The quarter brought to an end another very busy year in exploration and put the company in a very good position to continue its strategy of development through exploration successes and organic growth. Randgold hasa quality groundholding of 14 133km2 across some of the most prospective gold belts in Africa, from the Democratic Republic of Congo in the east to Senegal in the west, and a well-balanced resource triangle containing 302 targets, from the regional level to reserve definition.
During the current quarter the company had 12 rigs drilling on five different project sites in four countries: Gounkoto (Mali), Loulo satellites (Mali), Massawa satellites (Senegal), Tongon (Côte d’Ivoire) and Kibali (DRC).
In the fourth quarter a total of six holes were completed in the jog zone totalling 3 166 metres: GKDH354, GKDH353, GKDH352, GKDH350, GKDH359 and GKDH351. These holes were drilled to test the margins of the high grade mineralisation in the jog zone where the block model was projected but where there is very wide drill spacing. They have confirmed the geological model and resource potential in the jog zone. Results received during the quarter include: GKDH352 - MZ2 18.2 metres at 23.16g/t from 532.80 metres; and MZ3 15.50 metres at 6.07g/t from 558.10 metres. This programme is still in progress and will be completed and reported in the first quarter of 2012.
The RC rig returned to Faraba this quarter, to complete a programme of 32 holes for 3 495 metres drilled where the latest resource estimate of 540 000 at 2.62g/t falls within the US$1 200 pit shell. Drilling has confirmed the continuity of the mineralisation along the orebody at 50 metre spacing. All the holes intersected strong silicification, weak carbonate and weak albite alteration, with an average grade within the original block model of 42 metres at 1.8g/t. A new footwall zone has also been intersected, outside the current resource. This zone returned intersections of FADH177 - 91 metres at 1.53g/t; and FADH04 - 39 metres at 1.3g/t, highlighting further upside potential.
A total of 22 holes was completed at P64 for 1 867 metres drilled over two different mineralised zones. This includes the Main Zone at P64 and the Eastern Zone in the greywacke ridge. P64 is a complex target and has been parked for a number of years due to the work on the Gounkoto deposit. The purpose of this programme is to produce new data from the target in order to improve our models and understanding. The strike length of both structures has been extended by this programme and the holes have confirmed the model.
Gounkoto regional exploration
In the current quarter, three step out holes totalling 1 141 metres were drilled to the south and to the north of the existing mineralisation at Toronto South, at 200 metres vertical depth. These holes tested the structure at 200 metres spacing over a total strike of 1.24 kilometres. The holes all intersected the altered Toronto South structure. However, mineralisation was found to be virtually absent and the alteration much weaker than what had been seen in holes FRDH012 - 16 metres at 2.41g/t and FRDH018 - 24 metres at 2.17g/t and 19.6 metres at 3.36g/t. Interpretations suggest a blind potential at Toronto South as these holes may be grazing the top of a deeper system within the larger Faraba trend.
33 diamond holes were drilled on the two principal structures of the Loulo 3 target to infill the area between the US$1 000 and US$1 300 pit shells, in order to upgrade the 275 000 ounces at 2.96g/t of inferred resources to measured and indicated, permitting a full push-back of the Loulo 3 pit. This infill drilling programme confirmed the model and the weighted average of the holes returned 8 metres at 2.7g/t.
At P125-L3, a programme of RC drilling has confirmed a geological potential of 27 000 ounces at 2.7g/t to a depth of 70 metres, over a 450 metres strike. Within this zone, a shallow zone of higher grade mineralisation grading 3.64g/t, down to 20 vertical metres and over 300 metres strike, has been confirmed.
Randgold completed a preliminary analysis of the resource inventory outside of the current LOM budget. Initial studies focused on the heap leach potential of low grade material. However, this proved not to be viable due to low recoveries. Randgold has since concentrated on conventional CIL which has returned positive results with recoveries of approximately 90%. Randgold is now progressing with a scoping on resources of 63.5Mt at 3.46g/t for 7 million ounces.
The Loulo District is highly prospective and contains three world-class orebodies as well as a host of satellite deposits. Randgold believes that potential still exists throughout the region for the discovery of further multi-million ounce deposits, either at surface or at depth, which may well be blind and not outcropping at surface.
A combination of two models is currently driving Randgold’s interpretations. Firstly, that a major transcrustal structure which bisects the orebodies of Gounkoto and Yalea transgresses the area. Secondly, a fold belt which may be related to movement on this structure runs approximately along the same trend and hosts a good deal of the known mineralisation on the Loulo permit. Folded targets which lie within this belt include Baquata, Gounkoto, P64, Kolya, P129 and Gara.
Refolded folds in the areas, where these two phenomena combine, are thought to be the most prospective and conceptual targets and include blind saddle reef mineralisation in fold hinges and mineralised shears on fold limbs and axial planes. The albitites on the Bambadji permit also sit in a tight, upright antiform and the possibility that they are the distal alteration halo of a deeper, zonational, gold-bearing, hydrothermal system is being considered. This is a work in progress and these targets will be generated in the first quarter of 2012.
At Yalea, a total of 16 holes for 1 932 metres were drilled to investigate two targets: the low grade block south of the Yalea North plunge, and the gaps within the high grade purple patch. The drilling south of the Yalea North plunge confirmed good continuity of grade above the resource model: YUDH231 - 4.96 metres at 6.45g/t; YUDH232 - 3 metres at 5.38g/t; and YUDH233 - 3 metres at 5.14g/tcompared to 12.2 metres at 3.46g/t.
