GGG Resources plc

GGG Resources plc

August 15, 2011 04:13 ET

GGG Resources plc: JORC Resource Update

Bullabulling Phase One Drilling Programme delivers 2.60 million Ounces JORC Compliant Resource

LONDON, UNITED KINGDOM--(Marketwire - Aug. 15, 2011) - GGG Resources plc (AIM:GGG)(ASX:GGB)


  • New JORC resource estimate from Phase One drilling of 2,603,000 ounces of gold at 1.03 g/t Au at a 0.5 g/t cut off.

  • 711,700 ounces converted from Inferred to Indicated Resource status.

  • 35,000 metres of Phase One infill drilling focussed on the 2.3km area between Bacchus and Phoenix pits.

  • Bullabulling has now been partially re-drilled to JORC (2004) standard to enable the JV to move from JORC resources to reserves over time.

  • Phase Two 70,000 metres infill drilling programme is currently underway aiming to upgrade a substantial portion of the current 1.9 million Inferred Resources to Indicated status in Q1 2012 so that an initial JORC ore reserve can be estimated.

  • Additional 20,000 metre exploration drill programme is also in progress targeting Gryphon, Kraken, Minotaur and Edwards on southern extension of the Bullabulling Trend.

  • Preliminary Project optimisation studies indicate potential for a high conversion rate from resource category to reserve category once the project economics have been finalised.

Mineral Resource Estimate Overview

The Phase One JORC (2004) compliant Mineral Resource estimate for the Bullabulling Gold Project near Coolgardie, Western Australia has been updated to 78.84 Mt at 1.03 g/t Au (2.60 million ounces contained gold) using a 0.5 g/t cut-off (Indicated and Inferred). The new mineral resource has been estimated to the 200RL, approximately 230m below surface, and remains open at depth and to the south.

The Phase One drilling programme, totalling approximately 35,000 metres, which primarily comprised QAQC (confirmation drilling) was completed in mid May 2011. Through a planned programme of twinning and the infill of previous drill holes, the project's resource consultant, the Snowden Group ("Snowden"), which is based in Perth, has been able to confirm the historic drill data as being statistically valid for use in a new resource estimate. Most of the Phase One drilling intersected known mineralisation in the existing CSA Global resource estimate which was prepared in mid-August 2010. Subsequent statistical studies on defining the drill spacing for Indicated and Inferred Resources were recently completed and the recommendations published recently (Monday 8th August 2011). The drill spacing recommended by Snowden for defining Indicated Resources has been set at 75m north-south and 35m east-west which has been used to classify the new resource estimate.

The previous reported JORC (2004) compliant mineral resource was an Inferred Resource of 41,517,000 tonnes at 1.48 g/t Au (1.98 million ounces of contained gold) at a 0.7 g/t Au cut-off to an assumed economic mining depth of 315m RL, approximately 120m below surface. The same resource at a 0.5 g/t Au cut off is an Inferred Resource of 75.013 MT at 1.08 g/t Au (2.61 million ounces of contained gold).

The updated resource estimate for the Bullabulling Project, including the new QAQC drilling, was completed by Snowden Group (a summary letter describing the data and techniques used and the resource estimate is appended). The estimation used assays from all the historic reverse circulation (RC) and diamond drill hole data, but excludes the RAB drilling data (previously included in the August 2010 resource estimate completed by CSA Global), over a 9 km2 area covering the Bullabulling Trend (Figure 1).

Multiple Indicator Kriging ("MIK") was used to establish the resource estimate, after the data were unfolded, using Datamine software. Variography carried out on the unfolded data provided ranges of up to 208m along strike and 108m down dip. These ranges were then used to design the primary search ellipse dimensions used in the modelling, which were 50m along strike, 25m down dip and 15m across strike. The variography reconciles well with the orientations of mineralised shoots derived from the recent structural study.

The updated Bullabulling Trend resource estimates by Snowden (at a 0.5g/t Au cut off) are listed in Table 1. The Gibraltar estimate was complied by CSA in 2010 while the Laterite Dumps estimate was compiled from data taken from previous company reports dated 1998.

Recent feasibility studies on processing cost and mining cost estimations suggest a 0.5 g/t Au cut off is appropriate for this project at current gold prices and this, and future resource estimates, will be quoted at this cut off.

