Zambezi Resources gives quarterly report

Tag : Thin Section Bearing

Coordinate system Arc50 UTM Zone 35S. Mineralised intervalscalculated on basis of lower cutoff of 0.3% Cu, minimum mineralisedinterval of 0.5m, maximum internal waste of 1m. Mineralisedintervals >3m% copper reported here. No cut applied to goldvalues. At CC2, mineralisation dipping to north at 50-55 degrees.Mineralised widths reported on downhole basis, true widthapproximately downhole width x 0.9 . For all other prospects,mineralised widths reported on downhole basis, true widths not yetestablished. CHERC prefix denotes RC drillholes, CHEDD prefixdenotes diamond drillholes.
At the 100% owned Kangaluwi Copper Project, RC drilling carried outin 2007 has returned significant copper mineralisation oversubstantial widths in multiple zones (Table 3, Figs 3, 4, 5).Results include 18m at 1.42% copper from 114m, 17m at 1.24% copperfrom 49m, 10m at 1.97% copper from 30m, 15m at 0.86% copper from39m, 10m at 0.86% copper from 112m, 10m at 0.83% copper from 6m,and 18m at 0.63% copper from surface. Diamond drilling carried outin 2007 has confirmed down dip continuity of mineralisation (Table3, Figs 3, 4, 5). Results include 19.2m at 1.14% copper from 92m,8.07m at 2.98% copper from 145.34m, 6.14m at 1.29% copper from157.68m, 7.32m at 1.40% copper from 161m, 5.46m at 1.66% copperfrom 108.54m, and 6.43m at 1.02% copper from 125.98m.
Two other prospects at Chisawa and Kalulu have been tested to dateby limited drilling in 2006 and 2007, respectively. Initial resultssuggest that mineralisation at these prospects is similar to thatencountered at Kangaluwi. These will be tested in 2008 along withthe currently untested Imboo prospect and two newly identified soilgeochemical copper anomalies, which are all of equivalent tenor tothe initial Kangaluwi soil geochemical anomaly, and are consideredhighly prospective.
Re-establishment of road access to the project after the wet seasonwas completed and drilling re-commenced during mid May. The 2007drilling campaign initially focused on 3km of strike length atKangaluwi, which was later narrowed down to an 800m section drilledto a 50m by 50m pattern. The Company chose to intensively drill asmall area in order to evaluate the possible economic potential ofthe mineralisation. Due to the encouraging results from thisdrilling, the Company has decided that the mineralisation hassufficient potential to justify a much more extensive drillingprogram at Kangaluwi and on the remaining five zones identified.The 2008 RC and diamond drilling program utilising up to sixdrilling rigs is designed to test the strike and down dipextensions of copper mineralisation at the Kangaluwi prospect, andto follow up encouraging preliminary results from Kalulu andChisawa. To 30 June, 67 RC and diamond holes were completed for atotal of 12,155m at Kangaluwi, and 28 RC holes were completed for atotal of 4,641m at Chisawa. Further encouragement has been receivedfrom recent drilling with excellent continuity both down dip andalong strike. Assay results are awaited.
Mineralisation at Kangaluwi consists of chalcopyrite, bornite,malachite and azurite with chalcopyrite being the dominant oremineral in fresh rock at depth. The host rocks consist of shearedand brecciated metasediments and metavolcanics. Mineralisation dipsmoderately to the south west at approximately 30-40o and occurswithin the sheared northern limb of an overturned ESE- plungingregional synformal fold. Mineralised zones average approximately10m in thickness, with some broader zones of up to 32m inthickness. Drilling also suggests the potential for multiplemineralised zones which broaden at depth
Preliminary metallurgical testwork on composite 2007 drill corefrom Kangaluwi has indicated favourable metallurgicalcharacteristics. The ore is relatively soft with a Bond Mill WorkIndex of 11.5 kWhr/t, and a Rodmill Work Index of 8.9 kWhr/t. Thisis based on a single composite test. The first rougher flotationtest showed recoveries in excess of 95% copper and silver which arethe only metals expected to be of economic value for the KangaluwiProject. A set of more comprehensive metallurgical tests will beundertaken commencing in September 2008.
