Total exploration expenditure in 2009 amounted to $199.9m, of which $91.6m was spent on greenfield exploration, $80.8m on brownfield exploration and the balance of $27.5m on pre-feasibility and feasibility studies. The main aim of both AngloGold Ashanti’s greenfield and brownfield exploration programmes is to identify new attributable resource ounces of gold.
Greenfield exploration activities were undertaken in Australia, China, North and South America, Democratic Republic of the Congo (DRC), Middle East and North Africa (MENA), Russia, Sub-Saharan Africa and South East Asia during 2009. A total of 183,481m of diamond, reverse circulation, and aircore drilling was completed in testing existing priority targets and in the delineation of new targets in Australia, Colombia, the DRC and Canada.
Greenfield activities in Russia, China, Sub-Saharan Africa, MENA and South East Asia were undertaken predominantly through joint ventures and strategic alliances. The principal objective of the greenfields exploration team is value creation, including the discovery of new long-life, low-cost mines that maximise shareholder value. Discoveries and ground positions that do not meet certain investment criteria will be joint-ventured or divested to maximise the return on investment in exploration.
|Country||Greenfields exploration expenditure 2009 (%)||Metres drilled 2009 (m)|
In 2010, total exploration expenditure of some $270m is planned, with $86m to be spent on greenfield exploration and $78m allocated to pre-feasibility studies at La Colosa in Colombia, and feasibility studies at Tropicana in Australia and the Central Mongbwalu deposit in the DRC and associated expenditures. Of the remaining balance, $91m is planned to be spent on brownfield exploration and $15m in terms of the De Beers joint venture focusing on exploration on the continental shelf.
AngloGold Ashanti’s greenfield exploration strategy is based around building, growing and maintaining a pipeline of projects that are progressed through the stages of exploration, from initial ground selection to discovery, resource definition and drill-out. Exploration is conducted by AngloGold Ashanti in its own right (100%), through joint ventures and strategic alliances. Important components for new discoveries and effective resource targeting include securing new search spaces, strategic landholdings and a balanced project portfolio.
The current portfolio lies within the target range of 10-20% of the exploration investment in frontier terranes, 60-70% in emerging terranes, with the remainder invested into terranes of known gold endowment. The estimated breakdown for 2009 is illustrated below.
Significant achievements for 2009 include the successful completion of the pre-feasibility study of the Tropicana-Havana deposit and board approval for a full feasibility study. Regional exploration was advanced over the large Tropicana joint venture and wholly owned AngloGold Ashanti project in the Tropicana Fold Belt.
Significant advances were made in diversifying the geopolitical and terrane risk of AngloGold Ashanti’s greenfield exploration portfolio in 2009. Entry into new jurisdictions was achieved during the course of the year with rapid progress made in the delineation of exploration targets and their advancement to the licence application or drill target definition stage in several countries.
The global footprint of greenfield exploration activity underwent significant change in 2009. During the course of the year, AngloGold Ashanti entered into a number of new joint ventures and strategic alliances in Canada, Brazil, Gabon, the Middle East and North Africa, while downsizing in China and Russia. These new ventures include the Superior joint venture with Laurentian Goldfields and the Baffin Island joint venture with Commander Resources in Canada; the Thani Ashanti strategic alliance in the Middle East and North Africa with Thani Investments; and the Sub-Saharan Africa Kele & Mase joint ventures with XDM Resources in the Solomon Islands. AngloGold Ashanti has also re-entered the Sub-Saharan Africa region via a joint venture with Dome Ventures in Gabon. An exploration alliance was signed in Brazil with Horizonte Minerals to explore the Santana and Campestre projects.
A number of targets for greenfield exploration were missed in 2009, especially those relating to resource drilling and pre-feasibility studies at La Colosa and Gramalote in Colombia and at Central Mongbwalu in the DRC. The total number of metres drilled in 2009 was significantly lower than in 2008, a result of delays in the approval of the necessary environmental permits in Colombia, the requirement to renegotiate the joint venture terms for the mineral licence in the DRC, the withdrawal from projects in Russia and the rejection of mineral applications in China.
