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probable ore blocks above the Hill 50 No. 5
<br />Level where access has been regained.
<br />Ore reserve increases were slightly offset by
<br />tonnage reductions underground at Morning
<br />Star and WaterTank Hill.
<br />The reduction in underground reserve
<br />grade Is due largely to additions at lower
<br />than average grade at Mars and Hill 50.
<br />A total of 25,690 metres (18,890 metres in
<br />1984185) of exploratory and development
<br />drilling was completed during the year.
<br />Underground drilling concentrated on the
<br />Hill 50, Mars and Morning Star areas, whilst
<br />surface drilling was mainly at Morning Star
<br />and Evening Star, with lesser amounts ai
<br />Nathan, Bullocks and Edwards Carson.
<br />Stowell Joint Venture
<br />(75.2% owned: 50% through Great Boulder Holdings
<br />L[d, and 75.2% through Central Norseman Gold
<br />Corporation Ltd, and managed)
<br />Deming Whi[man
<br />Resident Manager
<br />Production and Development
<br />1985186 1989185
<br />Ore treated (tonnes) 262.900 201 900
<br />Recovered grade {gltonne) 3.76 2.97
<br />Gold recovered (ounces) 11,792 19,274
<br />Development (metres) 3,180 3,770
<br />Development and mining of the Wonga
<br />open cut continued during the year and
<br />provided 83% (87%) of the mill feed. Some
<br />ore won from development and limited trial
<br />sloping at the Magdala Decline, as well as old
<br />tailings from earlier mining operations, were
<br />also treated.
<br />The Magdala Decline advanced to a depth
<br />of 327 metres below the surface. A total of
<br />2,090 metres (3,190 metres) of crosscutting,
<br />driving and raising was completed during the
<br />year Preparations were made to rehabilitate
<br />the Magdala Shaft at the northern end of the
<br />feld.
<br />The Wonga Decline was commenced
<br />from the southern end of the open cut
<br />and advanced 362 metres to a depth of
<br />35 metres below the Floor of the open cut.
<br />A total of 17Z metres (nil) of crosscutting,
<br />driving and raising was completed during
<br />the year.
<br />Exploration and Ore Reserves
<br />In situ ore reserves at Wonga were
<br />estim~Red as follows:
<br />Junel986 June 1985
<br />Underground
<br />Probable ore (tonnes) 570,000 370,000
<br />Grade (g/tonne) 5 7 5.7
<br />Open Cut
<br />Proved and
<br />probable ore (tonnes) 110,000 270,000
<br />Grade (g/tonne) 3.8 4.0
<br />and for the Magdala Decline above the 290
<br />metre level the in situ ore reserves were
<br />estimated as follows:
<br />June 1986 June 1985
<br />Underground
<br />Proved and
<br />prooable ore (tonnes) 360,000 nla
<br />Grade (g/tonne) 6.4 n!a
<br />Underground development of the Magdala
<br />Lede continued to evaluate the ore
<br />potential indicated by surface diamond
<br />drilling. Dewatenng of the old workings
<br />continued to 290 metres below the surface.
<br />The surface diamond tlrllling programme
<br />at the Wonga open cut was completed
<br />having proved sufficient ore to warrant the
<br />commencement of a decline. Exploration
<br />continued m areas adjacent to the operation
<br />rnainly duetted at areas with potential (or
<br />near surface ore.
<br />Vatukoula Joint Venture
<br />(ZO% owned, and managed)
<br />~~ Graeme Sauer
<br />~,,,, Resident Manager
<br />Production and Development
<br />1985186 1984185
<br />Ore treated {tonnes) 444,700 139,700
<br />Recovered grade (gltonne) 5.37 4,91
<br />Gold recovered (ounces) 7ti,797 53,559
<br />Development (metres) 10,360 8.690
<br />Mining and treatment operations were
<br />expanded to an annual production rate of
<br />about 500,000 tonnes per annum from
<br />February 1986.
<br />Underground production was initiated from
<br />the Emperor Shatter Decline, No. 3 Level
<br />and from newly developed and remnant
<br />blocks at Wallace Smith, Cayzer and
<br />Borthwick Shafts. The remainder of
<br />production was mined from open cuts in
<br />the Loloma and Cardigan areas.
<br />The expanded underground development
<br />programme continued at all shafts and the
<br />Emperor Shatter Decline was advanced
<br />to the No. 5 sub-level position. Deepening
<br />of the Borthwick Shaft from No. 14 Level
<br />to No. l6 Level to provide accessto ore
<br />positions below current levels commenced.
<br />Crushing and milling capaaty was increased
<br />with the commissioning of a primary law
<br />crusher and primary ball mill. A new gold
<br />recovery plant was installed to meet the
<br />higher throughput.
<br />Exploration and Ore Reserves
<br />Ore reserves were estimated as follows:
<br />June 1986 June 1985
<br />Proved
<br />recoverable ore (tonnes) 1,7D0,000 770,000
<br />Grade (gltonne) 6.6 7.6
<br />Probable
<br />in situ ore (tonnes) 250,000 530,000
<br />Grade (gftonne) 8.0 8.6
<br />Reduction of the average mine grade
<br />mainly reflects a detailed reassessment of
<br />the Emperor Shatter remnant ore reserve
<br />based on recent development above No. 4
<br />Level and the introduction of additional
<br />lower grade open cut ore.
<br />Mine area tlnlling continued to define
<br />additional underground ore on the upper
<br />levels of Cayzer and Wallace Smith Shafts
<br />and adjacent to decline development south
<br />of the Emperor Shatter. Rotary drilling
<br />defined open cut ore positions at Korowere
<br />Hill and EmperorWest.
<br />Tavua Basin Joint Venture
<br />(50% awned, and managed)
<br />Exploration continued within the area of the
<br />Tavua Basin Joint Denture and a number of
<br />prospects have been identified and are
<br />being further evaluated.
<br />Tavua Basin Mining Joint Venture
<br />(50% owned, and managed)
<br />Malor exploration development was
<br />commenced to access a gold bearing
<br />structure, the Prince William Flatmake.
<br />At year end, the pre sinking phase of a
<br />5.5 metre diameter, 380 metre deep shah
<br />was completed to a depth of 60 metres and
<br />one plat cut. Installation of the headframe,
<br />winders and surface facilities in preparation
<br />for the main sink were well advanced.
<br />A crosscut was advanced 360 metres from
<br />the existing No. 13 Level of theValukoula
<br />workings and reached a position
<br />approximately 310 metres from the Prince
<br />William Elatmake.
<br />Exploration will be carried out on the
<br />known mineralisation and bulk samples will
<br />be taken to enable metallurgual test work to
<br />be tarried out.
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