Perseus Mining Limited - RESOURCE-RESERVE UPGRADE - Ghana Gold Projects
/NOT FOR DISTRIBUTION TO UNITED STATES NEWSWIRE SERVICES OR FOR DISSEMINATION IN THE UNITED STATES/
PERTH, Western Australia, Dec. 23 /CNW/ - Perseus Mining Limited (ASX/TSX: PRU) ("Perseus") is pleased to release updated resource estimates for the Central Ashanti Gold Project ("CAGP") and the Grumesa Gold Project, in Ghana and a reserve upgrade for the CAGP.
Highlights
- 1.4Moz (42%) increase in Measured and Indicated ("M&I") mineral resources in Ghana.
- Total M&I mineral resources at CAGP now 118Mt containing 4.3Moz of gold (38% increase) including reserves of 87Mt containing 3.3Moz of gold (1.2Moz or 54% increase)
- Total M&I mineral resources for all projects now totals 159Mt containing 5.7Moz of gold
- Total reserves for all projects now totals 97Mt containing 3.9Moz of gold
- Total Inferred mineral resources for all projects now 73Mt containing 2.2Moz of gold
- Only one new deposit at CAGP bought into reserve, additional Resource and Reserve upgrades scheduled for 2011 will incorporate results from current drilling programs on multiple deposits
Mark Calderwood, Managing Director's Comments
"Most of the increase in overall mineral resources at the CAGP is attributable to extensions at depth and along or across strike at Abnabna-Fobinso and Esuajah South. Importantly, conversion of Inferred mineral resources to Measured and Indicated status from infill drilling remains high at approximately 100%. This is a positive reflection of the overall predictability of these gold deposits."
"The 1.2Moz added to ore reserves at Abnabna-Fobinso and Esuajah South this year is unlikely to be the last upgrade for these deposits as the Company continues to drill and evaluate both deeper open pit and bulk underground mining options."
"The planned 2011 round of resource and reserve upgrades will be focussed on a number of other deposits drilled over the past 12 months. Drilling of these deposits is continuing, with nine rigs currently working on the CAGP."
"It now appears that five separate zones at the CAGP each contain, or are likely to contain, more than 1Moz of gold resources - Abnabna, AF Gap, Esuajah South, Esuajah North and Fetish. In addition, there are a number of significant but underexplored other contenders for inclusion in this list."
"The Company has an excellent track record of growing its M&I Resources organically at an average rate of 1.6Moz per annum over the past three years and reserves at about 2.0Moz per annum over the past two years."
CAGP Resource Estimate
Extensive drilling on the Abnabna-Fobinso and the Esuajah South deposits during the past 18 months has enabled the re-estimation of mineral resources for those deposits. The resource estimates are tabled below and notes to the estimates are contained in Appendix 1.
The most significant change in the resources at Abnabna-Fobinso has been the increase in Measured mineral resources from 20.0Mt at 1.3g/t Au in the 2009 estimate to 42.9Mt at 1.2g/t (a 91% increase in contained gold). Inferred mineral resources have decreased from 16.3Mt at 1.0g/t to 4.6Mt at 1.2g/t and Indicated mineral resources are approximately the same at 23.3Mt at 0.9g/t Au, compared to 20.3Mt at 1.1g/t Au in the 2009 estimate.
The Esuajah South deposit changed significantly, from 6.9Mt at 1.7g/t Au Indicated resources to 14.5Mt at 1.8g/t Au Measured and Indicated mineral resources containing 818,000 ounces (60% Measured), representing a 117% increase in contained gold. Inferred mineral resources decreased by 91,000 ounces from 5.6Mt at 1.8g/t Au to 5.3Mt at 1.3g/t Au. Significantly, most of the increase in resources is attributable to the granite body being wider at depth than previously expected, resulting in an average of 2,000 ounces of contained gold per vertical metre to -220mRL (360m vertical). Below that depth the resource is constrained by lack of drill data.
Reserve Estimate CAGP
New pit designs have been completed for the Abnabna-Fobinso deposits and an initial pit design was completed for the Esuajah South deposit. The limits of the pit designs were nominally based on US$1,000 gold price optimisation shells. The Whittle optimisation inputs were based on the 2009 feasibility study up dated to reflect changes in mill-expected throughput rates, operating costs, the mining contract and the Government royalty of 5%. Reserves are reported at a 0.4g/t Au (previously 0.5g/t Au) cut-off for Abnabna-Fobinso and 0.5g/t Au for Esuajah South. Details of the reserve estimates are contained in Table 1 and 8 and Appendix 3.
