Montero Mining and Exploration Ltd

Montero Mining and Exploration Ltd

May 16, 2011 09:30 ET

Montero Drilling Returns 6.23% TREO Over 20.84 Metres, Including 11.51% TREO Over 4.51 Metres and 16.68% TREO Over 1.39 Metres at Wigu Hill

TORONTO, ONTARIO--(Marketwire - May 16, 2011) -


Montero Mining and Exploration Ltd. (TSX VENTURE:MON) has received initial assay results of diamond drill samples from its Wigu Hill REE project in Tanzania. Wigu Hill is a Light Rare Earth Element (LREE) project with the mineral bastnaesite being the dominant rare earth mineral.

A 2,150 metre diamond drill hole program was completed at the eastern end of Wigu Hill. Drill testing of the Twiga and Tembo zones was designed to test the continuity of the bastnaesite-rich carbonatite dykes down to a vertical depth of approximately 100 metres with a view to establishing a resource. A total of 19 drill holes were completed prior to suspending the drill program in April due to the onset of the rain season. The majority of the holes were inclined at 50° to cut the steeply dipping dykes, with only one hole being drilled vertically on a shallow dipping dyke. Results of the Tembo drilling (5 drill holes) are pending laboratory analysis while select results from 8 of the 14 drill holes completed at Twiga returned the following results:

Twiga Drill Target - Phase 1 Drilling
Bore Hole IdentificationFromToInterval (m)True Thickness (m)TREO %La2O3

Commenting on the results, Dr Tony Harwood, President of Montero said, "The high total rare earth oxide (TREO) values obtained over true widths are very encouraging and confirm the TREO values identified by the surface trenching. The Twiga EW bastnaesite-rich carbonatite dykes can be traced over a strike length of over 200m.The three drill sections have tested the inner 120 metres of this trend and confirmed the geological continuity of the dykes at depth together with significant mineralisation."

At the Twiga Drill target, Phase 1 drilling was undertaken to test the depth extent of the mineralised bastnaesite-rich carbonatite dykes identified by the initial surface exploration. The drill intersections confirm the continuity of the carbonatite dykes at depth and demonstrate the presence of bastnaesite mineralisation within medium to large centimetre scale crystals of burbankite in dolomitic carbonatite which is locally brecciated. The dip of the EW trending carbonatite at Twiga ranges from 35° to 47° in the trenches. In the drill holes the dip is found to range from 40° to 45° confirming the surface measurements.

Borehole BH TW003R returned the highest value from these drill results of 16.68% TREO over a sample width of 1.39 metres true width; the drill hole intersection grades at 6.23% TREO over a true width of 20.76 metres and this confirms at depth the high grade assay values returned from trench CT8b which grades 12.43% TREO over a true width of 5.70 metres (Press release April 11, 2011).

Good geological and grade continuity of the individual dykes is observed on the Twiga Target Section.

Click here to view:

Boreholes BH TW002, TW005 and TW006 provide good geological continuity along this section line. The near surface intersection of BH TW002 averages 5.58% TREO over a true width of 7.13 metres and BH TW005 delivers the equivalent intersection with grades at 5.73% over a true width of 8.48 metres. In the deeper borehole, TW006 the equivalent zone grades at 3.38% over 4.11 metres and 4.31% over 3.02 metres, all true widths. The same zone in Trench CC2 returns values of 13.28% TREO over 10.23 metres true width.

Borehole BH TW001 is drilled beneath Trench CC4. The borehole intersection grades at 6.09% TREO over a true width of 8.94 metres, with the trench values averaging 6.94% TREO over a true width of 6.48 metres.

Drilling has also been undertaken on the Twiga Drill Target - NS dykes and on the Tembo Drill Target dykes. The assaying of these drill hole samples is in progress.

Discussion on the analytical procedures:

Certified Standard: A certified standard was prepared by AMIS (African Mineral Standards) in Johannesburg, South Africa. This standard was used as reference material in the analysis of the samples reported here.

