Location and Background
The Kiaka Project is located in south central Burkina Faso, approximately 120 kilometers southeast of the capital Ouagadougou. The closest town is Gogo, approximately 15km from the provincial capital of Manga.
The Kiaka Project lies at the intersection of the northeast striking Tenkodogo greenstone belt and the regionally significant north striking Markoye Fault, in whose proximity some of the larger gold resources discovered in Burkina Faso so far, have been discovered. These include Iamgold's Essakane deposit (5.1 M oz), High River Gold's Taparko deposit (1.7 M oz), Orezone's Bombore deposit (2.1 M oz) and Etruscan's Youga deposit (1.5 M oz).
The Kiaka Project includes the Kiaka gold deposit acquired from Randgold Resources in October 2009 for a consideration of 20 million shares of Volta Resources and C$4 million payable in 4 tranches at 6 month intervals commencing 6 months after transfer of the Kiaka license to Volta.
The Kiaka exploration permit covers an area of 244 km2, and was guaranteed to Randgold Resources on 17th June 2004 for a period of 3 years by aręte No2004/00/083/ MCE/SG/DGMGC. On 13 August 2007 the permit was renewed for the first time for a period of 3 years by the aręte No2007/ 07/116/ MCE/SG/DGMGC. The permit will be due for renewal again in June 2010 for another 3 years subject to the reduction of 25% of the present permit area. The license is currently being transferred to a wholly-owned Burkina Faso subsidiary of Volta Resources Inc., Kiaka Gold SARL. A local company (GEP Minerals) owns a 10% interest which is carried to the feasibility stage, whereafter they will participate with Volta assisting GEP to secure project financing.
Volta has commenced an aggressive drilling program comprising >22,000 meters in order to produce a NI43-101 compliant resource that will facilitate fast tracking the project toward a development decision.
Geological Setting
The Kiaka project is located at the intersection of the regionally significant Markoye Fault corridor and the Tenkodogo Belt, one of the 2300 -- 2180 Ma Birimian greenstones belts that are host to several world-class gold deposits in West Africa (see Figure1). Significantly, the Essakan, Bombore, Taparko and Youga deposits all occur close to the Markoye Fault.
From west to east, the lithologies at Kiaka are dominated by intercalated quartz mica garnet schist, quartz feldspar schist, amphibolites, quartz biotite schist and localized graphitic units. These are fine to medium grained metamorphic rocks after pelitic or semi-pelitic sediments origin, which was regionally metamorphosed in the amphibolites facies and later retrogressed under lower green schist facies. The lithologies are predominantly NE trending and are intruded by deformed porphyries and some gabbroic bodies in the northern and southern parts of the system. Late mafic sills like bodies intruded the middle of the target. These late intrusives are none-deformed, un-mineralized and introducing some waste material within the ore zone.
Mineralization
The controlling structures are predominantly oriented NE and sub parallel to the geology. Frequent micro folds fabrics, structural measurements and stereographic plots indicated that the target is associated with tight folds system and shearing. The schistosity observed is quite penetrative and affect all the lithologies. Narrow quartz veins are usually intersected. It is interpreted that NS sinsitral shears have caused reactivation of primary NE bedding parallel structures, resulting in dilation zones and subsequent gold mineralization at Kiaka. There is also no particular lithological control to the Kiaka mineralization style, however areas of highest lithological contrast present better host for gold mineralization.
There are four mineralised zones recognized at Kiaka. From NW to SE, these include KHZ, KIZ, KMZ and KFZ. The KMZ provides the largest target for resource ounces as it attains widths in excess of 200m in places and averages over 130m over the strike extent drilled to date.
Gold mineralization at Kiaka is low grade, associated with broad alteration system (silica-biotite-chlorite), and pyrrhotite (85%), fine pyrite (9%), and arsenopyrite (4%), with no real correlation between gold grade and percentage of sulphides. These sulphides can be disseminated or following the fabrics. Petrographic studies found gold mainly in inclusion in metamorphic minerals (hornblende, biotite, etc) suggesting that the gold mineralization event have been originally introduced either pre-metamorphic or during the early stages of the main metamorphic event with subsequent remobilization during a shearing event. It appears that the higher grade zones can be defined within the broad low grade halo and these can be correlated with retrograde metamorphic assemblages.
Previous Exploration
Randgold have already completed fairly extensive exploration programs at Kiaka since the identification of the target by regional lithosampling. This has involved detail geological and regolith mapping, soil geochem, pitting, trenching, drilling (RAB, RC, DDH), petrography studies, ground magnetics, rock density, as well some metallurgical test work and geological modelling.
Follow up detail soiled geochemical sampling at 50 X 200m spacing, oriented 120° and covering an area of 4 km x 2 km has been completed over the Kiaka prospect with a total of 820 samples collected and ssayed for Au and As. In addition, a ground magnetic survey was completed over the detail soil grid at the spacing of 5 X 200m over the same grid area. Results of the survey have highlighted the main NE and NS structures as well the variation of the dip of the NE structure. Regolith mapping over the detail soil grid has been completed. This involved rock and alteration description, structure measurement and lithosampling. A total of 675 lithosamples were collected.
A total of 6 regional prospects have been identified, of which only Kiaka has been drilled to any significant degree.
A total 11 trenches for a total 2,450m were excavated over the deposit, spaced at 100m to 200m, whilst 247 pits for a total aggregate depth of 931.5m, were excavated over 7 lines where regolith issues were complex. In addition a RAB drilling program was compeleted at Kiaka with 260 heel to toe holes for a total of 4,401m.
RC and Diamond drilling was undertaken to a spacing of mostly 100m between fences. This included: 11 RC holes for 1,125m, 24 diamond holes for 7,873.5m drilled in 4 phases almost covering the entire strike of 3km of gold mineralization defined in the hanging hole and the main zone.
Metallurgy and Petrography
Randgold submitted 78 samples from core and outcrops to study the alteration, mineralization, rocks type and their relationship to gold mineralization. From these samples, 12 sulphide samples of Kiaka ore have been submitted for systematic gold scans. Petrographic work suggested that the gold is generally located on grain boundaries and fractures and therefore ores are unlikely to be refractory. There were also no preg-robbing components identified.
The petrographic observations were supported by preliminary metallurgical test work where 194 samples were sent to Randgold's Loulo facility for CIL/bottle roll metallurgical testing. Recoveries obtained ranged between 80% and 98%, with the majority of samples returning better than 90%.
A 500kg of composite of fresh core samples was sent to SGS Johannesburg for column leach testing on a 6mm crush. This unoptimised test returned >60% recovery.
Current Exploration
Volta is currently drilling a >22,000m drilling program in order to produce a NI43-101 compliant resource that will facilitate fast tracking the project toward a development decision. The intention is to complete the central area (comprising the 750m strike extent modelled by Randgold) of the deposit to a 50m x 50m pattern down to a depth of 150m (possibly sufficient for Measured and Indicated Resources) and 100m x 50m down to a depth of 200m (possibly sufficient for Indicated or Inferred Resources). This drilling will also include covering the KHZ, KIZ and KFZ zones in the central area. It is also planned to extend this drilling at 50m x 50m spacing for 200m both north and south of the central area. In addition drilling will be undertaken on a 50m x 50m pattern down to 100m depth and 100m x 50m down to 150m depth in the southern area where Randgold defined some resources on the KHZ zone.
