MB Fluorspar, Nevada, USA
Defined Mineralisation & Optimised Pit

Defined Mineralisation & Optimised Pit

Drilling & 2015 Mineral Resource Estimate

Drilling & 2015 Mineral Resource Estimate

Phase 2 Drilling

Phase 2 Drilling

Phase 2 Drilling Samples

Phase 2 Drilling Samples

Trench on MB project

Trench on MB project

Historic Drill Plan

Historic Drill Plan

Drilling Cross Section A-A'

Drilling Cross Section A-A'

Drilling Cross Section B-B'

Drilling Cross Section B-B'

Drilling Cross Section C-C'

Drilling Cross Section C-C'

Project Location Plan

Project Location Plan

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MB Fluorspar, Nevada, USA

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The MB Project

On 3rd September 2012, as part of its strategy to build and develop a portfolio of long- life, high value fluorspar resources in stable, democratic and mining friendly jurisdictions, Tertiary Minerals plc announced a lease agreement and option to acquire a group of mining claims in Nevada (“the MB Property”), western USA.

Historic exploration results define a major fluorspar deposit that, the Company believes, could have world class potential.

The US Government considers fluorspar to be a strategic mineral. There is a large market for fluorspar in the US and around the Pacific Rim, but currently no significant US production.

Location

The MB Project claims are located 19km southwest of the town of Eureka in central Nevada. Eureka is on US Highway 50 and is the administrative centre for Eureka County which hosts a number of major mines including Barrick’s Ruby Hill Mine and other major deposits such as General Moly’s Mt. Hope porphyry molybdenum development.

Nevada is long recognised as one of the most attractive mining jurisdictions in the world and The MB Project now comprises 146 contiguous unpatented mining claims covering an area of approximately 2,800 acres.

Historic Exploration Results

The MB Property was first explored in the 1960s by Union Carbide for beryllium and subsequently for different commodities by a number of different companies including Asarco, Bear Creek Mining, U.S.Borax, Amselco, Arimetco and Homestake. A total of 108 drill holes were completed.

The Company has been able to source all of the drill results for these explorers, which although mainly exploring for other commodities, included fluorspar (fluorine) in their analyses. The drill results build a clear picture of the large scale of the mineralisation. The data includes a report by Asarco which refers to a tonnage-grade estimate of 110 million tonnes grading 10% CaF2. All of the Asarco drilling falls within the Property. Drilling carried out after Asarco included even deeper drilling by Bear Creek Mining which shows that fluorspar mineralisation was continuing at the end of holes nearly 400m deep.

All significant drill results are shown in the attached table. Significant drilling results extend over an area of 1.5km by 1.5km with drill intersections both from surface and at depths of up to 400m. Drill intersections in the range of 20-130m thick grading c.10% fluorspar are numerous and the majority of such holes ended in fluorspar mineralisation e.g.

Higher grade intersections are also reported e.g. 13.7m grading 21.3% CaF2 from 44.20m in Asarco hole A10 and 14.9m grading 20.6% CaF2 from 331 metres in Bear Creek hole BC11.

Geology & Style of Mineralisation

At the MB Project flat lying fluorspar mineralisation occurs as a skarn-type replacement of flat lying limestone beneath a quartzite cap. The source of the mineralising fluids in skarn systems is usually a granite intrusive and mineral grades tend to increase where fluid flows are focused or pooled – for example at impermeable barriers such the overlying quartzite. The style of mineralisation also tends to change with distance from the source intrusion and is often higher grade, sometimes with associated base or precious metal mineralisation, proximal to the source granite and lower grade in more distal zones. The source granite has not yet been intersected and so there is an exciting additional target for high grade mineralisation in proximal zones not yet tested by drilling.

11.9m grading 0.42% beryllium oxide in Bear Creek hole BC11 from 386.8m to base of hole,

and highly anomalous zinc and molybdenum e.g.:

10.5m grading 2.49% zinc from 157.86m in Bear Creek hole BC9 &  3.0m grading 0.56% molybdenum from 103.6m in Asarco holes A10.

Metallurgical Characteristics

A programme of metallurgical testwork was carried out in the 1960s by the US Bureau of Mines (now disbanded) on two samples of fluorite ore grading 27.1% and 10.5%CaF2. High grade concentrates grading 96-98% CaF2 were produced with recoveries from 85-94% at a coarse grind and with limited cleaning stages. This offers encouragement that an acid grade of fluorspar can be produced from the deposit.

Tonnage Grade Estimate

The Company has been unable to locate historic drill core or other drill samples from the MB Project. They may not have been preserved. Consequently the Company is not currently in a position to carry out any re-sampling of historic samples to generate comparative data that would allow the historical results to be used in a modern estimate of a code-compliant Mineral Resource.

