West Kenya Project
Shanta acquired the West Kenya Project in late 2020, believed to be among the highest grading gold projects in Africa, and a high-quality addition to the asset portfolio. At the time of the acquisition, the project had a high-grade NI 43-101 compliant inferred resources of 1,182,000 ounces grading 12.6 g/t at the Isulu/Bushiangala deposits. Other benefits of the acquisition for the Shanta Gold Shareholders include: A major presence in a geologically rich and underexplored greenstone gold region; Expands Shanta’s operating presence in East Africa with a diversified portfolio of exceptional assets delivering long term growth; An established Centre of Excellence at the New Luika Gold Mine will advance the West Kenya Project and complement the project team based in Kisumu, Kenya; Increases Shanta’s high-quality gold resource inventory to over 3 Moz contained gold with the prospect of future growth; and Complementary language and legal systems between Tanzania and Kenya based on English law.
The West Kenya Project covers approximately 1,162 km2 of the highly prospective Lake Victoria greenstone gold field in western Kenya. Presently, two potential mining centers have been identified on the West Kenya Project Shanta Gold Licences:
- Liranda Potential Mining Centre (Isulu-Bushiangala is the main resource-stage target) and
- Ramula Potential Mining Centre (Ramula is a new resource-stage target)
Other highlight targets include:
- Kimingini is an advanced-stage target potential to deliver a resource in proximity to Isulu-Bushiangala.
- Rosterman-Kakamega is an early-stage, poorly tested target in immediate proximity to the historic colonial mine, which had produced 0.25Moz @ 12.5g/t Au.
- Masumbi-Barding is also an early-stage target potential for a discovery of the low-grade bulk deposit.
- Dhene is a new target that has the potential for a discovery of a reasonably sized deposit in proximity to Ramula.
Post-acquisition, Shanta has undertaken various key processes to enhance the value accretion of this portfolio and to accelerate a construction decision for a third mine. Some of the more noticeable processes undertaken include:
- Commenced an independent Scoping Study for the high-grade West Kenya Project (Isulu/Bushiangala deposits), which was finalised in October 2020 and highlights include: Life of Mine (“LOM”) gold production of 949 Koz; Average annual gold production of 105 Koz for 9 years; Average head grade mined at 9.3 g/t; Open pit mining for 2 years followed by underground mining; and Conventional CIL processing plant with an annual processing capacity of 480 kt.
- Appointed Yuri Dobrotin, P.Geo as Group Exploration Manager effective 1 January 2021.
- Embarked on an infill drilling programme at the Isulu and Bushiangala deposits aimed at upgrading ounces from the Project’s NI43-101 compliant Inferred Mineral Resource Estimate into the Indicated Resource category down to a depth of 600 metres, across three drilling phases.
- In September 2021, Shanta announced a Resource update for the Isulu and Bushiangala deposits with highlights being 118 Koz grading 7.04 g/t converted to Indicated in total at a conversion rate of over 100%, following Phase 1 drilling.
- Continuation of other exploratory works and prioritisation of targets across the full portfolio in West Kenya.
- A total of 31,484 metres (“m”) were drilled at West Kenya in 2021 - including 3,704 m across district targets - costing US$4.8 million of direct drilling expenditure.
- In March 2022, Shanta announced a maiden resource estimate for the Ramula target of 434 Koz grading of 2.08 g/t and increasing total resources at our West Kenya Project by a significant 37% to 1.6 million oz.
During 2022, the West Kenya exploration team has the following key priorities:
- Maiden resource estimate for the Ramula target.
- Finalise the Phase 2 infill drilling programme and provide an updated mineral resource estimate at Isulu-Bushiangala as well as the re-estimated historical maiden resource at the Bumbo polymetallic target.
- Commence the Phase 3 infill drilling programme.
- Commence other feasibility related studies.
The Tanzania Craton forms the south-eastern extent of the Archaean Eastern Congo Craton, a 2,000 km long corridor, which extends from Tanzania in the south, northwest into the Central African Republic. The southern part of the Tanzania Craton is dominated by felsic Dodoma gneisses and granitoid rocks and local supracrustal Dodoma schist relicts (Kabete et al., 2012a). The northern part of the craton is composed of a Neoarchean granite-greenstone terrane of the Lake Victorian Goldfields (LVG), which provides the host environment for the gold deposits. The LVG comprises seven greenstone belts, Iramba/Sekenke, Nzega, Sukumaland, Kilimafedha, Musoma-Mara, Migori and Busia-Kakamega. Early workers recognised unifying stratigraphic themes within these greenstone belts.
