Oct 22 2013
Nevsun Resources Ltd. is pleased to announce further diamond drill results from resource definition drilling at the Northwest Zone poly-metallic massive sulphide deposit, located 2 kilometers from the Bisha processing plant within the Bisha mining license.
HIGHLIGHTS
- Northwest Zone still open to south and north
- Four down dip step-out holes demonstrate that the mineralized system continues at depth
- Additional parallel zone identified but limited drilling to date
- Maiden mineral resource estimate in early 2014
Selected New High Grade Results Include:
- Hole NWDD129 - 14.1 m* @ 1.06 % Cu and 3.89% Zn from 111.9 m to 126.0 m (MS)*
- Hole NWDD130 - 14.0 m @ 17.2 g/t Au and 49.0 g/t Ag from 101.0 m to 115.0 m (S)
- Hole NWDD131 - 18.5 m @ 2.11 % Cu and 13.5 g/t Ag from 93.5 m to 112.0 m (M-S)
- Hole NWDD160 - 3.7 m @ 2.21% Cu and 3.3 g/t Au and 12.1 g/t Ag from 216.0 m to 219.7 m (M-S)
- Hole NWDD173 - 20.5 m @ 1.40 % Cu and 17.3 g/t Ag from 77.5 m to 98.0 m (M-S)
- Hole NWDD185 - 5.2 m @ 5.2 g/t Au and 13.9 g/t Ag from 52.5 m to 57.7 m (O)
- Hole NWDD187 - 14.2 m @ 1.21 % Cu and 2.06 % Zn from 110.6 m to 124.8 m (M-S)
- Hole NWDD189 - 14.5 m @ 3.2 g/t Au from 39.0 m to 53.5 m (O)
- Hole NWDD195 - 5.2 m @ 0.60 % Cu and 3.64 % Zn and 27.5 g/t Au and 174.6 g/t Ag (M-S) from 105.8 m to 111.0 m (M-S)
*Notes: Mineralization Types: M = Massive Sulphide; M-S = Massive and Stringer Sulphide; S = Stringer Sulphides; O = Oxidized Material; D = Dyke. Intervals given are drilled metres. True widths are generally 70 to 90% of drilled length depending on hole and mineralisation orientation.
Selected holes are shown in the deposit map below.
Bisha Mining Share Company (BMSC) completed the resource definition and expansion drilling program totaling 216 holes at the Northwest Zone in May 2013 and drilled a further 4 holes in July and August 2013. A total of 18,892 meters of drilling has been completed at the Northwest Zone in 2013. Assay results received to-date from holes NWDD118 - NWDD198 that were completed in 2013 are included at the end of the release. Prior drilling results were released on May 23, 2013. Remaining results will be released later in 2013.
Work on the maiden resource estimate is in progress and the results are expected to be included in a BMSC mineral resource and reserve update in early 2014. The estimate will include Bisha Main and Harena resource and reserve updates and Hambok and the Northwest Zone maiden resources.
Map: Northwest Drilling Results
Mineralization at the Northwest Zone occurs in a series of massive sulphide lenses hosted within altered felsic volcanic rocks containing abundant copper and zinc-rich stringer sulphide mineralization. Gold and silver are occasional highly enriched in these stringer zones and are often associated with later dykes. Some of the massive sulphides have been exposed to weathering at surface creating oxide zones that are locally enriched in gold. Beneath these areas, some supergene copper mineralization may also be present. Core recovery is often poor in the oxide zones as unconsolidated material is easily washed away and not recovered during the diamond drilling process. Further testing of these areas by reverse circulation drilling will be completed in due course.
The mineralized system at the Northwest Zone is extensive and resource expansion opportunities remain to the north, south and at depth. In July, four holes were drilled beneath the central and northern portions of the deposit. This drilling demonstrated that the mineralized system continues to depth and appears to be thickening to the south. Assays are still outstanding, but further drilling to the south is warranted. In addition, to the east there is a parallel zone of massive sulphide that is only defined by limited drilling.
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 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. This drill program has now been completed and has successfully extended the mineralization an additional 400 meters in strike length.
Quality Assurance
A Quality Assurance/Quality Control program was part of the sampling program for the Northwest Zone work. This program includes a chain of custody whereby drill core samples are initially crushed and subsampled at the Bisha Mine preparation facilities before being transported to Asmara, sealed, and sent on to the laboratories of ALS Limited in Vancouver. ALS is accredited by the Standards Council of Canada. Multi-element analysis is completed using ICP-AES methods; gold is analyzed by fire assay with AAS finish. Certified reference material (standards), duplicates and blank samples are systematically inserted into the flow of core samples and results analyzed on a batch by batch basis.
Hole collars are surveyed using differential GPS; down hole survey was originally completed using the Reflex EZ shot method, now superseded with downhole gyro methods.
Mr. Paul Gribble C.Eng., FIMMM, BMSC's Chief Resource Geologist has been overseeing the drilling and resource work at the Northwest Zone and is a Qualified Person as defined by NI 43-101. Mr. Gribble has reviewed the technical content of this press release and approved its dissemination.