Grumesa Resource Estimate
Further infill drilling was undertaken on the Kayeya gold deposit on the Grumesa Gold Project during 2008 resulting in a new mineral resource estimate being completed in December 2010.
A summary of the resources is tabled below and notes to the estimates are contained in Appendix 2.
The large, low-grade Kayeya gold deposit is amenable to low cost heap leach processing and the Company has applied for a Mining Lease with the aim of developing a modest satellite heap leach operation. Considerable potential exists for further resources, given that the upper 45m of the deposit as currently defined contains more than 12,000 ounces of gold per vertical metre and there is limited drilling below 45m. In addition, about a third of the deposit's 3sq km footprint remains under-explored.
Table 1: CAGP, Mineral Reserve Estimate Summary | ||||||||||
Deposit | Proven Reserves(1) | Probable Reserves(1) | Proven & Probable Reserves | W:O Ratio(2) |
||||||
Ore Mt |
Au g/t |
Au ,000 oz |
Ore Mt |
Au g/t |
Au ,000 oz |
Ore Mt |
Au g/t |
Au ,000 oz |
||
Abnabna-Fobinso | 40.2 | 1.2 | 1,541 | 12.3 | 0.9 | 345 | 52.5 | 1.1 | 1,885 | 2.5 |
Esuajah South | 7.5 | 1.8 | 433 | 1.3 | 1.8 | 75 | 8.8 | 1.8 | 508 | 7.6 |
Esuajah North | 11.9 | 1.0 | 390 | 11.9 | 1.0 | 390 | 1.2 | |||
Fetish | 13.7 | 1.1 | 490 | 13.7 | 1.1 | 490 | 2.5 | |||
Total | 47.7 | 1.3 | 1,974 | 39.2 | 1.0 | 1,300 | 86.9 | 1.2 | 3,273 | 2.8 |
Notes
- 0.4g/t Au cut-off applied to Abnabna-Fobinso and 0.5g/t Au cut-off applied to other deposits.
- Inferred mineral resources totalling 3.2Mt at 1.1g/t Au is considered as waste.
Mark Calderwood
Managing Director
About Perseus Mining Limited
Perseus Mining Limited (ASX/TSX: PRU) has forged a reputation as one of the West Africa's most successful gold explorers. Focused on under-explored gold belts in West Africa, Perseus is on track to become a producer by the third quarter of 2011 at its Central Ashanti Gold Project in Ghana. The Company plans to produce at the initial rate of 220,000 ounces of gold in year 1 in Ghana and plans to increase this to 300,000 ounces per annum by 2013.
Perseus is now also working on development of its Tengrela Gold Project in Côte d'Ivoire, with production targeted for late 2012. Tengrela has the potential to become a significant contributor in the Company's goal to develop into a 400,000 ounce per year gold producer by 2013.
With an average of 25,000m of drilling planned each month across its projects, Perseus will continue its strategy of rapidly increasing its resource and reserve base during the development of the CAGP and Tengrela.
In addition to its projects in Ghana and Côte d'Ivoire, Perseus retains a 25 per cent stake in Manas Resources Limited (ASX: MSR) which it spun off in 2008 as a focused Kyrgyz Republic gold explorer and developer. Perseus also has a 19.9% stake in, as well as a strategic alliance with, Burey Gold Limited (ASX: BYR), a listed exploration company focussed on Guinea, West Africa.
The information in this report that relates to the Abnabna-Fobinso, Esuajah South and Kayeya mineral resources is based on information compiled by Mr Aaron Green, who is a Member of The Australian Institute of Geoscientists. Mr Green is a full-time employee of Runge Limited. Mr Green has sufficient experience, which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking, to qualify as a Competent Person as defined in the 2004 Edition of the 'Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves'") and to qualify as a "Qualified Person" under National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101"). Mr Green consents to the inclusion in this report of the matters based on his information in the form and context in which it appears.
The information in this report that relates to the Abnabna-Fobinso and Esuajah South ore reserves is based on information compiled by Mr Chris Marissen, who is a Member of The Australasian Institute of Mining and Metallurgy. Mr Marissen is a Mining Engineer and a full-time employee of the Company. Mr Marissen has sufficient experience, which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking, to qualify as a Competent Person as defined in the 2004 Edition of the 'Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves'") and to qualify as a "Qualified Person" under National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101"). Mr Marissen consents to the inclusion in this report of the matters based on his information in the form and context in which it appears.