Initiatives to enhance the success of the greenfields exploration team included a rigorous assessment of the existing exploration portfolio. The work focussed on establishing what AngloGold Ashanti consider the right percentage balance between frontier, emerging and known geologic terranes. As a consequence the team is well positioned to increase metres drilled on both existing and new projects that are close to and at drill ready stage in 2010.
To further improve the decision making processes in project and portfolio management, the company is moving to a uniform global portfolio management process that will encompass both technical and commercial gating elements.
Greenfield exploration was completed by AngloGold Ashanti and its joint venture partners B2Gold, Glencore International and Mineros S.A. During 2009 systematic regional exploration for precious and base metals was undertaken over an area of 10,211km². During the year, 110 new targets were field generated with two drilled. Since 2004, the investment in exploration has generated 714 new exploration targets, of which 39 were brought to drill stage and 24 drill tested. Two of these targets are now projects at advanced study stages and contain initial JORC compliant resources of 14.4Moz of gold.
At Gramalote (51% B2Gold, 49% AngloGold Ashanti), the joint venture partners are presently in discussions to define the future of the project.
At the wholly owned La Colosa project; AngloGold Ashanti received a resolution on 20 October 2009 from the Ministry of Environment and Territorial Development, which allowed initiation of exploration permitting procedures before the regional environmental authority Cortolima. Once permits are in place, drilling and pre-feasibility development will be undertaken. Drill preparation work is in progress and further resource and step-out drilling as part of ongoing pre-feasibility studies is scheduled to begin in 2010.
In all, 119 targets were generated by systematic exploration in an area covering 12,110km², on 19,366 km² of mineral tenement contracts and applications in 2009. Three targets were drilled and 21 remain to be drill tested in Colombia.
AngloGold Ashanti initiated greenfield exploration in several areas of Canada in 2009, both on its own and in joint venture with two Canadian mineral exploration companies, Laurentian Goldfields and Commander Resources. Brief details of each project and its targets are given below.
Superior joint venture (AngloGold Ashanti/Laurentian Goldfields) – the Laurentian Goldfields Superior Province alliance is active in several areas of eastern Canada. Early stage fieldwork is being undertaken by Laurentian on regions considered prospective for gold mineralisation with drilling expected on new targets in 2010 or 2011.
Baffin Island joint venture (AngloGold Ashanti/Commander Resources) – AngloGold Ashanti is entering into a joint venture on Commander’s Baffin Island properties. Field work completed during 2009 returned encouraging results, on which drilling programmes will be planned for 2010.
AngloGold Ashanti initiated new greenfield exploration programmes in Brazil in 2009 and signed a joint venture agreement with a junior mineral exploration company, Horizonte Minerals, to explore two specific areas of the country.
Exploration activities were undertaken on the 7,443km² Concession 40 (AngloGold Ashanti 86.22%/OKIMO 13.78%) mineral claim that covers a significant portion of the Kilo greenstone belt, which remains largely unexplored by modern methods. This work comprised mainly regional mapping, soil sampling and data compilation while renegotiation of the joint venture agreement with the government of the DRC and OKIMO continued. It is anticipated that the revised joint venture agreement will be executed in early 2010, following which transfer of titles to the exploration licences to the joint venture company, Ashanti Goldfields Kilo, will be completed.
All drill holes from the Mongbwalu resource were re-logged and the resource remodelled in preparation for a pre-feasibility study based on an underground mining scenario. A detailed review of the historical data in the general Mongbwalu area was undertaken to assist with future exploration targeting.
In early 2009 assay results were received from all drilling completed at Mongbwalu Central and Adidi South in late 2008. The best intersections received are tabled below.
|Interval (m)||Grade (g/t Au)||From (m)|
Drilling recommenced in November and a total of 1,108m in 10 diamond holes was completed for metallurgical test work at the Mongbwalu Resource area. Field mapping continued along strike from the Mongbwalu Resource. Field work for the regional greenfields projects recommenced in November 2009 and consisted predominantly of soil sampling and trenching.
Field work was carried out at Lodjo, Camp 3, Petsi and Pluto North. A total of 1,878 soil samples, 195 rock chip and 452 trench and pit samples were collected for the year.
The dissolution of the joint venture (Zoloto Taigi joint venture) with Polymetal is in progress with divestment of the two exploration and four mining licences under way. This includes completion of the sale of Veduga, subject to conditions precedent.
