes within a north-east trending area of 900m by 400m. All four holes haveintersected significant shallow uranium mineralisation. Assays for the firstthree holes completed include: Hole GAM-001 8.0 metres @ 0.0586% U3O8 from 0.0m Hole GAM-002 12.5 metres @ 0.0741% U3O8 from 0.0m and 4.0 metres @ 0.0997% U3O8 from 28.0m Hole GAM-004 17.7 metres @ 0.0292% U3O8 from 11.5m, including 7.0 metres @ 0.0431% U3O8 from 14.5m The third hole (GAM-003) was terminated at 36m and has subsequently beenre-drilled to 64.6m. Down hole radiometrics for the completed portion of GAM-003shows similar peaks to the other 3 holes and assays are awaited. These results confirm the presence of extensive, near surface uraniummineralisation, at potentially economic grades, and provide substantialencouragement at the beginning of Berkeley's program to drill test historic andnew targets within the Caceres VI licence. The Gambuta prospect was previously drilled by CISA (a joint venture betweenAreva and ENUSA) in the early 1990's. That campaign of 24 roto-percussion drillholes, together with Berkeley's radiometric surveys, has now defined extensivemineralisation within an area of 900m by 400m. This mineralisation is likely tocontinue beneath Tertiary cover, both within the area and along strike. A Reverse Circulation drilling program to test the broader extent of the anomalywill commence shortly. Enquiries - Managing Director: Matt Syme Tel: +61 417 906 717 RBC Capital Markets: Martin Eales Tel: +44 20 7029 7881 Background The Gambuta project is located 6kms to the west of Bohonal de Ibor in theextreme west of Berkeley's Caceres VI licence. This licence contains a number ofperigranitic uranium mineral occurrences of which Gambuta is a typical example.Other prospects include El Zarzal and Ojaranzo, located in the central andeastern part of the tenement respectively. The initial discovery of uranium mineralisation at Gambuta was made by the JuntaEnergia Nuclear ("JEN") during the 1960's. Follow up by CISA (a joint venturebetween ENUSA, the Spanish State uranium company, and COGEMA, the French companynow called AREVA) during the early 1990's included a program of geologicalmapping, detailed ground radiometrics and trenching (11 totalling 240m), whichhelped target a program of 24 roto-percussion drillholes (1721.8m). CISA records indicate that 21 of these 24 holes encountered significantlyanomalous radiometrics in the downhole logs, which they believed equated touranium mineralisation. CISA's radiometric and geological logs broadly definethe magnitude and tenor of the anomaly and differentiate between intrusive andmetasedimentary material and the degree of weathering. Only summarized downholegamma readings are available. No chemical assays were completed. Severalhistoric drill collars have been located and their positions are withinacceptable limits (1-2m). CISA identified a north-westerly trending mineralised structural zone withdimensions of approximately 900m x 400m, including an area of untested Tertiarycover in the central area. Aerial Survey In late 2007 Berkeley completed a helicopter-borne radiometric and magneticsurvey over the Caceres VI licence to better define the extent of the knownuranium occurrences and to identify potential extensions and possible newoccurrences. The survey comprised 1,468 line kilometres on 100m spaced north - south linesusing a towed magnetic sensor at a nominal height of 35m and a spectrometerinside the aircraft. The survey specifications, supervision, quality control anddata interpretation were undertaken in conjunction with Berkeley's seniorgeophysical consultant, Bob White. The results show the Gambuta uranium mineralisation to occur adjacent tothorium-rich, differentiated granite with potential for significant extensionsto the South East along the granite margin. The Gambuta radiometric anomaly appears to be blanketed by Tertiary cover whichextends to the north and west into areas where the magnetics suggest east-north-east orientated structures in the underlying granitic body. The northernportion of the Gambuta anomaly increases in strength towards the northern mostcontact with the Tertiary. A magnetic anomaly also occurs under the cover and magnetic features areassociated with uranium mineralisation in most areas. Berkeley Drilling Four angled diamond core holes have been drilled to test the results ofhistorical percussion drilling and to clarify geological and structural controlson the mineralisation. TABLE 1. BERKELEY RESOURCES DRILL DETAILS and INTERSECTIONS (200ppm cut-off) HOLE_ID UTM_E (m) UTM_N (m) RL Inclination EOH From To Interval %U3O8 GAM-001 291,730 4,404,118 387 -60 to 000 103.0 0.0 8.0 8.0 0.0586 10.0 11.0 1.0 0.0218 19.0 20.0 1.0 0.0512 34.0 35.5 1.5 0.0301 37.5 38.5 1.0 0.0389 45.0 46.0 1.0 0.0768 55.0 56.0 1.0 0.0343 58.5 59.5 1.0 0.0338 GAM-002 292,381 4,403,899 369 -60 to 000 85.0 0.0 12.5 12.5 0.0741 21.5 22.5 1.0 0.0312 24.0 25.0 1.0 0.0394 28.0 32.0 4.0 0.0997 34.5 35.5 1.0 0.0340 GAM-004 292,368 4,403,828 353 -70 to 180 61.7 11.5 12.3 0.8 0.0218 14.5 21.5 7.0 0.0431 22.5 23.5 1.0 0.0397 24.5 25.5 1.0 0.0531 27.0 29.2 2.2 0.0256 34.0 35.0 1.0 0.0285 The Grid has a datum of UTM 30N ED50. These results confirm the significance of the results obtained in the previousCISA roto-percussion drilling and indicate the potential for extensive shallowmineralisation. A program of Reverse Circulation (RC) drilling will be undertaken in the JuneQuarter to further test the continuity and extent of the mineralised system. Geology A basement of thermally altered Cambrian to Precambrian metasediments(originally shales and greywackes) has been intruded by numerous aplitic dykesclose to the western contact of an extensive Hercynian granite batholith.Tertiary cover of clays, sands and gravels has been partially removed by recenterosion to expose windows of poorly outcropping metasediments with near-surface,litho-structurally controlled uranium mineralisation. Although no primary mineralisation has been observed, high radiometric valuesare associated with closely spaced sub-vertical shears and fractures, often withpyrite grains aligned sub-parallel to the main cleavage (110-1200). A geneticmodel, similar to that developed for the Retortillo deposit, appears to alsoapply at Gambuta; where oxidized ground waters carrying dissolved uraniumspecies come in contact with a reducing metasedimentary package, resulting indeposition of the uranium as pitchblende and coffinite. Secondary autunite wasnoted on fracture surfaces in the GAM-002 drill pad. Radiometric anomalies coincide with topographic lows where Tertiary cover hasbeen eroded. Further, the radiometric lows coincide with topographic highs andintact Tertiary cover. The strike of the two areas of radiometric highs coincides with the geologicalstrike and therefore continuity of mineralisation beneath Tertiary cover is verylikely. Interestingly, the highest grade mineralisation at Retortillo occursbeneath such cover. This information is provided by RNS The company news service from the London Stock ExchangeRelated Shares:
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