The information in this report that relates to exploration results and historic resources is based on information compiled by Mr Mark Calderwood, who is a Member of The Australasian Institute of Mining and Metallurgy. Mr Calderwood is a Director and full-time employee of the Company. Mr Calderwood has sufficient experience, which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking, to qualify as a Competent Person as defined in the 2004 Edition of the 'Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves'") and to qualify as a "Qualified Person" under National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101").
Mr Calderwood consents to the inclusion in this report of the matters based on his information in the form and context in which it appears. For a description of Perseus' data verification process, quality assurance and quality control measures, the effective date of the mineral resource and mineral reserve estimates contained herein, details of the key assumptions, parameters and methods used to estimate the mineral resources and reserves set out in this report and the extent to which the estimate of mineral resources or mineral reserves set out herein may be materially affected by any known environmental, permitting, legal, title, taxation, socio-political, marketing or other relevant issues, readers are directed to the technical report entitled "Technical Report - Central Ashanti Gold Project, Ghana" dated November 30, 2009 and the technical report entitled ''Technical Report - Tengrela Gold Project, Côte d'Ivoire'' dated September 02, 2010 in relation to the Central Ashanti Gold Project and the Tengrela Gold Project respectively.
Caution Regarding Forward Looking Information: This report contains forward-looking information which is based on assumptions and judgments of management regarding future events and results. Such forward-looking information includes but is not limited to information with respect to future exploration and drilling, procurement of financing, procurement of necessary regulatory approvals, the development of mines at the Central Ashanti Gold Project and Tengrela.
Forward-looking information involves known and unknown risks, uncertainties, and other factors which may cause the actual results, performance or achievements of the Company to be materially different from any anticipated future results, performance or achievements expressed or implied by such forward-looking information. Such factors include, among others, the actual market price of gold, the actual results of current exploration, the actual results of future exploration, , changes in project parameters as plans continue to be evaluated, as well as those factors disclosed in the Company's publicly filed documents.. The Company believes that the assumptions and expectations reflected in the forward-looking information are reasonable. Assumptions have been made regarding, among other things, the Company's ability to carry on its exploration and development activities, the timely receipt of required approvals, the price of gold, the ability of the Company to operate in a safe, efficient and effective manner and the ability of the Company to obtain financing as and when required and on reasonable terms. Readers should not place undue reliance on forward-looking information. Perseus does not undertake to update any forward-looking information, except in accordance with applicable securities laws.
Table 2: CAGP, Abnabna-Fobinso, Measured and Indicated Mineral Resources (>0.8g/t Au(1)) | |||||||||
Deposit | Measured Resources | Indicated Resources | Total Measured and Indicated Resources | ||||||
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
|
Oxide | 1.1 | 1.4 | 48,000 | 0.4 | 1.4 | 18,000 | 1.5 | 1.4 | 66,000 |
Transition | 0.8 | 1.4 | 36,000 | 0.3 | 1.4 | 16,000 | 1.1 | 1.4 | 51,000 |
Primary | 26.7 | 1.5 | 1,280,000 | 7.8 | 1.3 | 325,000 | 34.5 | 1.4 | 1,604,000 |
Total(2) | 28.6 | 1.5 | 1,364,000 | 8.6 | 1.3 | 358,000 | 37.2 | 1.4 | 1,722,000 |
Notes
- Reported at 0.8g/t cut-off above -100mRL and 1.2g/t below -100mRL).
- Rounding applied to totals.
Table 3: CAGP, Abnabna-Fobinso, Measured and Indicated Mineral Resources (>0.4g/t Au(1)) | |||||||||
Deposit | Measured Resources | Indicated Resources | Total Measured and Indicated Resources | ||||||
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
|
Oxide | 1.8 | 1.1 | 62,000 | 1.1 | 0.9 | 32,000 | 2.9 | 1.0 | 93,000 |
Transition | 1.1 | 1.2 | 42,000 | 0.7 | 1.0 | 22,000 | 1.8 | 1.1 | 64,000 |
Primary | 40.0 | 1.2 | 1,551,000 | 21.4 | 0.9 | 616,000 | 61.5 | 1.1 | 2,167,000 |
Total(2) | 42.9 | 1.2 | 1,655,000 | 23.3 | 0.9 | 669,000 | 66.2 | 1.1 | 2,324,000 |
Notes
- Reported at 0.4g/t cut-off above -100mRL and 0.8g/t below -100mRL).
- Rounding applied to totals.
