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Cambodian Gold Project

Cambodian Gold Project

The Okvau Gold Deposit is located in the Mondulkiri Province approximately 265 kilometres north-east of the capital Phnom Penh.  The topography is undulating with low relief 80 to 200 metres above sea level. The area is sparsely populated with some artisanal mining activity.  Existing dirt roads and tracks provide for sufficient access for the exploration activities.

The project area has key similarities (geology and geochemistry) with the world class Tintina Gold Belt (Alaska-Yukon) which host deposits such as:

- Donlin Creek 38Moz @ 2.3g/t
- Fort Knox 10Moz @ 0.8g/t
- Pogo 6Moz @ 18g/t
- Livengood 20Moz @ 0.6g/t

  • Independent JORC resource estimate at the 100% owned Okvau deposit of 15.6Mt at 2.4g/t gold for 1.2 million ounces gold
  • 93% of resource estimate classified as ‘Indicated’
  • Indicated component of resource estimate is from surface to less than 300 metres. Depth and geometry is amenable to open pit mining
  • Okvau remains open to the north-east, south-east and at depth with scope for further resource expansion (refer Figure One and Two)
  • 25,000 metre regional Reverse Circulation (“RC”) drilling program continuing

The resource estimate includes the drilling completed by the Company on the Okvau gold deposit during 2012 which was a combination of infill and extensional drilling. This drilling provided better delineation of high grade gold zones.

Renaissance engaged SRK Consulting (“SRK”) of Perth, Australia to complete an independent estimation of the mineral resources for the Okvau gold deposit.  The SRK March 2013 Resource estimate for the Okvau gold deposit is shown below:

Notes:

This Mineral Resource estimate for the Okvau Gold project was prepared by Robin Simpson of SRK Consulting (Australasia) Ltd. Mr Simpson is a Member of the Australian Institute of Geoscientists (AIG), and has sufficient experience 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 by the 2004 edition of the "Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves". Mr Simpson consents to the inclusion of the matters based on his information in the form and context in which it appears.

Mineralisation remains open to the north-east, south-east and at depth. Accordingly, the reported resource estimate is considered as an interim resource and potential exists to further expand the resource base.

The resource estimate covers approximately 500 metres strike and 250 metres width of the mineralised vein system. The resource estimate utilised 90 diamond drill holes totalling 28,156 metres. Given historical local mining activity, the resource estimate has excluded any mineralisation from surface to 10 metres vertical depth.

For the component potentially amenable to open pit mining, a lower cut-off grade of 0.65g/t gold is considered appropriate based on preliminary cost benchmarking undertaken by the Company.

As shown below, the Okvau deposit has a consistently high gold endowment per vertical metre.

Okvau Gold Deposit - Gold ounces per vertical metre

Renaissance aims to establish a multi-million ounce gold project at Okvau in Cambodia and is currently undertaking a 25,000 metre RC drilling program targeting high priority prospects within close proximity of the Okvau gold deposit.

The Company believes this new resource estimate for the Okvau gold deposit and the results from recent exploration undertaken confirm the potential for the Company to establish a new gold district.

Okvau Gold Deposit: Resource Wireframe

Okvau Gold Deposit: Resource Block Model (looking South West)

Okvau Exploration License Area

Okvau North Prospective Corridor

Cambodia Project Location

Appendix One | JORC Compliant Resource Estimate Parameters

The gold resource estimate completed at Okvau has been undertaken by SRK Consulting based in Perth, Western Australia.  The SRK March 2013 Resource estimate for the Okvau gold deposit is shown below:

*     Tonnes are rounded to nearest 0.1 Mt, grade to 0.01 g/t, and contained gold to 10,000 oz. Totals may appear different from the sum of their components because of rounding
** The Inferred resources are reported at a 0g/t gold cut-off as volumes are already quite restricted by a 2.0 g/t gold threshold

Based on the confidence in geological continuity, confidence in data quality, and the sampling density, SRK classified the component of the estimation above -150 mRL as Indicated. Below -150 mRL, the estimate of the higher grade Okvau Deeps component was based on fewer samples and more widely spaced intersections, so SRK classified this component as Inferred.

Gold mineralization at Okvau is associated with pyrrhotite and arsenopyrite veining within a fault zone system that transgresses diorite and hornfelsed lithologies. Moderate to high grade gold mineralization is located within both the main shears and secondary linking faults and splays. 

All samples in the database used for resource estimation are from diamond drilling. There are 90 holes in the Okvau drill hole database, for a total of 28,156 m. Intersection spacing is typically 25m by 25m. Sampling is generally on 1m or 2m intervals, for a total of 21,026 samples. All sampling has been conducted on sawn half core (NQ2). Blind QAQC inserted every 25 drill samples, including blanks and certified standard.  The samples from the first 9 drill holes (DD06OKV001 - DD06OKV009) were assayed by Mineral Assay and Services Co, Thailand. The remaining samples were all assayed by Australian Laboratory Services in Vientiane, Laos. All laboratory rejects have been retained and are in storage. All gold assaying done by 30g fire assay. 

As part of the data quality review, in February 2013 SRK visited the Okvau site, the sample preparation laboratory in Phnom Penh, and the primary assay laboratory in Vientiane (Laos). SRK also reviewed previous reports, and the QA/QC results for Okvau. SRK’s conclusion from these assessments is that there are no concerns about data quality that would be serious enough to downgrade the majority Indicated classification, which was assigned according to the sampling density and confidence in geological continuity.

The methods and parameters used for the estimation are summarised below:

  • The mineralisation domain to constrain estimation was modelled using Leapfrog software, and based on a 0.4 g/t grade shell. Anisotropy for constructing the grade shell was set up to follow the orientation of key structural controls interpreted by Dr Stephen King of Solid Geology Pty Ltd in previous studies of the Okvau deposit. Restrictions were added to prevent the grade shell projecting too far beyond the limits of the diorite (the main lithological control on mineralisation).
  • Composite length of 2m.
  • Variogram model fitted via a Gaussian transform of the composite grades.
  • Block size 10m x 10m x 5m
  • Block grades estimated by Ordinary Kriging.
  • Composite grades were capped at 50 g/t if a composite used for estimation was more than 10 m from the block being estimated. Composites within 10m were uncapped.
  • A constant density factor of 2.9 was used to convert volumes to tonnes.
  • Following guidance from Renaissance, SRK depleted block grades in the first 10m below topography to 0, to account for intensive near-surface artisanal mining.
  • Uniform Conditioning, based on an assumed Selective Mining Unit of 5m x 5m x 5m, was applied to the Ordinary Kriging model, to give a better quality prediction of the grade tonnage curve.
  • Based on preliminary pit optimisation work done by Renaissance, reporting of the model was restricted to blocks from -150 mRL and above (i.e. about 300m below surface).
  • Also from the preliminary optimisation work, a cut-off grade of 0.65g/t was chosen as the base case for reporting the resource estimation results.
  • Below the floor set at -150 mRL, SRK identified three zones where high grade intersections could be correlated between several drill holes. SRK modelled these zones using a 2.0 g/t grade shell, and added this “Okvau Deeps” component to the resource model.
  • Block grades for the Okvau Deeps were estimated by Ordinary Kriging. No Uniform Conditioning was applied. Within the grade shells, the Okvau Deeps are reported at a zero cut-off, because the volumes are already quite restricted by the 2.0 g/t threshold, and because this material is more likely to be extracted by underground mining methods.

by http://www.renaissanceminerals.com.au/

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