AngloGold Ashanti expects that the Asacha Mine in Kamchatka, held by AIM listed Trans Siberian Gold in which AngloGold Ashanti has a 29.74% stake, will start production in the first quarter of 2011. A final round of financing for the last phase of construction (tailings facility, plant assembly, ore development) had almost been completed by the owners at the time of publication.
In Gabon, AngloGold Ashanti and its joint venture partners have collectively secured approximately 16,501km² of tenements in an under-explored region considered prospective for gold mineralisation. During 2009, a joint venture was entered into with Dome ventures over its Mevang and Ndjole licences, representing a combined area of some 4,000km².
AngloGold Ashanti holds the Ogooue prospection permit covering an area of 8,295km². The Mimongo and Koumaneyoung licences were acquired through acquisition of Amiga SARL from Swala Resources.
In June 2009, AngloGold Ashanti and Thani Investments, a privately held UAE-based company, entered into a strategic alliance to explore for and develop precious and base metal deposits in the Arabian Nubian Shield and other parts of the Middle East and North Africa.
The business development and project generation activities of the Thani Ashanti strategic alliance are conducted from Dubai. During 2009, work has focused on project generation and exploration over specific regions of the highly prospective Arabian Nubian Shield within Egypt, Eritrea and Saudi Arabia. Exploration conducted by the alliance has commenced on two exploration licences in Egypt.
In the Solomon Islands, AngloGold Ashanti has entered into two joint venture agreements with XDM Resources.
The Kele and Mase joint venture agreements cover an area of 738km² and to date in excess of 18 mineralised prospect areas have been identified. Five of these have returned significant widths of ore-grade mineralisation from trenches and drill holes. Exploration activities including field mapping, auger soil and rock chip sampling, spectral and petrological studies, have commenced in preparation for drilling in the first quarter of 2010.
In China, AngloGold Ashanti’s exploration activities are now limited to the cooperative joint venture over the Jinchanggou group of properties in the province of Gansu, located in western China. Limited trenching over a specific target and detailed infill soil sampling of the tenements was completed in late 2009. The results are currently under review. Elsewhere in China, AngloGold Ashanti continues to evaluate exploration opportunities.
At the Tropicana joint venture (AngloGold Ashanti 70%, Independence Group NL 30%), the start of the Tropicana feasibility study was approved by the joint venture partners in July 2009. Details on the study’s progress can be found in the following section.
The joint venture focused on exploration targets near the Tropicana-Havana deposits. During the year a total of 3,171 aircore holes were drilled for 127,562m, 281 reverse circulation holes for 36,888m and 46 diamond holes for 7,220m. Systematic surface auger sampling of 30,276 samples were collected and nearly 7,928 line kilometres of aeromagnetic and radiometric surveying, 256 line kilometres of IP surveying and 71 line kilometres of down-hole IP surveying was undertaken.
The best results for the year came from diamond drilling intercepts approximately 550m northeast of the proposed Tropicana pit, including 7m @ 2.1g/t Au from 141m and 14m @ 3.49g/t Au from 176m. Significantly, these intersections from the same hole may represent the faulted northern continuation of the Tropicana orebody. Encouraging results were also obtained to the south of the proposed Havana pit at the Havana South zone and Crouching Tiger prospects. In Havana South, significant intersections included 13m @ 2.37g/t gold from 317m and 21m @ 2.50g/t gold from 202m. Reverse circulation drilling at Crouching Tiger intersected 8m @ 2.83g/t gold from 134m.
In more regional exploration, significant aircore results were returned from Black Dragon, 30km northeast of the Tropicana–Havana resource, including 4m @ 0.6g/t gold from 40m. At Tumbleweed, 10km north of Tropicana, aircore drilling returned 8m @ 0.81g/t gold from 56m. These results confirm the anomalous zones identified by previous significant aircore intersections and extend the size potential of the targets. At Voodoo Child, 50km north of Tropicana, aircore drilling intersected 17m @ 2.25g/t gold from 3m. Infill aircore drilling and follow-up reverse circulation drilling are planned for these prospects in 2010.