Table 4: CAGP, Abnabna-Fobinso, Inferred Mineral Resources | |||||||||
Deposit | 0.8g/t Au(1) | 0.4g/t-0.8g/t Au(2) | Total Inferred Resources | ||||||
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
|
Oxide | 0.08 | 1.2 | 3,000 | 0.03 | 0.7 | 600 | 0.1 | 1.1 | 4,000 |
Transition | 0.02 | 1.3 | 900 | 0.02 | 0.6 | 400 | 0.04 | 1.0 | 1,000 |
Primary | 1.9 | 1.6 | 92,000 | 2.6 | 0.9 | 75,000 | 4.4 | 1.2 | 168,000 |
Total(3) | 2.0 | 1.5 | 96,000 | 2.6 | 0.9 | 76,000 | 4.6 | 1.2 | 173,000 |
Notes
- Reported at 0.8g/t cut-off above -100mRL and 1.2g/t below -100mRL).
- Reported at 0.4-0.8g/t cut-off above -100mRL and 0.8-1.2g/t below -100mRL).
- Rounding applied to totals.
Table 5: CAGP, Esuajah South, Measured and Indicated Mineral Resources (>0.8g/t Au(1)) | |||||||||
Deposit | Measured Resources | Indicated Resources | Total Measured and Indicated Resources | ||||||
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
|
Oxide | 0.05 | 1.9 | 3,000 | 0.01 | 1.2 | 300 | 0.05 | 1.8 | 3,000 |
Transition | 0.15 | 2.3 | 11,000 | 0.05 | 2.3 | 4,000 | 0.2 | 2.3 | 15,000 |
Primary | 6.8 | 2.0 | 439,000 | 4.8 | 1.9 | 289,000 | 11.7 | 1.9 | 728,000 |
Total(2) | 7.0 | 2.0 | 453,000 | 4.9 | 1.9 | 293,000 | 11.9 | 1.9 | 746,000 |
Notes
- Reported at 0.8g/t cut-off above -100mRL and 1.2g/t below -100mRL)
- Rounding applied to totals
Table 6: CAGP, Esuajah South, Measured and Indicated Mineral Resources (>0.4g/t Au(1)) | |||||||||
Deposit | Measured Resources | Indicated Resources | Total Measured and Indicated Resources | ||||||
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
|
Oxide | 0.05 | 1.9 | 3,000 | 0.01 | 0.9 | 400 | 0.06 | 1.7 | 3,000 |
Transition | 0.15 | 2.3 | 11,000 | 0.06 | 2.1 | 4,000 | 0.2 | 2.2 | 15,000 |
Primary | 8.1 | 1.8 | 471,000 | 6.1 | 1.7 | 330,000 | 14.2 | 1.8 | 800,000 |
Total(2) | 8.3 | 1.8 | 485,000 | 6.2 | 1.7 | 334,000 | 14.5 | 1.8 | 818,000 |
Notes
- Reported at 0.4g/t cut-off above -100mRL and 0.8g/t below -100mRL).
- Rounding applied to totals.
Table 7: CAGP, Esuajah South, Inferred Mineral Resources | |||||||||
Deposit | 0.8g/t Au(1) | 0.4g/t-0.8g/t Au(2) | Total Measured and Indicated Resources | ||||||
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
|
Primary | 2.7 | 1.7 | 146,000 | 2.6 | 0.9 | 79,000 | 5.3 | 1.3 | 224,000 |
Total(3) | 2.7 | 1.7 | 146,000 | 2.6 | 0.9 | 79,000 | 5.3 | 1.3 | 224,000 |
Notes
- Reported at 0.8g/t cut-off above -100mRL and 1.2g/t below -100mRL)
- Reported at 0.4-0.8g/t cut-off above -100mRL and 0.8-1.2g/t below -100mRL)
- Rounding applied to totals
Table 8: CAGP, Reserves | |||||||||||
Deposit | Proven | Probable | Total Reserve | Inferred Resource | Total Rock | Strip Ratio | |||||
Qty (Mt) |
Gold (g/t) |
Qty (Mt) |
Gold (g/t) |
Qty (Mt) |
Gold (g/t) |
Cont. Gold (Moz) |
Qty (Mt) |
Gold (g/t) |
Qty (Mt) |
(t/t) | |
Abnabna/AF Gap | 40.2 | 1.2 | 12.3 | 0.9 | 52.5 | 1.1 | 1.9 | 0.5 | 0.9 | 182.5 | 2.5 |
Esuajah South | 7.5 | 1.8 | 1.3 | 1.8 | 8.8 | 1.8 | 0.5 | 0.3 | 0.9 | 75.2 | 7.6 |
Fetish | - | - | 13.7 | 1.1 | 13.7 | 1.1 | 0.5 | 2.0 | 1.3 | 48.0 | 2.5 |
Esuajah North | - | - | 11.9 | 1.0 | 11.9 | 1.0 | 0.4 | 0.4 | 0.7 | 25.9 | 1.2 |
Total | 47.7 | 1.3 | 39.2 | 1.0 | 86.9 | 1.2 | 3.3 | 3.2 | 1.1 | 331.6 | 2.8 |
Notes
- 0.4g/t Au cut-off applied to Abnabna-Fobinso and 0.5g/t Au cut-off applied to other deposits.
