20th Aug 2012 07:00
Stratex International Plc / Index: AIM / Epic: STI / Sector: Mining
Stratex International Plc
('Stratex' or the 'Company')
West Africa Update: Multiple Prospects Identified in Senegal and Mauritania and Airborne Geophysical Survey Completed Over Dalafin Licence
Stratex International plc, the AIM-quoted exploration and development company operating in Turkey, East Africa and West Africa, is pleased to provide an update on the Company's recently acquired portfolio in Senegal and Mauritania. In Senegal, the Company is earning-in to 75% of the Dalafin Exclusive Exploration License (EEL) and has recently completed grassroots exploration including systematic sampling programmes and an airborne geophysical survey.
Highlights
·; Stratex now vested at 51% of Dalafin gold EEL in Senegal
o 636 sq km of highly prospective terrain in the centre of the Birimian Kédougou-Kenieba gold belt which extends from Senegal into western Mali and has already seen multiple major gold discoveries
·; Mineralisation identified in four key prospects within Dalafin licence - Konkonou, Baytilaye, Saroudia, and Madina Bafé
·; Multiple veins identified in Baytilaye and Madina Bafé prospects with best values to date of 5 m @ 3.79 g/t Au and 3 m @ 1.73 g/t Au in trenches and up to 18.6 g/t in samples from artisanal workings and lag samples
·; Mineralisation signatures (gold, tourmaline-cemented breccias, pyrite) similar to a number of multi-million-ounce gold deposits being exploited in the surrounding area
o Including Randgold Resources' Loulo deposit (12 million oz Au)
·; Airborne geophysical survey completed over entire licence - interpretation underway
·; Encouraging prospects identified in Mauritania
Commenting, Stratex CEO Bob Foster said, "We are very pleased with the rapid progress and successes achieved by our team working on the Dalafin project. Although it is still early days, a number of prospects have emerged from the regional soil geochemical survey and we are now undertaking infill soil sampling to narrow our focus on to specific targets. We have also identified multiple vein systems, some showing the characteristics of some of the major multi-million-ounce deposits that are now being mined in the surrounding area.
"Our airborne geophysical survey was completed just before the full onslaught of the rainy season. Consequently, once we have received the assay results from the substantial soil and rock sampling programmes that we have undertaken, we will be well-placed to refine our prioritisation of prospects with a view to further trenching and very probably drilling after the rainy season comes to an end in October. Intense leaching of the soil profile is a characteristic of the regional climatic regime and consequently even low gold values in soil and weathered rock (saprolite) may need to be investigated by drilling.
"Our early reconnaissance work in Mauritania has also led to identification of some early-stage targets comprising shear-controlled vein mineralisation hosted by a range of rock-types including banded iron-formation, which is a particularly good host for orogenic gold deposits. We will proceed with this smaller programme in parallel with our work on Dalafin."
Further Details
In January 2012, Stratex completed the acquisition of the entire issued share capital of Silvrex, a private company incorporated in the UK with a prospective gold portfolio in Senegal and Mauritania. The acquisition has provided Stratex with a significant foothold in West Africa, which is widely recognised as an important region for gold exploration.
Executive Director, John Cole-Baker (formerly Silvrex's Chairman and Managing Director), leads the established exploration team of three Senegalese geologists and one locally-based international consultant, supported on a part-time basis by Mr. Ed Slowey (formerly Silvrex's Technical Director), to accelerate the exploration programme in Senegal and Mauritania.
Senegal
Stratex's principal asset is the 636 sq km Dalafin EEL for gold, into which the Company is currently earning 75% under the terms of a joint venture with a private Senegalese company Energy and Mining Corporation s.a. (EMC). Located in south-eastern Senegal, Dalafin is positioned in the centre of the Birimian-age Kédougou-Kenieba gold belt that extends from eastern Senegal into western Mali and has already seen multiple major gold discoveries including Randgold Resources' Massawa deposit (3.4 million oz Au) and Oromin Exploration's Sabodala deposit (3 million oz Au) in Senegal, and Randgold's Loulo (12 million oz Au) and Gounkoto projects (5.76 million oz Au) in Mali. Of critical importance is the fact that a number of the gold-rich deposits in the general vicinity of the Dalafin licence are hosted by NNE-trending fault zones, some of which also transect the Dalafin area.
Initial work undertaken by Silvrex had targeted first-phase (reconnaissance) exploration on areas identified from a recent regional airborne geophysics programme completed by Fugro Airborne Surveys Ltd. and a regional soil survey completed by BRGM, a leading French geoscience institute, and also on areas discovered to be the focus of exploitation by artisanal (small-scale) workers. Stratex has almost completed a systematic sampling programme on these initial targets to test the extent and continuity of the gold mineralised zones.
