One of the higest-grade gold projects in Australia

Overview

Northwest’s Blue Spec Shear Project, located less than 2 hours drive from the Pilbara hub of Newman, is one of the highest-grade gold projects in Australia. The high grade underground resources of the Blue Spec Shear project total approximately 190,000 oz gold at an average undiluted grade exceeding 43 g/t Au.

Project Area

The Blue Spec Shear is located in the Nullagine goldfield and extends east-west over a length of some 20kms north-east of the township of Nullagine. The mineralization of the shear is typically quartz reef development containing very high-grade gold and antimony. The recently discovered Red Ribbon Shear lies approximately 1km to the north of, and parallel to, the Blue Spec Shear and exhibits the same key characteristics as the Blue Spec Shear. The Blue Spec Shear Project represents the dominant tenement position on both the Blue Spec and Red Ribbon Shears.

Deposits

Northwest has two established high-grade underground deposits within the project area. These are the Blue Spec and the Golden Spec deposits which are located at the western end of the Blue Spec Shear. In addition, a very high grade shoot has also been defined at Green Spec, less than 3kms east of Blue Spec.

Each of these deposits exhibit the same geological features, including:

  • very high-grade gold grades which increase significantly with depth
  • steeply dipping vein hosted mineralisation (generally 2-3m wide)
  • excellent depth continuity
  • distinct and consistent metal association
  • deposits hosted in localised structural settings
  • recognizable geological footprint, alteration and fluid-chemical characteristics

The Blue Spec and Golden Spec deposits were discovered through outcropping mineralisation. Northwest’s exploration of the Green Spec deposit has recently led to the recognition of “mineralisation halos” comprising low grade gold with the presence of antimony and trace levels of arsenic which appear to be the near-surface expression of high-grade mineralisation which has not outcropped on the shear.

This halo feature goes some way to explaining why additional high grade gold-antimony deposits have not been discovered in the past as the low grade gold/antimony/arsenic may have hidden the high grade gold-antimony mineralisation below surface.

Northwest is using the recognition of this halo feature, together with advanced alteration and fluid-chemical models to identify numerous new targets along both the Blue Spec and Red Ribbon Shears.

Exciting Exploration Potential

The Blue Spec Shear, outside the Blue Spec and Golden Spec mining areas, has received almost no modern exploration. This absence of modern exploration, together with the presence of deposits at both the western and eastern ends of the Blue Spec Shear, highlights the potential of the Blue Spec Shear and the Red Ribbon Shear which was discovered by Northwest in mid-2006 to host further high-grade gold deposits.

Since listing in December 2004, Northwest completed a total of 70,000m of RC and diamond drilling, collected over 9,000 surface samples and recorded 20,000 mapping points at its Nullagine Goldfield projects. As a result of accumulating this data Northwest now has an unparalleled understanding of the geology of the Nullagine Goldfield.

This has enabled our exploration team to develop a predictive targeting model for the Blue Spec Shear to generate numerous high grade gold targets on the Blue Spec Shear and the new Red Ribbon Shear and to recognise for the first time the Blue Spec Shear gold project’s potential to host over 1 million ounces in high grade gold deposits.

Infrastructure and Treatment Plant

Significant existing exploration and mining infrastructure is located within the Blue Spec Shear Project, adjacent to the Blue Spec deposit, including:

  • established shafts, declines and access drives
  • a CIP treatment plant (currently configured for a throughput of around 40,000 tpa but with existing crushing units with a capacity of around 100,000 tpa)
  • access to sufficient water for operations
  • tailings dam
  • fully equipped mining camp

The existing infrastructure will significantly reduce the capital expenditure and time required to bring high-grade gold deposits identified along the extent of the Blue Spec and Red Ribbon Shears into production.

 

Page last updated: 09.08.2007