Analytical Laboratory: The samples presented here were analysed by ALS Chemex in Vancouver after sample preparation was undertaken at their facility in Mwanza, Tanzania. The AMIS certified standard was inserted as sealed packets at intervals of 20 samples. Analyses for high grade REE elements are performed by lithium meta-borate fusion and ICP-MS, an analytical package of 38 elements. Rock forming elements are analysed by lithium meta-borate fusion followed by dissolution of the melt and ICP-AES analysis. An option is available to analyse over limit REE's by ME-OGREE. For this batch of assays numerous samples were analysed for Ce, La and Pr to quantify the higher values of these elements.

Definition of TREO: The use of the term TREO (Total Rare Earth Oxides) in this release includes only the 15 defined rare earth oxides, namely:- Most abundant – Ce2O3, La2O3, Nd2O3, Pr2O3 and Sm2O3 (referred to as light rare earth oxides). These 5 Rare Earth Oxides make up over 99% of the rare earth element content, particularly for values >1% TREO. Others:- Eu2O3, ErO3, DyO3, Gd2O3, Ho2O3, HfO3, Tb2O3, Tm2O3, Lu2O3 and Yb2O3 (Pm was not assayed) are present in minor to trace amounts only. Values for elements such as Y or Nb, are not included and have not been reported here.

QA/QC: Montero has used blanks, field duplicates and one analytical standard to monitor the sampling and analytical quality. Results to date for the blank and field duplicates show acceptable quality for the main REEs of interest. The standard used was prepared on behalf of Montero using material from Wigu Hill and has certified analytical values for Ce, La, Pr and Sm based on analyses from 16 different laboratories. A review of the results reported by ALS Chemex and performed by AMEC indicates that these meet the required level of analytical quality. Chain of custody protocols require the signing and maintenance of logs and receipts each time the samples are picked up from or delivered to a new location. All shipping sacks are sealed with a numbered tag, the removal of which is recorded upon receipt by the laboratory.

Qualified Person's Statement

The technical information contained in this press release has been reviewed by Mr. Mike Evans, M.Sc. Pr.Sci.Nat., who is a qualified person for the purpose of National Instrument 43-101 and a consulting geologist to Montero.

About Montero Mining & Exploration

Montero Mining and Exploration Limited is a mineral exploration and development company focused on Rare Earth Element (REE), uranium and phosphate deposits in Tanzania, Canada and South Africa. Our Wigu Hill project in Tanzania is a large, REE enriched, undeveloped carbonatite vein system that the company is drilling in 2011.

Rare Earth Elements (a group of 15 metals) are critical in the advancement and development of emerging "green" technologies and high-tech applications such as electric and hybrid vehicles, wind and hydro power turbines, energy efficient lighting, LCD screens, MRI, x-ray machines and neodymium-based magnets crucial to ear-buds, MP3 Players, microphones, mobile devices and other computing equipment. Currently China produces 97% of world supply of REEs and these are becoming increasingly critical to both 21st Century technological progress and environmentally sustainable development.

Montero's growth strategy is to develop the Wigu Hill REE project and build a portfolio of REE projects through licence application, acquisition and exploration to bring these to account by eventual production and cash flow. Montero plans to operate in an environmentally and socially responsible manner while adding value to all stakeholders.

CAUTIONARY STATEMENT: This news release contains forward-looking information which is not comprised of historical facts. Forward-looking information involves risks, uncertainties and other factors that could cause actual events, results, performance, prospects and opportunities to differ materially from those expressed or implied by such forward-looking information. Forward looking information in this news release includes, but is not limited to, Montero's objectives, goals or future plans, and the estimated timing and cost of the exploration of the Wigu Hill Project. Factors that could cause actual results to differ materially from such forward-looking information include, but are not limited to, those risks set out in Montero's public documents filed on SEDAR. Although Montero believes that the assumptions and factors used in preparing the forward-looking information in this news release are reasonable, undue reliance should not be placed on such information, which only applies as of the date of this news release, and no assurance can be given that such events will occur in the disclosed time frames or at all. Montero disclaims any intention or obligation to update or revise any forward-looking information, whether as a result of new information, future events or otherwise, other than as required by law.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

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