- Inferred mineral resources totalling 3.2Mt at 1.1g/t Au is considered as waste.
Table 9: Grumesa Gold Project, Kayeya Indicated Mineral Resources (>0.6g/t Au) | |||||||||
Deposit | Measured Resources | Indicated Resources | Total Measured and Indicated Resources | ||||||
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
|
Oxide | 1.8 | 0.9 | 53,000 | 1.8 | 0.9 | 53,000 | |||
Transition | 1.2 | 0.9 | 35,000 | 1.2 | 0.9 | 35,000 | |||
Primary | 5.9 | 0.9 | 164,000 | 5.9 | 0.9 | 164,000 | |||
Total(1) | 8.9 | 0.9 | 252,000 | 8.9 | 0.9 | 252,000 |
Notes
- Rounding applied to totals.
Table 10: Grumesa Gold Project, Kayeya Indicated Mineral Resources (>0.4g/t Au(1)) | |||||||||
Deposit | Measured Resources | Indicated Resources | Total Measured and Indicated Resources | ||||||
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
|
Oxide | 7.4 | 0.5 | 121,000 | 7.4 | 0.5 | 121,000 | |||
Transition | 5.2 | 0.5 | 82,000 | 5.2 | 0.5 | 82,000 | |||
Primary | 12.5 | 0.7 | 268,000 | 12.5 | 0.7 | 268,000 | |||
Total(2) | 25.1 | 0.6 | 471,000 | 25.1 | 0.6 | 471,000 |
Notes
- Primary reported above a 0.4g/t Au cut-off, oxide/transition report above a 0.2g/t Au cut-off.
- Rounding applied to totals.
Table 11: Grumesa Gold Project, Kayeya Inferred Mineral Resources | |||||||||
Deposit | 0.6g/t Au | 0.4g/t-0.6g/t Au(1) | Total Inferred Resources | ||||||
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
Tonnes Mt |
Au g/t |
Au Ounces |
|
Oxide | 0.5 | 0.8 | 14,000 | 6.0 | 0.3 | 67,000 | 6.6 | 0.4 | 81,000 |
Transition | 0.3 | 0.7 | 6,000 | 2.7 | 0.4 | 31,000 | 2.9 | 0.4 | 38,000 |
Primary | 2.1 | 0.8 | 54,000 | 4.8 | 0.5 | 74,000 | 6.9 | 0.6 | 128,000 |
Total(2) | 2.9 | 0.8 | 74,000 | 13.5 | 0.4 | 173,000 | 16.4 | 0.5 | 247,000 |
Notes
- Primary reported above a 0.4g/t Au cut-off, oxide/transition report above a 0.2g/t Au cut-off.
- Rounding applied to totals.
Table 12: Total Mineral Resources (Including Reserves)
Deposit (cut-off g/t Au) |
Measured & Indicated | Inferred | ||||
Tonnes (million) |
g/t Au |
Ounces Au (,000) |
Tonnes (million) |
g/t Au |
Ounces Au (,000) |
|
CAGP-(Ayanfuri) (1) >0.8g/t |
71.2 | 1.4 | 3,307 | 24.4 | 1.5 | 1,144 |
CAGP-(Ayanfuri) (1) 0.4g/t - 0.8g/t |
47.1 | 0.7 | 1,012 | 25.3 | 0.7 | 538 |
Grumesa (1) 0.4 (2) |
25.1 | 0.6 | 471 | 16.4 | 0.5 | 247 |
Tengrela(3) 1.0g/t |
9.9 | 2.5 | 796 | 3.3 | 1.7 | 171 |
Tengrela(3) 0.5-1.0g/t |
5.6 | 0.8 | 135 | 3.6 | 0.7 | 86 |
Totals >0.8g/t (1.0g/t Tengrela) |
81.0 | 1.5 | 4,103 | 27.7 | 1.5 | 1,315 |
Totals >0.4g/t (0.5g/t Tengrela) |
158.8 | 1.1 | 5,721 | 73.0 | 0.9 | 2,186 |
Notes:
- Last updated in December 2010.