The drilling which targeted the purple patch returned intersections similar to the block model prediction. The weighted average actual grade for these holes was 18.7 metres at 9.12g/t, which is in line with the block model. Intersections include: YUDH 217 - 22.8 metres at 12.05g/t; and YUDH 218 -21 metres at 11.52g/t.
At Gara, a total of 24 holes for 1 920 metres was drilled from 40L and 65L to close the gaps within the resource model around the southern portion of the fold nose. Results confirmed the folded nature of the deposit and grade of the resource model.
After successfully negotiating and signing, the Nimissila JV with the Djiguiya Group on a groundholding to the immediate south of Bougouni in the centre of the Mali South area, a regional soil sampling programme, has been completed. The results identify seven regional anomalies with gold values above 20ppb. Multi-element data is pending and will be integrated with the gold results to prioritise areas for follow-up geochemistry in 2012.
Geologically the area is underlain by biotite rich sediments which are often shallow-dipping with numerous small stocks and bosses of granodiorite.
In previous quarters it was reported that the MTZ had been prioritised over other targets and structures within the Mako belt, and that this structure was the principal focus of our work around Massawa. This quarter, a RAB drilling programme was initiated over six new targets along the MTZ: four targets in the Samina region, as well as the Kaldou Kaya target and the Saraba target. This drilling focused on the major belt margin contact between the volcaniclastics and the sediments (where Massawa and Delya are hosted) particularly where it coincides with cross-cutting structures and soil anomalies. Drilling has so far confirmed Randgold’s interpretations and the target structure which hosts the Massawa and Delya deposits. The work also confirms that this structure is a major fluid pathway with strong shearing, alteration and anomalism. However, the grades intersected so far are only weakly anomalous and these results will be used to vector into more prospective areas along the structure, particularly where second order structures are interpreted to be present.
The RAB programme and resource triangle were subject to review in order to find a non-refractory deposit for the Massawa project. Targets scheduled for work in early 2012 include East Mandinka, a large geochemical anomaly along the northern part of the MTZ,and KB in the Mako Belt. Other targets being reviewed within the belt are Nouma, Missira, Soma, Mariama, KC South and Rheina.
A programme of RC drilling was completed at Seydou southern zone and returned multiple mineralised lodes with results including: SSRC023 - 32 metres at 2.36g/t from 76 metres including 13 metres at 4.89g/t from 79 metres and 3 metres at 7.96g/t from 84 metres; and SSRC024 - 3 metres at 3.96g/t from 18 metres. Drilling also confirmed a new western zone of mineralisation: SRC010 -28 metres at 1.80g/t.
Data integration and geological modelling has led to the potential for 483 084 ounces at 1.48g/t from the satellite targets (Sekala, Tongon West, Seydou and Jubula) within a 15 kilometre radius of the Tongon plant.
Throughout the quarter, work focused on the Diaouala permit to the north of Nielle. Afirst phase of air core drilling was completed, within the 25 kilometre long Kokoriko-Satolo structural corridor, to test the Dabokiri target. This reconnaissance drilling targeted the lithological contacts, dilational zones and belt margin structures that coincide with soil anomalies. A total of 173 holes for 6 265 metres was completed. The lithologies intersected include sheared and quartz veined andesite, argillite, granite/granodiorite and diorite. Common alteration phases are: limonite, silica, sericite and biotite. Although initial results are only anomalous in gold 0.1 to 0.8g/t, the objective at this stage is to identify a continuous zone of anomalism as a vector to sites of economic mineralisation for follow-up work.
While integrating drill results from the aircore programme, work will continue on the unexplored targets identified within the permit. These targets lie on the continuation of structures which host the Nogbele, Stinger and Ouahiri deposits of Gryphon Minerals Banfora project in Burkina Faso.
Reconnaissance work has also recommenced within other permits heldin northern Côte d’Ivoire including Boundiali.
DEMOCRATIC REPUBLIC OF CONGO
The geological model identifies the potential lateral continuation of the 9000 lode and possible link between KCD and Gorumbwa. Two previous stratigraphic holes drilled between KCD and Gorumbwa returned encouraging results: DDD456 - 7.5 metres at 1.64g/t from 504 metres, 7.75 metres at 4.34g/t including 2.2 metres at 13.25g/t from 529 metres, and 3.8 metres at 1.16g/t from 549.7 metres; and DDD457 - 4 metres at 4.75g/t from 450 metres and 2 metres at 4.56g/t from 790 metres,which indicated the possibility of extending the 9000 lode mineralisation towards the Gorumbwa deposit.
A programme of five diamond holes for 3 980 metres has been proposed, not only to test this link but also to test the extension of the 3000 lodes, especially at Durba Hill, where previously access was not possible due to the presence of infrastructure owned by SOKIMO. The programme will initially test a one kilometre strike-length with holes spaced approximately 200 metres apart. These holes will be drilled in the first quarter of 2012.
At Zambula, adit sampling returned 5.1 metres at 4.27g/t. A first reconnaissance hole was completed by year end and the core intersected a package of volcanoiclastics followed by magnetite and chert banded horizons in line with the geological model. The cherty bands display sericite bleaching and fine disseminated pyrite mineralisation within the shear fabric as well as in the magnetite at about 1% over an accumulated length of about 20 metres, with localised trace arsenopyrite. The hangingwall (eastern) cut-off is marked by a strong graphitic shear also containing massive pyrite mineralisation. Gold assay results from this hole returned a weakly anomalous intersection of 47 metres at 0.2g/t. The aim is tocomplete further reconnaissance work including drilling along the entire 5 kilometre structure.