Skip to main content

Migori Gold Project

  • RRR: 100% Economic Interest
  • RRR: 75% Project Interest
  • 1.2Moz gold JORC Resource
  • Kenyan Greenstone Belt
  • Exploring Partnership Opportunities

Kenya Kenya

Red Rock is exploring the Migori gold belt in Kenya. The under-explored Migori gold belt is analogous to producing Tanzanian greenstone gold belts and has significant upside potential.

Investment

Red Rock holds a 75% direct interest in Mid Migori Mining Company Ltd (“MMM”) which controls a 1.2Moz JORC gold resource in Kenya held in two exploration licenses.

Location

The licences (“SPL”), which cover an area of approximately 245km² are located in the SW corner of Kenya, approximately 290km west of the capital Nairobi. The project tenements lie within the Migori and Narok Counties, extending approximately 63km from Lake Victoria in the west and parallel to the Kenya/Tanzania border which lies 10km to the south. Barrick's North Mara gold operations are located 30km SE in Tanzania.  In February 2017 Barrick announced it had found "one of the highest grade gold projects in Africa today" in reporting its 1.31m oz Resource at 12.1grams per tonne (now 3.3m oz).

Geology

The Migori Greenstone belt (MGB) forms part of the Nyanzian supergroup, itself part of the northern extension of the gold-enriched Archaean Tanzanian craton. The granite-greenstone terrain to the south of the MGB is host to world class producing gold mines (e.g. North Mara 4Moz Au, Geita 7Moz Au).

The Tanzanian craton is of a similar age to other significant orogenic gold belts such as the Yilgarn in Australia and the Lake Superior province in Canada.  The mineralisation and stratigraphy of the MGB is similar to that of the Lake Victoria Greenstone belts in Tanzania and other Archaean greenstone deposits such as Red Lake in Canada (3.2Moz Au).

Gold enrichment within the MGB is predominantly found in and around shear zones associated with quartz-carbonate veining and significant alteration, as well as banded iron formations (BIFs) and poly-metallic Volcanogenic Massive Sulphides (VMS). The dominant lithologies are felsic and mafic intrusive, BIFs and metasediments of the Nyanzian system, overlain by younger Kavirondian volcaniclastic sediments and intruded by younger granitic intrusions.

The Migori Project possesses approximately 245km² of prospective greenstone geology, extending 63km along strike. The belt has a rich history of colonial and artisanal mining.

Exploration History

Exploration in the project area began in the early 1930’s and culminated in the identification and subsequent mining of the Macalder VMS. In addition to this, several historical operators identified lode gold prospects which lead to the first MRE publication in 2006.

In 2010, Red Rock began the extensive task of GIS file organisation, data digestion and compilation of available historic data, prior to commencing detailed field-based exploration including substantial drilling programmes.

Projects

Mikei Resource

The Mikei Resource totals 1.2Moz at JORC Indicated and Inferred status over five areas within the Mikei Shear zone.

Summary of CSA Reported Mineral Resource Estimate Statement (JORC-compliant @ 0.5 g/t Au cut-off)

Inferred Indicated Total
mt g/t Au mt g/t Au mt g/t Au Metal MOz
KKM  1.4  1.15  16.3  1.00  17.8  1.01  0.58
KKM-West  3.0  1.02  1.1  1.07  4.2  1.04  0.14
Nyanza  1.2  1.70  1.2  3.73  2.3  2.72  0.20
Gori Maria  3.8  1.16  0  0  3.8  1.16  0.14
MK  0.6  1.76  0.8  4.05  1.4  3.07  0.13
Total  10.0  1.21   19.4  1.29  29.4  1.26  1.19

NB. Apparent errors may occur due to rounding

Preliminary pit optimisations targeting areas of shallow, high grade mineralisation to determine the potential for economic development and ongoing resource expansion have been completed. Nyanza and Mikei prospects showed the best potential as starter pits due to lower metal price sensitivity and favourable conversion from Mineral Resources to diluted pit shell metal inventories.

In 2014, Red Rock commissioned a preliminary technical and economic assessment constituting the first stage of a feasibility study, confirming viability of the 200koz Au deposit as a standalone open pit operation for generating short term cash flow utilising a modular gravity plant.

Pit shells per year mined at one of the Migori key prospects

Migori Regional Exploration

Regional exploration remains a key component of Red Rock’s activities in Kenya with the objective of identifying new potentially economic targets and expanding the existing resource base.

Geophysics, traversing and geological mapping, grab sampling, trenching, aircore drilling and scout diamond drilling have been applied with success across large parts of the Migori licences, encountering intersections up to 12.9m @ 3.72g/t Au and generating 12 new regional exploration targets for further investigation.

Macalder Tailings Resource

The Macalder VMS deposit was discovered in the mid-1930s and mined for copper and gold till mid-1970s. The tailings produced during that period have been demonstrated by Red Rock to contain potentially economic levels of residual gold mineralisation amenable to cyanide leach extraction. A JORC Measured Mineral Resource Estimate has since been completed.

JORC Measured Resource Estimate

Prospect JORC Classification mt kOz Au g/t Au Cut-off g//Au
Macalder Tailings Measured 1.3 68 1.65 No cut-off

A scoping study investigated two base case scenarios (new vs used plant equipment) alongside a DCF analysis, examination of previous metallurgical test work and assessment of community and environmental factors. Mining Lease Application for processing the tailings has since been submitted to the Kenyan Government.

Looking forward

New prospecting licences have recently been granted for a period of three years, PL/2018/0202 and PL/2018/0203. The Company will now continue the work it began at the licences during the period to 2013. The work culminated with an initial 1.3 MMoz mineral resource under the JORC Code for the licences in 2012. It also found that gold recoveries of more than 90pc were achievable at a prospect called MK, while mineralisation at all prospects remains potentially open at depth and along strike of key higher-grade zones.

The next stage will focus on drilling and will involve more work on the higher-grade areas and on expanding the resource. The next stages of exploration will aim to increase the size of the resource and its grade.

Red Rock will pursue the early development of the tailings.

Highlights

  • JORC Mineral Resource Estimates:
    • Mikei Shear Zone - 1.2Moz Au @ 1.3g/t
    • Macalder Tailings - 68koz Au @ 1.7g/t
    • Significant resource expansion potential
  • Key Technical and Economic studies completed for the Nyanza hard rock and Macalder tailings gold deposits
  • Ongoing interpretation and desktop analysis of historic and recent results and planning for future exploration
    • The 7km long Mikei shear has upside potential between known zones
    • Significant resource expansion potential for both gold and base metals
    • 12 new regional targets identified and 15 existing targets have been re-prioritized