Table 1. The Bullabulling Mineral Resource (August 2011) at 0.5 g/t cut off (JORC 2004)
Cut Off
Class Tonnes
Bullabulling Laterite 0.5 Inferred 1.6 0.89 45,700
Bullabulling Fresh 0.5 Indicated 21.3 1.01 691,000
0.5 Inferred 50.9 1.03 1,683,900
Bullabulling Trend Total 73.8 1.02 2,420,600
Gibraltar 0.5 Inferred 4.5 1.12 161,900
Laterite Dumps 0.5 Indicated 0.5 1.2 20,700
Grand Total 78.8 1.03 2,603,100
Note: The resource is quoted for blocks with a grade of greater than 0.5 g/t and the tonnage figures for the fresh mineralisation have been discounted by 7% to allow for the impact of barren pegmatite dykes.

Commenting on the independent JORC compliant mineral resource estimate, Jeff Malaihollo, GGG's Managing Director said:

"The Phase One JORC update demonstrates that Bullabulling is a very large and highly continuous system capable of achieving an initial ore reserve of over 1 million ounces of gold. The JV has made some assumptions on costs to optimise the pits based on the current resource update. Future drilling will be done primarily within these optimised areas which should translate to a high conversion of resources to reserves.

The Phase Two drilling programme should run to the end of 2011 and this we expect this to deliver an upgrade of portions of the Inferred Resource to higher categories. Drilling is also in progress on exploration targets at the southern extension of the Bullabulling Trend such as Gryphon, Kraken, Minotaur and Edwards, which we expect will provide additional resources."

The resource estimate was reviewed statistically, checked on plan and section and compared against the ore that was previously mined from the Bacchus North and South pits. The reconciliation against the ore mined was good with 3,679,000 tonnes at 1.39 g/t Au predicted by the estimate compared to 3,040,000 at 1.59 g/t Au reported as mined. The difference in tonnes and grade is due to the different block sizes used for mining compared to the resource estimate, with the larger block size used for the estimate resulting in a lower average grade, but higher tonnes for a similar number of ounces.

Reconciliation with previous resource estimate

There are a number of important differences between the CSA Global estimate that was published in August 2010 and the current Snowden estimate that makes comparing them difficult.

The Snowden resource estimate excludes all previous RAB drilling (4,485 holes for 127,888 metres) and excludes the Gibraltar resource, which accounts for 162,000 ounces of gold at a 0.5 g/t Au cut off. The areas modelled are therefore significantly different with the CSA model covering a larger area including Gibraltar and areas with RAB drilling (Figure 1). Snowden will now work on a separate resource estimate for Gibraltar, which will require a different block size and search orientations.

Snowden also concluded that pegmatite and other late stage dykes comprise about 7% of the total number of metres drilled in the Phase One drilling. They have therefore reduced the reported resource estimate tonnage and consequently contained ounces of gold by 7% to take account of dilution due to unmineralised pegmatite dykes. In contrast the CSA August 2010 estimate had no reduction for the pegmatite dykes as the model already assigned no grade to the unmineralised dykes.

The CSA model used an Ordinary Kriged estimation technique with no top cut applied to the input data and was reported at a 0.7 g/t Au cut off whereas the Snowden estimate used a Multiple Indicator Kriged estimation technique that statistically reduces the influence of high grade gold outliers and is reported at a 0.5 g/t cut off. This has increased the tonnes and reduced the average grade of the reported resource estimate.

The Snowden model is effectively constrained to a maximum depth of 230m, whereas the CSA estimate was constrained by to an area above the 315 RL, which equates to a depth of 120m.

The Snowden model uses a slightly larger block size of 25x10x5m compared to a 20x10x3m block size used by CSA. The larger block size will tend to lower the average grade and increase the tonnes.

The material bulk densities used by Snowden are 1.8 for oxidised and 2.9 for primary compared to 1.8 for oxidised and 2.6 for primary in the CSA model. The higher bulk densities used in the Snowden model will increase the tonnes and consequently ounces of gold in the fresh material.

The two estimates, when compared over a similar area and depth, give similar results when the differences in bulk densities and block size are taken into account.

Preliminary Project Optimisation

Four optimisations scenarios were developed to check the new resource estimate and to assess the economic potential of the Project. The optimisations were carried out using a spot gold price (US$1,500 and exchange rate of US$1.07), recovery of 92.5%, a discount rate of 8% and process rates of 3.5, 5.0, 7.5 and 10 million tonnes per annum ("mtpa"). No mining dilution was applied on the basis that the MIK resource model incorporates some degree of dilution and a mining recovery of ore 95% was used.

All scenarios returned positive economics and all scenarios mine a main pit 3.1 km long and 180m deep and a second pit at Bonecrusher that is 1.0 km long and 120m deep (Figure 2). The scenarios provide between 9-13 year mine life, with potential ore reserves of over 1 million ounces of gold, which equates to a resource to reserve conversion of 55-80%. The stated ore reserve target for the Project of 1.0 million ounces is expected to be achieved. The annual production range is 105,000 to 240,000 ounces of gold at an average grade of from 0.8 to 1.0 g/t Au and the strip ratio ranges from 3.4 to 2.6. Importantly, all scenarios include a significant proportion of the new Indicated and Inferred Resources, which means with infill drilling these resources will convert directly to reserves. Consequently, confidence of meeting the new reserve targets is high.

