JOHANNESBURG (miningweekly.com) – ASX-listed Orion Gold has started a major new phase of drilling at its Prieska zinc-copper project, in the Northern Cape, where the first two holes of the programme are designed to test mineralisation in the north-west target area.

The programme will further evaluate the main deep sulphide target below the historical mine, which is expected to form the cornerstone of the company’s development strategy.

The deep sulphide mineralisation is the down-dip extension to mineralisation mined in the historical Prieska copper (PC) mine, which has been previously tested by extensive historical drilling.

The previous operator of the historical PC mine did not routinely assay for precious metals and, therefore, no assays for gold or silver are available. Drilling is now aimed at statistically validating the historical drilling results so that reliance may be placed on that data for resource estimation.

The initial drilling will also provide technical information that will allow Orion to plan and complete a drill programme aimed at testing the mineralised zone previously tested with drilling on a new, superimposed 45 m x 45 m grid spacing, which correlates to 89 historical intersections.

Of these, a number will be twin holes validating historical drilling results.

Historical information shows that Anglovaal, the previous owner of the PC mine, used drilling at various spacings for mine planning purposes. While this drilling was completed well before the time of modern resource/reserve classifications, it nonetheless serves as a valuable guide owing to the success of the historical mining operation over a 15-year production period.

The drilling programme will take advantage of advances in drilling technology and expertise, with directional drilling to be used to achieve multiple deflections from a single mother hole, thereby reducing the total amount of drilling required.