However using the historic data the Company commissioned Wardell Armstrong International Ltd (WAI) to complete a Tonnage-Grade Estimate for the MB Project, classified as an Exploration Target under the JORC code (2004). The Tonnage-Grade range was estimated at 85-105 million tonnes grading 9-11% fluorspar (CaF2) at 8% cut-off grade. The Exploration Target is part of a larger mineralised system estimated at 395-615 million tonnes grading 5-7% fluorspar at 2% cut-off grade. WAI recommended a staged drilling programme in order to upgrade the Exploration Target to a JORC compliant Mineral Resource and to target potential higher grade areas of the deposit having limited historic drilling information.

Drilling Programme

The drilling programme was planned in May 2013 and the Drilling Permit was subsequently approved by the US Bureau of Land Management (BLM) in late June 2013. Phase 1 of the drilling was a 550 metre (4 holes) programme designed to test and compare results from core and reverse circulation percussion drilling techniques and to evaluate suitable analytical techniques for fluorine. Significant intersections of fluorspar (CaF2) were reported in phase 1 e.g. 42.67m grading 12.4% CaF2 from 4.57m in hole 13TMBRC001 including 4.57m grading 26.1% CaF2 from 6.10m depth and 12.19m grading 16.5% CaF2 from 25.91m depth.

 Phase 2 of the drilling programme was completed using the reverse circulation percussion method and was a 2,670 metre (22 holes) programme designed to define a JORC compliant Mineral Resource for a part of the deposit which would support planning of a mine-starter pit for up to the first ten years of production. Additionally some of the planned holes targeted potentially higher grade areas of the deposit. 

Maiden JORC Compliant Mineral Resource Estimate

In April 2014 the maiden JORC compliant Mineral Resource Estimate was completed by Wardell Armstrong International Limited (WAI) for the MB Fluorspar Project. Further details may be found in the RNS dated 16th April 2014

The Mineral Resource estimate and classification has been prepared in accordance with the Australian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves JORC Code (2012). Sample data was imported and verified before mineralised zones were defined to a cut-off grade of 2.0% CaF2. Samples were composited and subsequently used to produce a Mineral Resource Estimate of the CaF2 mineralisation at the MB project using inverse power distance as the principal estimation method.

The fundamental consideration to classify a Mineral Resource in accordance with guidelines of the JORC Code (2012) is that it has a “reasonable prospect for eventual economic extraction”. Mineral Resources are classified, in order of increasing geological confidence, into Inferred, Indicated and Measured categories.

WAI considers that the MB Project has been sufficiently explored to estimate Indicated and Inferred Mineral Resources as defined by JORC Code (2012).

WAI has classified the area of the southern part of the MB Project where the 2013 drilling has been completed roughly on an 80m x 80m grid and at least three north-south profile lines have been completed as Indicated Resources.  WAI has classified the remainder of the deposit as Inferred Resources where estimated blocks are within 120m of a 2013 drillhole.

The Mineral Resource is restricted to all material falling within an optimised pit shell created in CAE Mining NPV Scheduler and above a cut-off grade of 8% CaF2.  The base of the southern pit has a maximum depth of approximately 120m from current surface and the central area pit has a maximum depth of approximately 130m from current surface.

The Mineral Resource Estimate for the MB project is shown below. 

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Phase 3 Drilling & JORC Compliant Mineral Resource Upgrade

The Company moved quickly onto planning the next phase of drilling, Phase 3, following the completion of the maiden JORC 2012 Mineral Resource Estimate. The Phase 3 drilling programme completed in November 2014 and comprised a further 9 holes totalling 2,516 metres using the reverse circulation (percussion) method of drilling. The key objectives of the Phase 3 drilling programme were to:

The objectives of the Phase 3 drilling programme have been achieved resulting in a significant increase, more than doubling the size, of the 2014 Maiden JORC compliant Mineral Resource (RNS dated 17 June 2015). The 2015 JORC compliant Mineral Resource Estimate completed by Wardell Armstrong is shown below.

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Geophysical Programme and Phase 4 Drilling

Following the Phase 3 drilling and Mineral Resource Estimate upgrade the Company has completed a 166 line-km ground magnetic survey in order to gain an improved geological understanding of the fluorspar deposit potential structural controls and better understand the true potential of the deposit. Using the magnetic data together with the previous drilling results, the Company planned the next phase of drilling, Phase 4, with the key objective being to: 

Four holes were completed, totalling more than 1553m, using the reverse circulation drilling method.

Highlights of the Phase 4 drilling programme:

The Next Step

Following further evaluation of Phase 4 drilling results the priority for the Company is to move onto the next phases of development for the MB Project in 2016, including: