Mine district exploration

Mine district exploration takes place around the Company’s suite of operations and development sites to find opportunities to extend mine life.

Mine district exploration projects are as follows:

2011 program highlights

Sepon

Oxide gold exploration programs at Sepon continued to discover small, near-surface, low-grade deposits. These included Vang Ngang East, Vang Ngang South, Thongpiang West and Red Hill, which are now at the resource definition stage. A number of other prospects have been defined and are in earlier stages of evaluation. On current projection, the life of the Sepon oxide plant is forecast to continue until 2013.

Primary gold exploration programs have considerably expanded the extent of the mineralised system at Discovery Main/Dao Leuk, increasing the total Resource for primary gold at Sepon to 45 million tonnes at 2.2g/t gold for 3.2 million ounces (Indicated and Inferred). This represents a 47% increase in total ounces from 2010. A number of other prospects returned very encouraging results in the first phase of drilling, including Phavat North (3m @ 26.5g/t gold), Phavat Main (13m @ 5.8g/t gold) and Vang Ngang South (21m @ 4.7g/t gold). During 2011, oxide copper exploration programs were limited as the focus was on gold exploration, but extensions to mineralisation around Thengkham East were defined.

A number of primary copper targets were tested. Encouraging results included Thengkham East (123m @ 0.64% copper), Thengkham South (21.5m @ 1.2% copper), Phavat West (9.5m @ 2.0% copper, 1.2g/t gold) and Khanong South (13m @ 2.1% copper). These results indicate good potential to increase the primary copper skarn-related resource at grades around 1% copper equivalent.

Sepon near-mine exploration.

Century

Reviews at Century concluded that the potential to discover additional Century-style mineralisation at greater than 10% zinc is effectively tested. The Mine Operations team will resume a number of near-mine initiatives for identification of additional feed for the processing plant from vein breccia-style occurrences at Silver King, Watson’s Lode and the Termite Range corridor. In addition, the viability of utilising Century infrastructure to exploit the phosphate deposits that occur on the Company’s tenements continues to be studied.

Golden Grove

Following significant exploration success in 2010 at Gossan Valley and Felix, exploration during 2011 focused on resource definition drilling totalling more than 70,000 metres. As at December 2011, the Gossan Valley and Felix Resource stood at 1.5 million tonnes of zinc ore at 7.9% zinc, 10g/t silver and 0.9g/t gold; plus 1.3 million tonnes copper ore at 2.3% copper, 14g/t silver and 0.3g/t gold. Drilling was also conducted at the Flying Hi and Cullens prospects. At Flying Hi, broad zones of low-grade copper with some narrow higher grade intervals, including oxide copper and chalcocite, were encountered.

Rosebery

Deep drilling on the Rosebery mine lease under the Aegis project confirmed the shallow northerly plunge of the Rosebery mineral system into the newly acquired Lake Rosebery tenement. Significant progress was made during 2011 building and validating the Rosebery exploration
database to generate a 3D regional geological interpretation of the 25-kilometre strike length Rosebery host horizon. This model will be instrumental in ongoing targeting for resource extensions.

Avebury

The exploration strategy at Avebury has been driven by the need to define all discovery options that have potential to transform the project economics of the Avebury nickel deposit. The single target defined by the 2010 versatile time-domain electro-magnetic (VTEM) airborne geophysical survey was drilled in 2011. The hole intersected small (1–6m) slivers/dykes of altered ultramafic with low levels of nickel.

Izok Corridor project

At Izok Lake, a 15,000-metre drilling program successfully traced the Izok host horizon 750 metres down dip and along strike to the south of the deposit, intersecting sporadic thin low-grade mineralisation. Further drilling in this area is scheduled in the first quarter 2012 to definitively test for near-resource massive sulphide extensions.

At High Lake East, a 20-hole drilling program over 7,000 metres confirmed this prospect as a new discovery representing a third significant volcanic massive sulphide (VMS) mineralised system with high-grade zinc and copper massive sulphide lenses that appear to be increasing in width at depth. Best intersections include: 21m @ 11% zinc, 0.6% copper from 143m downhole, and in another hole 33m at 7.5% zinc, 2.1% copper from 633m, although true thicknesses are likely to be 60% of these actual intersections. Drilling and downhole electro-magnetic (EM) geophysical survey data suggests that the best mineralisation occurs as two steeply plunging shoots within a broader mineralised horizon.

Mincenco bauxite project

A resource drilling program was initiated in the fourth quarter 2011 on the Mincenco bauxite project in Jamaica. The objective of the drilling is to validate the historical resource database and ascertain what work is required to define a Measured Resource target circa 20 million tonnes (dry metric), 20 million tonnes Indicated and 100 million tonnes Inferred Resource in accordance with JORC standards.

• Interactive Map
• Mining operations
  • Century
  • Golden Grove
  • Kinsevere
  • Rosebery
  • Sepon
• Other Operations
  • Avebury
  • Mawson West
• Development projects
  • Dugald River
  • Izok Corridor
  • Mutoshi project
• Exploration
  • Mine district exploration
  • New discovery programs
  • Project generation
• Locations