One factor that renders the exploration of this area particularly problematic is the widespread occurrence of cuirasse, a hard crust of iron-cemented material, typical in tropical environments where heavy seasonal rainfall causes extreme downward leaching of most elements from the upper part of the soil profile with the exception of iron and aluminum. The cuirasse can extend from surface to depths of 2-3 m but is usually 0.5-1.0 m in thickness. To evaluate the mineral potential beneath these areas, the Company is using a combination of sampling techniques which include lag sampling, trench sampling and termite mound sampling - based on the recognition that termites excavate beneath the cuirasse in the search for moisture, often contained in fracture zones. Lag sampling is the collection of residual vein quartz material lying on the cuirasse surface and possibly indicative of in-situ quartz veins in the underlying bedrock.
To date, geological observations and sampling data have confirmed four main areas of interest, namely (from north to south) Konkonou, Baytilaye, Saroudia, and Madina Bafé. Key features emerging from the early evaluation of these areas are:
Konkonou
·; First targeted on the basis of gold-in-soil anomalies over an area of approximately 2,000 m x 200 m and a second less well-defined zone extending for a distance of at least 1,000 m
·; A number of artisanal pits have exposed quartz veins in siltstones and graphitic phyllites and also in quartz-feldspar-porphyry dykes; the latter commonly contain minor pyrite and molybdenite. Numerous fragments and clasts of vein quartz also occur in the overlying cuirasse
·; An initial pitting programme by the Company has revealed persistent but low gold anomalies with a maximum of 0.117 g/t Au
·; A programme of termite mound sampling and lag sampling has been completed across the perceived north-eastern extension of the gold-in-soil anomaly, extending for a further 3,000 m - assay results awaited
Baytilaye
·; A broad but ill-defined zone, up to 400 m wide and extending for at least 1,000 m in a north-north-east direction, encompasses a number of exposures of vein quartz that are being trenched and sampled in the north-western part of the prospect
·; One significant 5 m-wide quartz vein is hosted within graphitic sedimentary rocks and assayed 3.79 g/t Au. The vein strikes NNE to NE, similar to a number of the major discoveries in the region
·; Trenching within the zone has returned multiple values >0.1 g/t Au, with a maximum of 1.23 g/t Au
·; Further to the north-east, and beyond the area defined by the gold-in-soil anomalism, a zone of shearing containing deformed lenses and veins of tourmaline-bearing quartz has been discovered and early work suggests that it extends for as much as 5,000 m in a NE-SW direction
·; Another occurrence of vein-quartz lag material with some in-situ vein quartz has been identified elsewhere in the north-eastern part of the prospect and covers an area of 15-20 m N-S and 2-3 m E-W.
·; Two veins have also been located where they protrude above the cuirasse horizon that forms a prominent elevated area in the north-east sector
Saroudia
·; Pitting has been completed across a previously identified gold-in-soil anomaly in the western part of the prospect, with best results of 0.332 g/t Au and 0.233 g/t Au in adjacent pits 20 m apart
·; A north-east-trending zone of quartz veining in iron-rich tuff has been discovered some 200 m east of the above target area Follow-up trenching of the pitted area returned a maximum value of 0.181 g/t Au, although a grab sample of outcropping material assayed 1.82 g/t Au
Madina Bafé
·; 5 m-wide quartz vein has been exposed by trenching in the north-west part of a wide area previously defined by gold-in-soil anomalies. Multiple associated narrower veinlets host pyrite and minor chalcopyrite. Maximum assay result to date is 3 m @ 1.73 g/t Au
·; Parts of the above-vein system comprise quartz breccia cemented by tourmaline. Tourmaline is a prominent component of the mineralised zone in Randgold's nearby Loulou deposit in Mali
·; The vein system has been traced for almost 100 m south-eastwards. A further quartz vein has been discovered some 250 m south-west of the first vein and an initial grab sample has returned 0.38 g/t Au
·; Quartz veins containing minor pyrite and tourmaline observed in rubble around artisanal pits in the same area
·; Fine grained quartz-feldspar-porphyry observed locally, containing fine networks of quartz veinlets. A line of artisanal pits trending NE-SW in the porphyry was sampled and grab samples all returned anomalous values with a maximum of 0.38 g/t Au
·; A further mineralised zone has been discovered some 800 m south-east of the earlier discovery and is now the focus of intensive artisanal working with free gold being panned from the workings. The zone is approximately 5 m in width and contains both vein quartz and tourmaline-cemented breccia. A sample taken from an artisanal pit at depth returned a value of 18.6 g/t.
·; A third vein has recently been identified approximately 2 km south-west of the first discovery and has been traced for at least 300 m. Width is difficult to estimate because of poor exposure but is described as "considerable".
·; 2 km SE of this vein a grouping of lag samples returning between 2.84 and 17.7 g/t may indicate a further target in this area.