In addition to the Tropicana joint venture area, which totals approximately 13,788km², AngloGold Ashanti holds 100% of a substantial land package (11,040km² in the Viking area, including 6,200km² of granted exploration licences). Viking is southwest of the Tropicana joint venture within the Albany-Fraser foreland tectonic setting that hosts the Tropicana deposit. Surface geochemical sampling continued throughout the year for a total of 10,390 samples and an airborne magneticradiometric survey was completed for 38,909 line kilometres.
The Tropicana joint venture and the Viking project extend over 600km of strike parallel to the Albany Fraser orogen, located at the boundary of the Yilgarn and Mawsom Cratons. The 5Moz Tropicana discovery, as well as numerous prospects identified by AngloGold Ashanti suggest that the Tropicana belt is emerging as a significant new gold province.
AngloGold Ashanti completed the purchase of the interests and rights of Anglo American Exploration Australia in the 830km² Saxby joint venture with Falcon Minerals Limited in northwest Queensland. Gravity (105 line kilometres), airborne magnetic-radiometric (7,436 line kilometres) and infill SQUID electromagnetic (37 line kilometres) surveying was completed to assist drill target definition.
AngloGold Ashanti Limited and the De Beers Group of Companies announced the formation of a joint venture to undertake initial exploration and to ultimately mine for gold and other minerals and metals from the ocean floor. This excludes diamonds, unless these occur together with other target minerals and metals. The joint venture’s activities will focus on marine deposits located in, or adjacent to, the area between the high water mark and the edge of the continental shelf on a worldwide basis.
The establishment of this joint venture will allow AngloGold Ashanti to take advantage of the opportunity of partnering with a world leader in the field of marine exploration and mining with a view to exploring and mining of the target minerals from deposits located on the continental shelf.
The joint venture has established a technical services company (AuruMar) to be jointly owned by AngloGold Ashanti and De Beers Marine. AngloGold Ashanti’s commitment under the agreement is to sole fund the joint venture and AuruMar until the completion of an initial exploration period of at least three consecutive sampling seasons as approved and budgeted for prior to 31 December 2012, or the date upon which AngloGold Ashanti has funded a total amount of $40m, whichever is achieved first. Upon conclusion of this period, AngloGold Ashanti will have earned equivalent interests to De Beers in all the sub-joint venture opportunities pursued under the joint venture. AngloGold Ashanti and De Beers will seek to secure majority interests for the joint venture in any sub-joint venture that involves a third party.
Initial work continues in New Zealand to complete the sonic drill rig and the launch and recovery system (LARS) as assets of AuruMar. Drilling scheduled to start in the first quarter of 2010. Initial drilling will target potential gold deposits off the west coast of the South Island, New Zealand.
The pre-feasibility study on the Tropicana Gold Project in Australia was completed during June 2009 and a decision was taken by AngloGold Ashanti and its joint venture partner to proceed with a full bankable study. AngloGold Ashanti is currently undertaking this study and seeking environmental approvals for open pit mining on behalf of the joint venture partner.
Tropicana, with a potentially greater than 5Moz gold Mineral Resource, represents a significant new discovery in a new gold district, about 300km east of Kalgoorlie. Should development of the project proceed, the mine is expected to produce an average of between 330,000oz and 410,000oz a year, at a total cash cost of between A$590/oz Au and A$710/oz Au, over a 10-year initial life. There is potential to increase the Mineral Resource and mine life through additional drilling at the nearby Havana South and other prospects.
The joint venture partners have agreed to report the Tropicana Gold Study’s Ore Reserve based on the outcomes of the pre-feasibility study. The Ore Reserve is based on the pre-feasibility study Measured, Indicated and Inferred Mineral Resource estimate of 75.3Mt grading 2.07g/t gold for 5.01Moz. The Ore Reserve is based on pit optimisation at an assumed $900/oz gold price and 0.85 A$/US$ exchange rate. The proved and probable Ore Reserve above the estimated break-even cut-off grade of 0.7g/t gold for oxide and transitional materials and 0.8g/t gold for fresh material on a 100% basis as at the 31 December 2009 is:
|Contained gold |
|Contained gold |
On a 70% attributable basis, the Ore Reserve totals 32Mt grading 2.3g/t gold for 2.3Moz. The mining inventory utilised for assessment in the pre-feasibility study includes additional Inferred Mineral Resource within the open pit design for Tropicana and Havana. Consistent with internationally recognised codes for the reporting of the Mineral Resource and Ore Reserve, the Inferred Mineral Resource are not part of the Ore Reserve.
