9th Mar 2012 07:00
Nyota Minerals Limited ("Nyota" or the "Company")
Tulu Kapi Resource Update
Highlights
New Mineral Resource estimate for Tulu Kapi of 17.97 million tonnes @ 2.90g/t gold containing 1,672,000 ounces of gold;
o Comprises an upgrade and increase in the Indicated category of 82 per cent to 831,000 ounces of gold @ 3.01g/t gold; and
o An Inferred Resource of 841,000 ounces of gold @ 2.79g/t gold;
Resource estimation work completed by independent consultant Wardell Armstrong International ("WAI" or "Wardell Armstrong") in accordance with the guidelines of the JORC Code (2004);
A new drill programme is being designed specifically to convert Inferred ounces to Indicated ounces around the margin of the current Indicated Resource;
The resource upgrade and increase in Indicated Resource reflects the on-going development of a robust and detailed geological and structural model.
Mineral Resource Estimate
Nyota Minerals (ASX/AIM: NYO), the gold exploration and development Company in East Africa, is pleased to announce a Mineral Resource update for its Tulu Kapi Project, in Ethiopia.
The new resource benefits from significantly more geological detail than that previously available and incorporates all the drill holes for which gold analyses had been received up to and including the end of January 2012. Drilling completed since the start of January will form part of a subsequent resource estimate update mid-year.
Richard Chase, Chief Executive Officer commented, "I am pleased to announce an updated JORC resource at Tulu Kapi. The resource drilling completed between June and the end of December last year focused on increasing confidence in the geological model so as to convert Inferred Resources to Indicated Resources, as well as increasing the overall contained gold without a significant change in tenor. Both of these objectives have been achieved.
"While drilling is currently focused on engineering and hydrogeology for the Definitive Feasibility Study, our geology department and Wardell Armstrong are designing a new drill program to target the conversion of a large part of the Inferred Resource that surrounds the current Indicated Resource that is at the heart of the conceptual open pit. Drilling of this programme is expected to commence in the second quarter of the year."
Mineral Resource Update & Geological Model
The resource estimation was undertaken using Ordinary Kriging interpolation and employs the same cut-off grades as were used in the Mineral Resource estimate of June 2011.
Tulu Kapi Resource Estimate - In-Situ Model (WAI, March 2012) (Prepared in accordance with the guidelines of the JORC Code (2004) | |||||
Mineralisation Type | Saprolite | Fresh | Total | ||
Cut Off Grade (g/t) | 0.4 | 0.5 | 0.4 / 0.5 | ||
Indicated | Tonnage (kt) | 425 | 8,157 | 8,583 | |
Au (g/t) | 1.87 | 3.07 | 3.01 | ||
Metal | kg | 796 | 25,056 | 25,852 | |
k.oz | 26 | 806 | 831 | ||
Inferred | Tonnage (kt) | 395 | 8,989 | 9,385 | |
Au (g/t) | 1.57 | 2.84 | 2.79 | ||
Metal | kg | 622 | 25,534 | 26,157 | |
k.oz | 20 | 821 | 841 | ||
NB - 1. Mineral Resources are not reserves until they have demonstrated economic viability based on a feasibility study or pre-feasibility study. 2. Mineral Resources are reported inclusive of any reserves. 3. Grade represents estimated contained metal in the ground and has not been adjusted for metallurgical recovery. |
Note: Nyota holds an interest of 100% in the Tulu Kapi asset
The Company has previously noted that the Tulu Kapi deposit is bounded by a series of faults with various orientations dominated by the Bedele Shear, which defines the eastern and southern boundaries of the known deposit.
Recent drilling has focused on these individual faults, with the result that it has been possible to model these structures in more detail and in the process establish unique fault bound blocks of mineralisation which have been individually modelled by WAI. The mineralisation within individual fault bound blocks shows subtle variations in dip and strike of the mineralised structures. These can now be identified and modelled, overcoming previous difficulties in demonstrating continuity between fault boundaries.