A large number of samples from the above prospects have been submitted for assay, together with more than 2,000 infill soil samples from Baytilaye and two further areas, Madina Southeast and Dalafin North. Results will be reported when they become available.
The Company has also completed an airborne geophysical survey (magnetics and radiometrics) across the entire licence, at a line spacing of 100 m and flown at an approximate elevation of 50 metres. Interpretation of this high-resolution data is underway and will facilitate prioritisation of the prospects already discovered as well as providing a focus for further exploration in the licence area. Reconnaissance drilling is provisionally planned to commence once the current rainy season has ended - usually late October.
The total expenditure on the licence has now exceeded US$1.5 million and Stratex is now vested at 51% of the Dalafin joint venture, with the option to spend a further US$1.5 million to acquire an additional 24%, for a total of 75%.
Mauritania
The Company's portfolio in Mauritania comprises four licences that have been the subject of study using remote sensing imagery followed by reconnaissance visits by Stratex to areas of interest. Mapping and outcrop sampling has commenced on the Azrag licence and a number of interesting targets have been identified, predominantly quartz veining and hydrothermal replacement associated with shearing of banded iron-formation rocks, which is a particularly good host for orogenic gold deposits. Samples have been submitted for assay. Reconnaissance visits to the other three licences will be undertaken in due course to provide a focus for future exploration.
For more information on our West African projects, please visit:
http://www.stratexinternational.com/operations/exploration/west-africa.aspx
Glossary of Technical Terms
"Au" chemical symbol for gold
"banded iron formation" iron-rich rock that shows marked banding, generally of iron-rich minerals and chert or fine-grained quartz
"breccia" rock composed of sharp-angled fragments embedded in a fine-grained matrix
"dyke" a tabular body of intrusive igneous rock emplaced vertically or at a steeply inclined
angle to the horizontal and usually cross-cuts the host rock
"g/t" grammes per tonne, equivalent to parts per million
"orogenic gold deposits" formed from hydrothermal solutions at depths of between 6,000 and 20,000 metres in the temperature range of 300-550 °C. Among the common ore minerals in these deposits are gold, pyrite, chalcopyrite and galena
"oz" troy ounce (= 31.103477 grammes)
"phyllite" a regional metamorphic rock derived from clay-rich sedimentary rocks. Characterized by lustrous, often undulating, well-developed cleavage surfaces, often light silvery-grey in colour.
"porphyry" an igneous rock in which relatively large crystals (phenocrysts) constitute 25% or more of the volume and are set in a fine-grained ground mass. Can also be used in conjunction with a mineral/metal name where the rock is rich in that component, e.g. quartz-feldspar porphyry
"shear zone" a tabular zone of rock showing evidence of shear stress i.e. a stress field that is acting parallel to a plane passing through any point in the body
"siltstone" fine-grained sedimentary rock principally composed of silt-grade material, in the range 0.004 to 0.062 millimetres
"tuff" rock composed mainly of volcanic ash (fragments more than two millimetres in diameter) ejecta
Sampling, assaying, and QA/QC
Stratex's sampling of outcropping rocks, drill core, and other geological materials conforms to industry-wide good practice, with chain of custody being observed for all samples. Gold analysis is undertaken by ALS Chemex at its laboratories in Mali and the Company maintains QA/QC on all analytical work via the use of certified reference materials, preparation duplicates, field duplicates, and blank samples in addition to monitoring of internal laboratory check-analyses.
Dr Bob Foster, CEO, is a Competent Person as defined by various international instruments and takes responsibility for the release of this information.
* * ENDS * *
For further information please visit www.stratexinternational.com, email [email protected], or contact:
Stratex International Plc | Tel: +44 (0)20 7830 9650 |
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Bob Foster / John Cole-Baker / Claire Bay
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Grant Thornton Corporate Finance | Tel: +44 (0)20 7383 5100 | |
Gerry Beaney / Melanie Frean
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Northland Capital Partners Limited | Tel: +44 (0)20 7796 8800 | |
Gavin Burnell / Tim Metcalfe John-Henry Wicks / John Howes (Sales)
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Newgate Threadneedle | Tel: +44 (0)20 7653 9850 | |
Josh Royston / Beth Harris |
Notes to editors:
Stratex International is an AIM-quoted exploration and development company focussed on gold and high-value base metals in Turkey, East Africa and West Africa. Since listing on AIM in 2006, Stratex has had an impressive track record of successful exploration supported by joint-venture partnerships, both with major international mining companies and local companies to maximise the potential of its discoveries.
It currently has a substantial portfolio of projects, with two in Turkey that are scheduled for gold production in 2013. To date Stratex has discovered more than 2.2 million ounces of gold and 7.9 million ounces of silver, as well as 186,000 tonnes of copper.
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