Drilling and an update of the Mineral Resource model as part of the feasibility study has been completed and the estimate is currently being internally and independently reviewed and audited. A close-spaced drilling programme was completed within the Havana Mineral Resource to simulate grade control drilling. Results from this drilling confirm the Mineral Resource interpretation and the continuity of mineralisation. The data will be further analysed to validate the Mineral Resource model and to optimise grade control and mining selectivity.
Work on updating the pit designs, mining schedules and reserve for the feasibility study has commenced. Tendering for contract mining is in progress, with owner mining costs to be updated.
A comprehensive metallurgical test work programme for the feasibility study has been substantially completed. Results confirm the processing flowsheet selected from the pre-feasibility study of primary and secondary crushing, high pressure grinding rolls followed by conventional carbon-in-leach. A number of engineering studies have been undertaken to optimise the plant, operating and capital costs, and operating performance. The major aspects of the plant design and engineering will occur in early 2010.
Geotechnical studies for the mine access road and tailings storage facility are in progress and will be utilised as inputs for refining designs and developing feasibility-level cost estimates.
The eight-week public review period for the Tropicana Gold Project environmental impact assessment closed in late November 2009 with a limited number of submissions received. The Tropicana joint venture is currently consulting with the organisations that made submissions and is developing a formal response to the submissions, which will be provided to the office of the Environmental Protection Authority. The Environmental Protection Authority will provide a recommendation on the project approval and conditions to the Western Australia Minister for the Environment. The approval and conditions are subject to public appeal.
Brownfields exploration, was undertaken around the globe at most current operations, with the most success having been achieved in South Africa, Mali, Guinea and the United States. The brownfields exploration programme for 2009 was aimed at replacing ounces at current operations and successfully added a total of 3.5Moz to the company Mineral Resource.
At Cerro Vanguardia, the exploration programme continued with Mineral Resource delineation drilling and reconnaissance drilling. Significant drilling was completed on underground targets and a full underground study is currently under way. In the El Volcan project area, initial exploration started with sampling, mapping and geological reconnaissance work completed. A detailed aeromagnetic survey of the sector started in the last quarter, with some interesting structural trends identified. The survey was delayed by an unfortunate helicopter incident which damaged the probe.
At the Sunrise Dam, exploration focused on infill drilling within the existing Mega Pit and continuing to extend the underground Mineral Resource. The in-pit drilling confirmed that mineralisation beneath the Sunrise shear and Midway shear zones continues up-dip and may provide the opportunity for an internal cutback on the eastern side of the Mega Pit. Further underground drilling has identified extensions to the high-grade Cosmo, Astro, Dolly and GQ lodes. Additional investigations on the extensions to high-grade gold mineralisation, that lie open below 1km vertical, continues.
In addition, exploration for satellite pits in the surrounding district continued at Golden Delicious, the paleochannel, Neville and Wilga (Chalice 100%; AngloGold Ashanti earning 75%) prospects.
At the Córrego do S?tio Sulphide Project, drilling continued with 6,505m drilled from surface and 15,682m drilled from underground. The drilling was aimed at defining and converting the three main ore zones. A total of 4,718m of underground development was completed. For extensions of Córrego do S?tio into São Bento, a further 23,426m of surface drilling was completed. At the Lamego project, 19,838m of surface drilling and 3,000m underground drilling was completed. A total of 4,368m of underground development was completed.
At Serra Grande, the main targets for 2009 were Pequizão, Fiuca, Cajuerio and Palmeiras. The Devidrill system, which allows many deflections to be drilled off a single hole without the use of steel wedges, was successfully tested. The use of this system is expected to save drilling metres and reduce the environmental damage by restricting drill site clearance.
At Obuasi, drilling for the Deeps project below 50 level continued with the areas below KMS and Adansi Shafts being targeted from 50 level. This drilling was stopped in the third quarter as the results of flooding. The drill sites on 50 level are still to be rehabilitated. Active exploration continued above 50 level.