With the containment of mineralisation within fault blocks it is possible to clearly demonstrate continuity which is reflected in the significant increase in the Indicated Resource by approximately 82 per cent to 831,000 ounces of gold; as set out in the table below. The new geological model also reflects the major input from the Company's exploration team based at Tulu Kapi.
Tulu Kapi Resource Estimate - In-Situ Model (WAI, March 2012 compared with WAI, June 2011) (Prepared in accordance with the guidelines of the JORC Code (2004) | |||||||||
June 2011 | March 2012 | Difference | |||||||
Mineralisation Type | Saprolite | Fresh | Total | Saprolite | Fresh | Total | |||
Cut Off Grade (g/t) | 0.4 | 0.5 | 0.4 / 0.5 | 0.4 | 0.5 | 0.4 / 0.5 | |||
Indicated | Tonnage (kt) | 277 | 4,394 | 4,671 | 425 | 8,157 | 8,583 | +83% | |
Au (g/t) | 2.42 | 3.08 | 3.04 | 1.87 | 3.07 | 3.01 | -1% | ||
Metal | kg | 670 | 13,531 | 14,200 | 796 | 25,056 | 25,852 | +82% | |
k.oz | 22 | 435 | 457 | 26 | 806 | 831 | +82% | ||
Inferred | Tonnage (kt) | 811 | 10,481 | 11,291 | 395 | 8,989 | 9,385 | -18% | |
Au (g/t) | 2.02 | 2.82 | 2.76 | 1.57 | 2.84 | 2.79 | +1% | ||
Metal | kg | 1,636 | 29,548 | 31,184 | 622 | 25,534 | 26,157 | -16% | |
k.oz | 53 | 950 | 1,003 | 20 | 821 | 841 | -16% |
Finally, and in keeping with previous resource estimate announcements, the table below shows how the In-Situ Mineral Resource Estimate model ("In-Situ") changes when a geometrical mine plan comprising of 2.5m high benches is imposed upon it ("2.5m Bench Dilution"). The purpose to this exercise if to gain a better understanding of the likely tonnes and grade that will be treated by the process plant, as opposed to the tonnes and grade that is present "in-situ" in the ground.
The gold in the upper parts of the Tulu Kapi ore body is contained predominantly in sub-horizontal and shallow dipping lenses in zones of alteration. Therefore, the effect of using regularly sized rectangular blocks to model it as one would mine it (and when all other factors are left unchanged) is to force the inclusion of low grade material and internal waste that must be removed along with the ore. As a result, the gold metal contained in the resource estimate remains almost unchanged but the number of tonnes increases and the average grade of those tonnes decreases.
Tulu Kapi Resource Estimate In-Situ Model V's 2.5m Bench Dilution Model (WAI, March 2012) (Prepared in accordance with the guidelines of the JORC Code (2004) | ||||
Model | In-Situ | 2.5m Bench Dilution | ||
Cut Off Grade (g/t) | 0.4 / 0.5 | 0.4 / 0.5 | ||
Indicated | Tonnage (kt) | 8,583 | 13,114 | |
Au (g/t) | 3.01 | 1.88 | ||
Metal | kg | 25,852 | 24,644 | |
k.oz | 831 | 792 | ||
Inferred | Tonnage (kt) | 9,385 | 13,176 | |
Au (g/t) | 2.79 | 1.83 | ||
Metal | kg | 26,157 | 24,079 | |
k.oz | 841 | 774 |
A major part of the Definitive Feasibility Study is to conduct detailed trade-off studies based upon the costs estimated by the study to establish the most appropriate cut-off grade, mine plan and process plant design to maximize the value of the ore body. The above illustration is therefore for guidance only when considering the possible cash flow from Tulu Kapi; the base case assumption remains that the process plant will treat 2 million tonnes of ore per annum with a gold recovery of +94%.