- Primary reported above a 0.4g/t Au cut-off, oxide/transition report above a 0.2g/t Au cut-off.
- Last updated in November 2010.
- The Company holds 90% of Ayanfuri, 90% of Grumesa and 80% of Tengrela after allowing for Government equity at mining stage.
Table 13: Total Mineral Reserves
Deposit | Proven | Probable | Total | ||||||
Tonnes (million) |
g/t Au |
Ounces Au (,000) |
Tonnes (million) |
g/t Au |
Ounces Au (,000) |
Tonnes (million) |
g/t Au |
Ounces Au (,000) |
|
CAGP-(Ayanfuri) 0.4g/t (1,2) |
47.7 | 1.3 | 1,974 | 39.2 | 1.0 | 1,300 | 86.9 | 1.2 | 3,273 |
Tengrela 0.55g/t (3) |
9.7 | 2.1 | 657 | 9.7 | 2.1 | 657 | |||
Total | 47.7 | 1.3 | 1,974 | 48.9 | 1.3 | 1,957 | 96.6 | 1.3 | 3,930 |
Notes
- >0.4g/t Au cut-off for Abnabna-Fobinso, >0.5g/t Au cut-off for all other deposits.
- Last updated in December 2010.
- Last updated in November 2010.
Table 14: Residual Mineral Reserves (Additional to Reserves)
Deposit (cut-off g/t Au) |
Measured & Indicated | Inferred | ||||
Tonnes (million) |
g/t Au |
Ounces Au (,000) |
Tonnes (million) |
g/t Au |
Ounces Au (,000) |
|
CAGP-(Ayanfuri) (1) >0.8g/t |
12.2 | 1.5 | 587 | 24.4 | 1.5 | 1,144 |
CAGP-(Ayanfuri) (1) 0.4g/t - 0.8g/t |
19.9 | 0.7 | 466 | 25.3 | 0.7 | 538 |
Grumesa (1,2) 0.4 (2) |
25.1 | 0.6 | 471 | 16.4 | 0.5 | 247 |
Tengrela(3) 1.0g/t |
3.0 | 2.1 | 200 | 3.3 | 1.7 | 171 |
Tengrela(3) 0.5-1.0g/t |
3.0 | 0.8 | 74 | 3.6 | 0.7 | 86 |
Totals >0.8g/t (1.0g/t Tengrela) |
15.2 | 1.6 | 787 | 27.7 | 1.5 | 1,315 |
Totals >0.4g/t (0.5g/t Tengrela) |
63.2 | 0.9 | 1,798 | 73.0 | 0.9 | 2,186 |
Notes
- Last updated in December 2010.
- Primary reported above a 0.4g/t Au cut-off, oxide/transition report above a 0.2g/t Au cut-off.
- Last updated in November 2010.
- The Company holds 90% of Ayanfuri, 90% of Grumesa and 80% of Tengrela after allowing for Government equity at mining stage.
APPENDIX 1:
Notes on the Abnabna-Fobinso and Esuajah South mineral estimates, CAGP, Ghana
- The Mineral Resource estimate for the Abnabna-Fobinso and Esuajah South gold deposits of the Central Ashanti Gold Project ("CAGP") was completed in December 2010 by Runge Ltd for Perseus Mining Ltd.
- The deposits are located within altered Lower Proterozoic Biriman (2.17-2.18 billion years) granitoid and meta-sediments. The granitoid hosted deposits range from 200 to 400m strike and 10 to 150m in width. The granitoids appear to be pervasively mineralised (0.1g/t to 2g/t) with higher grades associated with sheeted quartz veining. Meta-sediment hosted mineralisation is associated veining within 5m to 50m wide shear zones.
- The drill database for Abnabna-Fobinso contains 417 Reverse Circulation ("RC") drill holes totalling 33,231m and 667 diamond drill holes totalling 125,347m. In addition, there were 51 RAB holes totalling 2,930m. Sample recovery is considered to have been to industry standard for both RC and diamond drilling.
- The drill database for Esuajah South contains 25 RC drill holes totalling 2,330m and 141 diamond drill holes totalling 33,146m. Sample recovery is considered to have been to industry standard for both RC and diamond cored drilling.
- Pre 2006 RC drilling was routinely analysed for gold using a 0.5kg 24hr bulk cyanide leach method. 2006 to 2007 RC drill samples were analysed by 1kg 24hr bulk cyanide leach method with the tails of all samples with assays greater than 0.5g/t being fire assayed. Only the recovered grades of the bulk cyanide leach method were used in the resource estimate. 2006 to 2008 diamond and 2008 RC drill samples were analysed by 50g fire assay method. Standards, spikes, blanks and repeat samples have been randomly submitted during all drilling programs. Sufficient QAQC and data validation has been carried out to verify the integrity of the assay data.