At Iduapriem, drilling for the year consisted of Mineral Resource Conversion drilling at Ajopa and it was completed in the first quarter.
At Siguiri in Guinea, exploration focused on in-fill drilling within the area of the central pits. During the year all the central deposits were built into a combined geological and grade model and exploration was initiated to prove up potential economic extensions. This drilling took place adjacent to and between the Bidini, Sanu-Tinti, Sorofe, Tubani, Kalamagna, Kozan and Kami pits.
Diamond drilling continued to investigate the fresh rock potential below the Kosise, Bidini, Sanu Tinti and Kami pits.
Extension drilling to the Sintroko Project, based on anomalous soil sampling and previous drilling, was done to the north, east and west of the main deposit. An additional 500m of Inferred Mineral Resource was defined.
Geochemical soil sampling continued in Block 1 to the north and north-east of current mining operations and east of the Sintroko. The Komatigiuya target, a 1,000m soil anomaly, was discovered by the sampling and represents a significant new discovery.
IP Geophysical equipment arrived on site and a test self-potential survey over Sintroko South was completed. Results are promising with IP anomalies co-incident with known mineralisation. Future surveys will include Toubani and the rest of the Sintroko area.
At Morila, exploration stopped in the second quarter after follow-up drilling based on the revised geological model proved unsuccessful.
At Sadiola, exploration activity focused on drilling the area around the FE4 pit where mineralisation was extended along strike and into the gap between FE3 and FE4. The Sadiola Deeps infill drilling recommenced in December.
A high-resolution aeromagnetic and radiometric survey was completed over the Sadiola and Yatela mining lease areas.
At Yatela, an intensive programme aimed at extending the mining into 2010 continued during the year. Significant success was achieved along the edges of the Yatela Main pit, Yatela North and Alamoutala. Drilling will continue in 2010.
At Navachab, Mineral Resource conversion drilling was completed at Gecko. Further Mineral Resource conversion and extension drilling was completed around the Main pit, the hanging wall sheeted vein system and North Pit 2 footwall veins.
Regional exploration continued with drilling in the Gecko Valley, which is targeted at joining the Central and Southern areas. Drilling was also started on the Klipspringer, Steenbok and Starling targets. A gradient IP survey was completed over the Anomaly 16 prospect. The results indicate the potential for significant sulphide mineralisation.
In South Africa, surface drilling continued in the Project Zaaiplaats area. MMB5 continued drilling for the entire year. Deflection 7 is now being drilled to intersect the Vaal Reef. MZA9 continued drilling and is currently drilling deflection 23. The first reef intersection is now expected in the second quarter of 2010. The long deflection from MGR6 continued drilling and the hole is currently at a depth of 2,397m. The Vaal Reef is expected to be intersected in the third quarter of 2010. Progress on MGR8 was slowed by poor ground conditions. The hole is currently at 3,020m and a reef intersection is anticipated in the first quarter of 2010.
In the Western Ultra Deep Levels area, UD51 started drilling in the first quarter and intersected a partly artesian fracture system which has significantly reduced the advance. The hole is currently at a depth of 2,796m and a Ventersdorp Contact Reef intersection is expected in the second quarter of 2010.
At Geita, for the first two quarters extension and infill drilling continued at Star and Comet, Chipaka and Kalondwa Hill. Initial aircore drilling was conducted over Matandani NW and Nyamalembo. Regional target generation work was completed and 41 targets identified for follow up.
In the third quarter, the focus of the exploration activities was revised and concentrated on three activities: ground geophysical surveys, a core re-logging programme of the Central Thrust Ramp ore zones and the infill drilling programme for Nyankanga Cut 7 and Geita Hill. The latter programme was brought forward from 2010, in order to bring the corresponding Mineral Resource to Indicated and to reduce risk in the plan. The infill drilling programme at Nyankanga Cut 7 was completed in December. A total of 16,727m was drilled. Logging and sampling will be completed in first quarter of 2010.
At Cripple Creek & Victor, extension drilling at Squaw Gulch and North Cresson continued during the year.
Drilling and studies continued to quantify the potential of the high grade Mineral Resource particularly in the east of the Cresson deposit. Metallurgical testing of high grade material is underway and further metallurgical test drilling has been planned.