If new mineralisation can be found at the exploration targets to the south (Figure 2) or at depth the project economics will continue to improve.

Future work plan

There is now less than 45,000m of infill drilling required to convert a significant portion of Inferred Resources to Indicated Resources. This infill drilling should be completed by the end of 2011.

The exploration targets in the south of the Bullabulling Trend at Sphinx, Medusa, Edwards, Gryphon, Kraken and Minotaur (Figure 2) will also be drilled during this period which should add to the current resource base. A new resource estimate will be undertaken by Snowden once this phase of drilling has been completed.

In addition we are advancing the following;

  • Preliminary engineering design

  • Capital and operating cost estimates

  • Optimisation and ore reserve estimation

  • Updating and upgrading resource estimate based on Phase Two drill programme

  • High grade deep exploration drilling

  • Feasibility study

Competent Person Statement

The information in this letter/report that relates to the Exploration results, the 1998 Mineral Resource estimate and data that was used to compile the 2010 and 2011 Mineral Resource estimates is based upon information compiled by Dr. Jeffrey Malaihollo who is a full-time employee of the Company and Fellow of The Australasian Institute of Mining and Metallurgy and a fellow of the Geological Society of London. He is qualified as a Competent Person under the Code for the Reporting Mineral Exploration Results, Mineral Resources and Mineral Reserves, 2004 ("The Reporting Code") prepared by the Australasian Institute of Mining and Metallurgy and the Australian Institute of Geoscientists. Jeff Malaihollo consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.

The information in this letter/report that relates to the 2010 Mineral Resource estimate is based on information compiled by Steve Hodgson. Steven Hodgson is a member of the Australian Institute of Geoscientists (MAIG) and has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity to 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". Steven Hodgson is a full-time employee of CSA Global Resource Industry Consultants. Steven Hodgson consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.

The information in this letter/report that relates to the 2011 Mineral Resource estimate is based on information compiled by Richard Sulway. Richard Sulway is a member of the Australasian Institute of Mining and Metallurgy (MAusIMM) CP and has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity to 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". Richard Sulway is a full-time employee of Snowden Mining Industry Consultants Pty Ltd. Richard Sulway consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.

Maps showing the JORC areas and pit optimised areas referred to in this announcement is available on the version of this release available on the Company's website.

Glossary of Technical Terms

Assay Quantitative analysis of a substance to determine the proportion of some valuable constituent
Au Gold
Cut off Limit
g/t Grams per tonne
JORC Joint Ore Reserves Committee
Indicated resource In situ Mineral Resource calculated with a moderate confidence level to which economic parameters have not been applied
Inferred resource In situ Mineral Resource calculated with a low confidence level to which economic parameters have not been applied
Km kilometres
Laterites Soil types rich in iron and aluminium formed in hot and wet tropical areas
M Metres
Measured resource In situ Mineral Resource calculated with a high confidence level to which economic parameters have not been applied
Multiple Indicator Kriging A version of indicator kriging working with a family of indicators
Ordinary Kriged method Geostatistical method to interpolate the value at an unobserved location from observations of its value at nearby locations
Pegmatite A very coarse-grained, intrusive igneous rock
QAQC Quality Assurance / Quality Control
RAB Percussion (pneumatic) Rotary Air Blast drilling
RC Reverse Circulation drilling
RL Reduced Level
Variography The degree of spatial dependence

To view Figure 1: Areas covered by the CSA resource estimate (2010) in red and black compared to the Snowden estimate (2011) in black only, please visit the following link:

To view Figure 2: Drill location plan showing potential optimised pit outlines for the various resource target areas along the length of the Bullabulling Trend, please visit the following link:

Contact Information

  • Dr. Jeffrey Malaihollo
    MD, GGG Resources plc (UK)
    + 44 1992 531820

    Neil Boom
    MD, Gresham PR Ltd (UK).
    + 44 7866 805 108

    David McArthur
    GGG Resources plc (Australia)
    41 Stirling Highway
    Nedlands, WA 6009
    +61 8 9423 3200

    Westhouse Securities Limited (UK Nominated Adviser)
    Tom Price / Martin Davison
    + 44 20 7601 6100

    Collins Stewart Europe Limited (Broker)
    John Prior / Adam Miller
    + 44 20 7523 8350

    David Brook
    Professional Public Relations (Australia media)
    +61 8 9388 0944/ +61 433 112 936