- The relative position of all drill-hole collars is related back to the original mine grid using a total station theodolite. Holes are considered to be accurate to within 1m horizontally and 0.5m vertically. The surface topography of the deposits used for resource modelling was generated using lattice gridding of survey data points and is considered to be sufficiently accurate for the generation of an Indicated and Inferred mineral resource estimate. Down hole surveying is routinely used in the deeper percussion drilling and diamond core holes. The down-hole sample location data for the all zones is considered adequate to allow for the estimation of Measured mineral resources.
- The Abnabna-Fobinso and Esuajah South deposits have been partially exploited by mining.
- Drilling was carried out along north-south fences which were nominally spaced at 10m to 40m grid east intervals and at 10m to 40m centres. All drill-holes were inclined at between 25° and 60° at grid east and west azimuths. The gold value used for plotting and grade estimation was the first bulk cyanide leach determination or, in its absence, the first fire assay determination presented by the laboratory.
- Bulk densities were adopted from the CAGP database comprising 956 bulk density determinations within the mineralised envelope recently conducted by Perseus.
- Wireframes were constructed using cross sectional interpretations based on geology or a 0.2g/t Au cut-off grade.
- Samples within the wireframes were composited to 2.0m intervals in the Abnabna-Fobinso deposit and to 1.0m at the Esuajah South deposit. Various high grade cuts of between 10g/t and 40g/t were applied to the composite values. High grade cuts were determined from statistical analysis of composite data.
- Surpac block models were used for the estimate with block sizes determined from drill hole spacing and lode geometry. Sub cells were used to ensure accurate volume representation of the mineralised lodes.
- The deposits were interpolated using Ordinary Kriging (OK) grade estimation. Small pods at Esuajah South were estimated using Inverse Distance Squared (ID2) interpolation due to the sparsity of data within them. The estimates were run in three passes. The search ellipse was based on kriging parameters defined from directional variography, and lode geometry. A first pass radius of between 40m and 60m was used. This was increased to 60m and 120m for the second pass. A third and final pass was used on blocks not filled in the first two passes and used search radiuses of between 120m and 220m. The majority of blocks were estimated in the first two passes.
- The Mineral Resource was classified as Measured, Indicated or Inferred based on the quality of the drilling data and the demonstrated geological and grade continuity defined by recent drill programs.
APPENDIX 2:
Notes on the Kayeya mineral resource estimate, Grumesa Gold Project, Ghana
- The mineral resource estimate for the Kayeya gold deposit was completed in December 2010 by Runge Limited for Perseus Mining Ltd.
- The Kayeya prospect is located within a sequence of Lower Proterozoic Biriman (2.17-2.18 billion years) mid to upper Tarkwaian epiclastics referred to as the Kayeya Conglomerate. The Kayeya Conglomerate appears to be gold enriched (³ 0.2gm Au/t) over an area of some 3.0 sq km. Gold mineralisation plunges gently to the north at 0-30°. The western zones of mineralisation have relatively steep dips at 60-80° to the west, while the eastern zones exhibit flatter dips at 10-30° to the north. Visible gold in drill core recovered from the Kayeya Prospect generally occurs on the margins of quartz stringers or in biotite rich micro-fractures. Overall the correlation between gold and quartz veining is poor. Sulphides are rare.
- The drill database contains 774 Reverse Circulation ("RC") drill holes totaling 45,975m and 24 diamond holes totalling 2,111m. Sample recovery is considered to have been good for both RC and diamond cored drilling.
- Samples were prepared and analysed at SGS Laboratory Services Ghana or Transworld Laboratories, both in Tarkwa, Ghana. All samples followed a standard path of drying, crushing and grinding. Two analysis methods were then used depending on the drilling method used. RC samples were subject to a 24 hour bottle roll and AAS analysis BLEG, while diamond core samples were subjected to a fire assay and AAS analysis. QAQC procedures involving standards, blanks and repeat samples have been randomly submitted during all drilling programs.