The Busia-Kakamega Greenstone Belt lies on the northern edge of Lake Victoria extending northwest from Kakamega in Kenya, into Uganda. The belt comprises an overall northeast facing sequence of volcanic and sedimentary rocks intruded by granitoids. The oldest rocks are pre-2750 Ma Samia Hills Group in the west through the 2700- 2670 Ma Ndori group and 2670-2660 Ma Yala group, eastward into the 2660 Ma Kavirondo group (Sharp et al. 2016). The volcanic units, and their intrusive equivalents, include rocks of komatiitic, tholeiitic, calcalkaline and high potassium adakitic composition: the adakitic rocks within the Yala River group are intercalated with sandstone and conglomerate which has been included in the Kavirondo group in the past. The komatiitic suite hosted by the Ndori Group includes high-Mg basalts and ultramafic volcaniclastic rocks. The granitoids can be separated into two groups: an older calcic syn-volcanic suite predating deposition of the Kavirondo group sedimentary rocks and a younger circa 2650 Ma high potassium suite which post-dates the Kavirondo group. Most of the rocks throughout the Busia-Kakamega Greenstone Belt show remarkably little strain at the outcrop scale. Exceptions are occurrences of mafic volcanic meta-tectonites. Field relations suggest these meta-tectonites are passively intruded by the circa 2670 Ma Assembo granitoid, which provides a minimum age for this early deformation. Rocks of the younger Kavirondo group are locally folded and in places cut by a steep cleavage in outcrops. The inferred circa 2660 Ma age of the Kavirondo group provides a maximum age for this younger cleavage and a clear indication that there are at least two distinctive generations of structures in the belt. East-northeast faults are inferred across the belt from several lines of evidence. These faults are discordant features, most likely representative of younger deformation. The major structural grain of rocks in the central part of the belt is northeast, truncated by the north striking intrusive contacts of the circa 2655 Ma Maragoli and Mumias external batholiths.
Within the Busia Kakamega Belt two informal geological regions have been recognised, the Kakamega Dome in the northeast, a broad synclinal structure of volcano-sedimentary rocks and the Lake Zone in the southwest a northeast trending folded and thrusted volcano-sedimentary sequence.
Shanta currently has compliant resources at four separate deposits - Isulu, Bushiangala, Ramula, and Bumbo, confirming the widespread geological prospectivity of the West Kenya project.
Isulu and Bushiangala Deposits
Gold mineralisation at the Isulu and Bushiangala deposits is hosted by sheared pillowed to massive basalts, bounded between ultramafic volcanics and polymictic conglomerates on one side and carbonaceous mudstones and sandstones on the other side. The deposits occur within the Liranda Corridor area, a 12 km structural trend located on the eastern limb of a broad synclinal structure intruded in the center by granitoids and diorites, termed the Kakamega Dome. Mineralisation is associated with quartz and quartz-carbonate veinlets ranging from 0.5 m to 10 m in true width, which lies within the mineralised shear zones. The mineralisation style is classified as orogenic, shear-zone-hosted quartz-carbonate vein subtype.
The Bumbo polymetallic VMS deposit (Zn, Cu, Pb, Au, Ag) is situated 20km to the east of Isulu-Bushiangala. The mineralisation comprises lensoidal pyrrhotite-sphalerite-chalcopyrite massive sulphide and is characterised by a central core of massive sulphides with immediately adjacent more disseminated and inter-layered sulphides. The mineralisation is broadly conformable with the host metamorphosed sedimentary lithologies and has been interpreted as a volcanogenic massive sulphide (VMS) style of mineralisation with an orogenic Au overprint. The deposit is subdivided into two main lenses, each striking approximately east-west, and dipping steeply to the north. The strike extent of the mineralised system is over 500m.
The Ramula deposit lies primarily within a small dioritoid stock and its contact zones with the volcanics and is located approximately 35 km from the Liranda Region which contains the high grade Isulu and Bushiangala deposits. The stock has intruded a sequence of intermediate volcanic rocks (breccias, tuffs and lavas). Minor quartz-feldspar porphyry intrusives are present. The elongated dioritoid body is approximately 200m by 400m with a northwest-southeast trending long axis. Mineralisation mostly occurs within shallow south-west dipping stacked quartz veins hosted in the dioritoid body. However narrow zones of steep mineralised quartz veins also occur within the intermediate volcanics close to the dioritoid body. This area contains bulk mining potential.
The diorite exhibits pervasive hematite and chlorite/sericite alteration, while the volcanics are pervasively chlorite and epidote altered with common sericite and hematite. Mineralized zones are characterized by elevated amounts of pyrite. The main visual alteration assemblages are phyllic, propylitic, carbonatisation, hematisation and partial silicification. A south northwest- north southeast trending moderate foliation is observed in several outcrops only within the intermediate volcanics. A major interpreted thrust fault is located just north of the prospect.
The Ramula Region currently holds 7 high priority targets including Ramula, Miruka, Anomaly 22, Ramba-Lumba, Aila, Masumbi, and the former colonial mine Kiboko, all within 1-20 km of the Ramula deposit.