Further Resource Potential
Opportunities remain for the delineation of additional resources immediately adjacent and proximal to the Tulu Kapi deposit including the North and NE Extensions, UNDP and SW Extension. These targets are defined by a combination of airborne and ground geophysics, soil geochemical survey, trenching and initial drilling.
In addition to these new target areas, the Company now also has sufficient information to be able to focus on areas of the deposit that are currently defined as Inferred Resources, but where an upgrade and conversion to an Indicated status could be both straight forward and reasonably swift based on recent successes. As such, an upgrade programme will commence as soon as engineering and hydrogeological drilling (forming part of the Definitive Feasibility Study) is complete and a reverse circulation rig becomes available.
Competent Persons
The Resource Statement is the responsibility of Principal Geologist Che Osmond BSc MSc MCSM CGeol FGS EurGeol. Che Osmond is a full‐time employee of Wardell Armstrong International, an independent Consultancy and has sufficient experience which is relevant to the style of mineralization and type of deposit under consideration, and to the type of activity which he is undertaking to qualify as a Competent Person as defined in the June 2009 Edition of the AIM Note for Mining and Oil & Gas Companies. Che Osmond consents to the inclusion in the announcement of the matters based on their information in the form and context in which it appears and confirms that this information is accurate and not false or misleading.
For further information please visit: http://www.nyotaminerals.com or enquire to:
Richard Chase (CEO)
Nyota Minerals Limited
+44 (0) 20 7400 5740
info@nyotaminerals.com
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Glossary of Technical Terms
"cut‐off" | the lowest grade value that is included in a resource statement. It must comply with JORC requirement 19: "reasonable prospects for eventual economic extraction" the lowest grade, or quality, of mineralised material that qualifies as economically mineable and available in a given deposit. It may be defined on the basis of economic evaluation, or on physical or chemical attributes that define an acceptable product specification. |
"g/t" | grammes per tonne; equivalent to parts per million ('ppm'). |
"Inferred Resource" | that part of a Mineral Resource for which tonnage, grade and mineral content can be estimated with a low level of confidence.
It is inferred from geological evidence and assumed but not verified geological and/or grade continuity. It is based on information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes which may be limited or of uncertain quality and reliability. |
"Indicated Resource" | that part of a Mineral Resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a reasonable level of confidence. It is based on exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. The locations are too widely or inappropriately spaced to confirm geological and/or grade continuity but are spaced closely enough for continuity to be assumed. |
"In‐situ" | when used as a prefix to "mineral resource" serves to emphasise that the resource estimate is of the mineralisation as it occurs "in-situ" and, other than the use of a cut‐off grade, does not include any other economic considerations or factors for dilution caused by mining. |
"JORC" | the Australasian Joint Ore Reserves Committee Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, 2004 (the "JORC Code" or "the Code"). The Code sets out minimum standards, recommendations and guidelines for Public Reporting in Australasia of Exploration Results, Mineral Resources and Ore Reserves |
"Kriging" | an interpolation method for assigning values from samples to ore blocks that minimizes the estimation error. |
"Measured Resource" | a measured Mineral Resource is that part of a Mineral Resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a high level of confidence. It is based on detailed and reliable exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. The locations are spaced closely enough to confirm geological and grade continuity. |
"Mineral Resource" | a concentration or occurrence of material of intrinsic economic interest in or on the Earth's crust in such form, quality and quantity that there are reasonable prospects for eventual economic extraction. The location, quantity, grade, geological characteristics and continuity of a Mineral Resource are known, estimated or interpreted from specific geological evidence and knowledge. Mineral Resources are sub‐divided, in order of increasing geological confidence, into Inferred, Indicated and Measured categories when reporting under JORC. |
"oz" | troy ounce (= 31.1035 grammes). |
"saprolite" | a weathered rock. Saprolites form in the lower zones of soil profiles and represent deep weathering of the bedrock. |
"t" | tonne (= 1 million grammes). |
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