The application of modern geophysical techniques such as highresolution aeromagnetics and VTEM has proved to be an importantexploration tool for Zambezi. During the Quarter, the Companycompleted a major regional VTEM survey comprising a total of 1,780line kms at Kangaluwi, in an attempt to delineate mineralisedcopper sulphide conductors and assist in drill targeting. Thesurvey was flown at a line spacing of 150m, with infill to 75m overthe Kangaluwi-Chisawa area, and covered all the identified soilgeochemical anomalies, and additional prospective lithologies northand north west of the Kangaluwi Prospect. A persistent and discreteelectrical conductor was defined at the Kangaluwi Prospect. Theposition of this conductor suggests that it may represent adown-dip and down plunge extension of the copper-mineralisedstratigraphy previously defined by soil sampling and drilling tothe north and west of the VTEM anomaly. Computer modelling wascompleted and suggests that there are two conductors, the mainconductor extending from near surface to a considerable depth belowsurface, dipping shallowly to the southwest and plunging at 10degrees to the east. Subsequent to the Quarter, the Companycommenced drilling to test the conductors. Two diamond holes havebeen completed, but to date only minor sulphidic or graphiticlithologies have been intersected. Computer modelling of the newdata is underway to determine whether these lithologies may beresponsible for the VTEM conductivity. The holes are being cased toenable downhole EM to be run if considered necessary.
PROJECT GENERATION
Extensive high resolution helimagnetic and radiometric surveyscommenced in Q4 2007, and were completed in Q2 2008 over the MpandeLicence. Data processing and interpretation is underway.
An airborne VTEM geophysical survey was completed at the Mulofweproject (see Fig 1) to refine and identify further drill targets.An outstanding late time electrical conductor was defined atMulofwe, with computer modelling suggested that the VTEM responsewas consistent with the presence of a conductor or conductorsdipping shallowly to the south and east at between 5 and 25degrees, with a core zone of some 3 square km in area. Drillingcommenced on 9 June to test the VTEM conductors. Three diamondholes were completed for 522.1m. MDGDD0001 (710290E 8312456N, totaldepth 130.1m) intersected graphitic schist from 68.0m to 81.10mwith up to 1% disseminated pyrite along foliation and fracturesurfaces. MDGDD0002 (710496E 8312142N, total depth 250m) alsointersected graphitic schist from 159.03m to 173.32m with up to 1%disseminated of pyrite. MDGDD0003 (708801E 8312299N, total depth125m) intersected a thin graphitic schist from 91.34m to 93.78mwith traces of pyrite. The VTEM anomaly has been demonstrated to bealmost certainly due to the presence of graphitic schists. Sampleswill be submitted for gold analysis.
At the Mukwizi Copper Gold Project (see Fig 1), rock chip samplingon a 200 x 50m grid has returned values of 11.4% copper and 1.8 g/tgold, 4.8% copper and 0.4 g/t gold, and 4.0% copper and 0.9 g/tgold. Malachite, azurite, chalcopyrite and bornite have beenidentified at surface within an intensely fractured and brecciatedassemblage of ferruginous altered carbonate, calc-silicate andamphibole schist lithologies. No known trenching or drilling hasbeen identified in this area. Further work is underway to identifydrill targets.
At the Mvula Copper Gold Project (see Fig 1), soil sampling on a200 x 50m grid and resampling of historic trenches has confirmedsignificant copper and gold anomalism identified by previousexplorers. The anomalous north-west striking zone occurs within asimilar assemblage to that seen at Mukwizi and is defined over astrike length of 6 km. The zone is open at both ends and includes acore zone of 1 km at greater than 800 ppm copper, with peak valuesof 0.4% copper. Results from resampling of historic trenches fromthis anomalous zone include 23m at 0.43% copper, 11m at 0.45%copper and 7m at 0.56% copper. The entire strike length of 6 km hasonly been sparsely tested by 10 shallow historic diamonddrillholes, generally to vertical depths of less than 90m. Theseholes reportedly intersected patchy sulphides and returned valuesof 0.2 to 1% copper over intervals of 0.5 to 8.5m. Further work isunderway to identify drill targets.
GOLD PROJECTS
Following a review of the Company's 100% owned gold projects, andthe continuing strength of the US dollar gold price, Zambezi haselected to retain all its gold projects. Zambezi has completeddetailed helimagnetic and radiometric surveys at Mulungushi, Mpandeand Chumbwe East. Results from 2007 exploration work includingextensive soil, trench and rock chip geochemical sampling programsat pipeline projects Mulungushi and Mpande, and for 2007-2008 RABand RC drilling at Mulungushi, are currently being compiled, inorder to prioritise follow up exploration work.
URANIUM PROJECTS
Extensive high resolution helimagnetic and radiometric surveys inconjunction with joint venture partners Lithic Metals and EnergyLimited ("Lithic") have now been completed over the Mulungushi,Mpande and Chumbwe licences. These surveys were designed to extendhigh resolution geophysical coverage into these uranium projectareas, and provide vital information on the structural,lithostratigraphic and radiometric framework of the projects. Dataprocessing and interpretation is underway.
Lithic, as JV managers, completed a total of 9,051m of newtrenching at the Oryx prospect, testing peak uranium radiometricanomalies along a 2km strike length. Geological mapping andscintillometer logging of trenches identified visible in-situdavidite for the first time in association with high gammaradiation readings. Numerous other zones of elevated scintillometerreadings were noted without visible davidite. To assist in thecalibration of field scintillometers, 100 samples were collectedfrom zones of background to elevated scintillometer readings fromthree adjacent trenches and dispatched for analysis. This initialsampling programme revealed uranium mineralised intervals including3m at 642 ppm U3O8, 3m at 292 ppm U3O8, 1m at 839 ppm U3O8 and 1mat 272 ppm U3O8. Assay results from comprehensive sampling of zonesof elevated scintillometer readings are awaited.
Following the identification of uranium mineralisation intrenching, 11 diamond drillholes for 1,101.64m was completed,testing the down-dip extension of these davidite occurrences.Drilling intersected multiple zones of elevated scintillometerreadings in association with the presence of a mineral interpretedto be davidite. Drill core has been sampled and submitted foranalysis in conjunction with selected samples collected forconfirmatory petrology. Assays are awaited.
Subsequent to the Quarter, the Uranium Mineral Rights joint venturewith Rio Tinto at the Mulofwe project (see Fig 1) announced theidentification of several electromagnetic conductors within aregional shear zone interpreted to form part of the continent-scaleMwembeshi Shear system, following the completion of a major VTEMsurvey The shear zone is evident in electromagnetic and radiometricdata over a strike length in excess of 30km, and continues beyondthe survey boundary to the east and west. Preliminaryinterpretation suggests that the conductors are associated with theposition of a regionally extensive graphitic shale unit. Previousradiometric surveys carried out by Zambezi have highlighted uraniumanomalism believed to be associated with this unit. Geophysicalmodelling has been carried out on the eastern-most conductor withinthe shear zone. The modelling suggests the presence of a conductorof approximately 2km strike length dipping about 60o to the northand plunging gently to the east. The joint venture plans to conductfollow up work to investigate the potential for an associationbetween the conductive graphitic shales, the uranium radiometricanomalism and potential uranium mineralisation. This work willcommence in Q3 2008 under the management of Rio Tinto as jointventure operators, and will comprise trenching, geological mapping,PIMA surveying and drilling. In order to maximise the chances ofsuccess for the project, the joint venture partners have agreed toextend the area of the joint venture to cover the entirety of theprospective stratigraphy. This will be under the same terms of theexisting Uranium Mineral Rights agreement.