- The relative position of all drill-hole collars is survey-controlled, with each hole being surveyed or related back to a pre-existing 50m by 25m grid set out using a total station theodolite. Holes are considered to be accurate to within 1m horizontally and 0.5m vertically. The surface topography of the Kayeya prospect used for resource modelling was generated using lattice gridding of 50m by 25m survey data points and is considered to be sufficiently accurate for the generation of Indicated and Inferred Mineral Resource estimates. Bottom-of-hole single shot surveys using acid tubes or a single shot Eastman camera were generally a systematic part of the process of deeper percussion drilling at the Kayeya prospect. However, the surveys were limited to dip measurements only. Holes with significant deviations were also surveyed at a second up-hole interval. As the blade RC holes did not penetrate hard rock, the deviation of those holes was only measured when the drill holes penetrated significantly into hard rock. The down-hole sample location data for the Kayeya prospect is considered adequate to allow for the estimation of Indicated and Inferred Mineral Resources.
- The Kayeya resource area extends over a strike length of 3,250m from 89,000mN to 92,250mN and includes the 150m vertical interval from surface at 1,130mRL to 980mRL.
- The resource estimate database includes assay and lithological data compiled on drilling, logging and assaying of the samples recovered from the 718 RC (blade and percussion) and 12 diamond holes within and projected across, the Kayeya deposit. Drilling was carried out along east-west fences which were nominally spaced at 20m to 40 metre grid north intervals and at 10 to 30 metres centres. All drill-holes were inclined at between 50° and 60° at grid west and east azimuths. The reporting of gold values used for plotting and grade estimation was the first Bulk Cyanide Leach determination or, in its absence, the first fire assay determination presented by the laboratory.
- A total of 106 bulk density determinations have been undertaken on drill core from the Kayeya prospect. Bulk densities determinations were undertaken by SGS, Leo Shield and by Goldfields of South Africa. Average bulk densities were determined as 1.7t/m3 for Oxide, 2.3t/m3 for Transition and 2.7t/m3 for Fresh.
- Wireframes were constructed using cross sectional interpretations based on a 0.2g/t Au cut-off grade.
- Samples within the wireframes were composited to even 2.0m intervals. High grade cuts were applied to gold values, based on statistical analysis and varied from 2g/t to 9g/t.
- A Surpac block model was used for the estimate with a block size of 20m NS x 10m EW x 5m vertical with sub-cells of 10m x 5m x 2.5m.
- Ordinary Kriging (OK) grade interpolation using kriging parameters defined from directional variography was used to estimate block grades. Small pods having sparse data were estimated using ID2 interpolation. The estimate was run in 3 passes using an orientated search ellipse with a first pass radius of between 50m and 120m and a second pass radius of between 70m and 160m with a final third pass of 90m to 250m. The majority of blocks were estimated in the first 2 passes.
- The Mineral Resource was classified as Indicated and Inferred as a consequence of the geological and grade continuity defined by historic and recent drilling programs.
- No assumptions have been made about the mining and processing methods in the current resource estimation.
APPENDIX 3:
Notes on the Abnabna-Fobinso and Esuajah South Reserve Estimates, CAGP, Ghana
- The mineral reserve estimate for the Abnabna-Fobinso and Esuajah South gold deposits was completed in December 2010 by Chris Marissen of Perseus Mining Ltd.
- The block models adopted for the estimate were generated by consultants Runge Ltd using the general mining package Surpac. The models for Abnabna-Fobinso and Esuajah South were completed in December 2010.
- Pit optimisations were run using Whittle 4D software with inputs derived from the 2009 Feasibility study updated where necessary to reflect changes in Government royalties (now 5%), mining costs based on the current mining contract and scaled to reflect deeper pits, increased mill throughput rates and updated operating costs. Optimisations where run at varying gold prices ranging from 500 to 2000 US$/oz.
- Pit designs were completed using geotechnical pit slope angles as derived from the 2009 feasibility study contributed to by the consultants Coffey Mining. The base of pits was nominally referenced in Abnabna-Fobinso to the US$1000 optimisation shell and Esuajah South US$950 optimisation shell.
- A cut off grade for ore was set at 0.4g/t Au for Abnabna-Fobinso and 0.5g/t Au for Esuajah South due to the increased ore haulage distance. A mining dilution factor of 3% was applied, with dilutive waste assumed to have no gold. The dilution factor is a reflection of the large ore body widths.
- Inferred mineral resources are considered as waste.
- The Mineral Reserve was classified as Proven and Probable as a consequence of the classification of the equivalent mineral resources as Measured and Indicated.
For further information:
Perseus Mining Limited, ABN 27 106 808 986, 30 Ledgar Road, Balcatta, Western Australia, 6021, PO Box 717, Balcatta, WA, 6914, Telephone: (618) 9240 6344, Facsimile: (618) 9240 2406, Email address: [email protected], Website: www.perseusmining.com
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