Wigu Hill, Tanzania

The Wigu Hill Rare Earth Element ("REE") Project is a light rare earth element deposit and a large carbonite complex with bastnaesite mineralization. The licence area covers 142km2. Initial grab samples yeilded results as high as 27.25% TREO. Montero released an initial NI 43-101 Inferred resource estimate of 3.3Mt at 2.6% LREO5 including 510K @ 4.4% LREO5 on 2 of 10 possible drill targets. Further exploration drilling to add to the current resource is underway. Click the title to download and view the NI-43-101 Report

Montero revised a portion of its initial NI 43-101 compliant Inferred Mineral Resource estimate of 3.3M tonnes at 2.6% LREO5 (Light Rare Earth Oxides) for the Tembo and Twiga Zones. The updated resource estimate is only for the Twiga Zone and is based on data from the initial 15 core boreholes (1,560m) used in the initial resource estimate and data from infill drilling of 17 boreholes at 25m intervals (986m) completed in 2012. The data used in the revised Twiga Zone overall resource has outlined a higher grade REE deposit for this zone on the south-eastern ridge of the Wigu Hill carbonatite complex. A total Inferred Mineral Resource of 1.9 million tonnes at a grade of 2.7% LREO5 has been estimated from the preliminary and infill drilling of 32 boreholes (2,546m) for the Twiga Zone to a depth of 50m. A sensitivity analysis at a cut-off grade of 3% LREO5 has shown that the Inferred Mineral Resource contains a higher-grade portion consisting of 0.47 million tonnes averaging 5.2% LREO5. The independent estimate was prepared by AMEC Earth & Environmental Services (UK) Limited (AMEC). See full news release by clicking here


The Wigu Hill Property is located in Tanzania, 170 km south-west of Dar es Salaam, and 68 km south of Morogoro, the nearest major regional centre (straight line distances). The project area can be accessed by the all-weather Dar es Salaam-Marogoro road and it is 7 km from the TAZARA railway line with the nearest siding at Kisaki just 12 km away.


The carbonatite complex has been know since the 1950s and sampled many times by various mining and scientific organisations. A summary is listed below:

  • Early 1950 discovery of the deposit by the geological survey
  • 1957 New Consolidated Goldfields examined the hill for rare earth
  • 1973 - The area was explored by Molycorp Minerals
  • 1987 Tanzanian-Canadian Agrogeology project examined the area for phosphate potential
  • 2000 The area was examined by P.R. Siegfriend
  • 2007 BGR assessed the project on behalf of the Tanzanian government
  • 2008 Montero entered into an agreement with RSR in 2007
  • 2009 - Reconnaisance sampling and mapping of the Wigu Hill complex commenced
  • 2011 - Montero listed on the TSX.V in February and exploration commenced


The Wigu Hill Property is a large, REE enriched carbonatite with dolomitic vein system which cut into Precambrian gneisses. The deposit type would be best described as a high level, carbonatite hosted REE dike deposit. The principally coarse-grained carbonatite dikes largely contain dolomite, bastnaesite and quartz.

Mineralization is mainly concentrated in the carbonatite dykes although the surrounding country rocks appear to have low grade REE mineralization of unknown extent and grade. The REEs occur predominantly in the minerals bastnaesite, monazite and synchysite, although others such as parasite and goyazite have also been encountered. The carbonatite dykes that host the REE are typically 0.6-8.0m wide and can be traced intermittently over distances of over 700m. The deposit is a LREE dominated which is characteristic of most carbonatites. Sampling to date has revealed grades averaging over 7% total rare earth oxide (TREO), with individual samples up to 26.2% TREO.


Montero has embarked on a detailed mapping, trenching and drilling program on the prospect to better define the setting, distribution and nature of the mineralization. This has led to the delineation of 10 target areas; some of which advanced exploration work has been completed and is underway; Twiga, Tembo, Tumbili and Nyati


  • Surface dimensions of 500m by 150m
  • The area was drilled, trenched and grab samples taken
  • 14 diamond drill holes were drilled for 1465 m
  • The in-fill drilling program of 17 core boreholes (900 metres), drilled at approximately 25 metre spacings and down to an average inclined depth of 35 metres
  • Significant Results include: Trench CC2 10.23m @ 13.28% TREO including 3.65m @ 18.18% TREO and 0.73m @ 27.25 TREO and Drillhole TW003R: 20,76m @6.23% TREO including 4.03m@ 11.91%TREO and 1.39m@ 16.68% TREO


  • Surface dimensions of 500m by 150m
  • The area was grab, trench and drill sampled
  • 5 diamond drill holes were drilled for 540 m
  • Significant Results include: Trench 7: 1.75m@ 4.92% TREO including 6.45m@ 9.27% TREO and 2.00m @ 15.48% TREO and Drillhole TE001: 6.95m @ 3.59% TREO including 5.66% TREO


  • Surface dimensions of 1200m by 500 m
  • The area was drilled, trenched and grab samples taken
  • 6 core drill holes were drilled for 1,525m
  • Significant Results include: Trench 1: 18.0m @ 3.02% TREO with a maximum value of 2.3m @ 9.44% TREO and Drillhole TUM0002: 80.0m @ 1.04% TREO and TUM0002: 253.8m @ 0.61% TREO


  • Surface dimensions of 800m by 400 m
  • The area was mapped and grab samples taken
  • A much larger mineralized target area at Nyati (800m x1000m) outlined and subsequently divided into Upper and Lower Nyati
  • Significant Results include: Sampling from the NE Section: 2.51% TREO to 18.21% TREO with the average value from 55 samples returning 10.43% TREO and from the SW Section: 1.95% TREO and 13.03% TREO with an average value from 45 samples returning 5.85% TREO. Drilling highlights include: BH NYT001: 111.5m - 174m 62.5m @ 3.01% TREO and BH NYT005: 31.8m - 105m 73.2m @ 3.13% TREO (Including 4.92% over 24.30m)


  • Surface dimensions of 300m by 100 m
  • The area has been mapped and remains a future target of exploration

The Wigu Hill Rare Earth Project does not contain a mineral reserve and is not currently in production. Any decision to place the Wigu Hill Rare Earth Project into production requires the support of a feasibility study prepared in accordance with National Instrument 43-101. At this time the Company has completed a series of laboratory and pilot scale testwork, but this does not satisfy the requirements of a feasibility study. Accordingly, any decision to commence production on the Wigu Hill Rare Earth Project is neither imminent nor assured, and investors cannot assume that the Wigu Hill Rare Earth Project hosts an economic mine at this time.