May 27 2013
Nevsun Resources Ltd. is pleased to announce diamond drill results from resource definition drilling at the Northwest Zone, located 1.2 km from the Bisha processing plant.
Bisha Mining Share Company (BMSC) has now completed the initial resource definition drilling program at its Northwest Zone located 1.2 km from its operating Bisha Mine. In 2013, 15,890 meters of drilling was completed at the Northwest Zone. This is in addition to 4,325 meters completed in 2011 and 13,520 meters completed in 2012. The system remains open to the north, south and at depth but drilling efforts have now shifted to the Hambok deposit to support 2013 work requirements on the Mogoraib exploration license.
Complete assay results received to-date from 2011, 2012 and 2013 drilling are included at the end of the release. Results from holes NWDD-129 - NWDD-201 are still outstanding but will be included in the maiden Mineral Resource Estimate.
Mineralization at the Northwest Zone is complex with a series of massive sulphide lenses hosted within altered felsic volcanic rocks. Both the footwall and hangingwall contain copper and zinc-rich stringer sulphide mineralization. Synvolcanic faulting and slumping associated with rhyolite cryptodomes and post volcanic faulting associated with regional deformation add complexity. The massive sulphides have been exposed to weathering at surface, oxide zones have been developed that are locally enriched in gold and beneath these areas, supergene copper mineralization may also be present. Core recovery is often poor in these zones as unconsolidated material is easily washed away and not recovered during the diamond drilling process. A program of RC drilling will be completed in these areas to better define the oxide gold potential.
The mineralized system at the Northwest Zone is extensive and resource expansion opportunities remain to the north, south and at depth. Further drilling is planned for the second half of 2013 to assess this potential. In addition, to the east there is a parallel zone of massive sulphide that is only defined by limited drilling. Further drilling on this new zone is also anticipated later in 2013.
Work for a maiden Mineral Resource Estimate at the Northwest Zone is in progress. This work in conjunction with an economic assessment of the impact of the Northwest Zone is expected to be included in a Mineral Resource and Mineral Reserve estimate update for the entire BMSC operation anticipated for early 2014.
The Northwest Zone was discovered in 2003 by the diamond drilling of an airborne EM anomaly and follow-up ground geophysics, soil sampling and drilling from 2004 to 2006 defined a 600 meter long zone of massive and stringer sulphide mineralization. Further work was deferred from 2007 to 2010 while the Bisha deposit was being prepared for mining. A program of in-fill drilling was started in late 2011 designed to fully delineate the open-pit potential of this Zone. This drill program has now been completed.