comprehensive picture of the daily ore situation. The data are recorded on the daily ore delivery sheet located in the geology office. A test mill is also available to provide simulated mill recovery of selected drill-core intervals, pit- muck and blast-hole samples, mill feed, tailings and reject samples. Weekly and monthly grade control sheets are maintained to show the accuracy of the geological predictions versus test mill sample results and actual mill recovery. Weekly and quarterly min- ing schedules are also provided to mine and mill per- sonnel, in conjunction with the planning department, to aid in pit planning and scheduling. The mine geologist, through his department, is completely responsible for all ore mining and sched- uling, and coordination with milling and marketing personnel. Ore Reserves GENERAL Ore reserves mineable by currently planned open- pit methods were estimated at December 31, 1977 to be 16,277,000 tons at a 3.0% C.C.R.G. (Corrected Core Reading Grade) cut-off grade, with waste stripping quantities needed to liberate this ore estimated to be 48,042,000 bey (bank cubic yards). A further nearly 8,000,000 tons of ‘geological’ reserves, outside pre- sent pit limits (to the 5000-ft level), have been par- tially defined by diamond drilling. ESTIMATION Ore reserve estimation is carried out using the data obtained from adit mapping, blast-hole logging, pit mapping and diamond drill information. Natural- ly, diamond drill core is of prime importance in pro- jecting fibre zones. The diamond drill core is logged in 5-ft (1.5-m) intervals, with a physical counting of all fibre vein- lets of 1/16-in. length or greater, the procedure being repeated by a second individual after 90-degree rota- tion of the core. Actual geological logging of the core for rock types, alteration parameters, shear zones, etc., is also carried out. The two grade esti- mates are averaged and equated over the distance actually read within the 5-ft (1.5-m) interval (i.e., assuming core lost has an equal grade to that re- covered). This grade estimate is then corrected for the angle of the fibre veinlets (assume random 45 degrees) to the core, to produce a C.C.R.G. Total Sixteenths Read C.CRG.= FeotRead x 12X 16 X Cosecant of 45° The 5-ft (1.5-m) intervals are then combined to yield a 80-ft (9.1-m) bench average grade with correspond- ing length and quality data. Calculation involves the construction of 100-ft (30.5-m) square blocks around each drill hole (where possible) to produce a 100-ft (30.5-m) by 100-ft by 80-ft (9.1-m) (bench height) planning prism. Using data compiled from adit bulk sampling and historical mill records, the block is designated as AA or A type ore. AR Ore iC i CRG ree nears. Caer ee treme 8.00% + Averagenliensthistas:sancocecciec cn scee ee 0.150 in. + Percentage of % m.....................-. 15% + AOre Ss. -= ACC RIG ae eee Psu ee eee eee 3.00% + Quality parameters decided on daily mining Block data may be adjusted for geological reasons, such as contact areas, etc. The data for the block are then assigned block numbers and fed into the 9825A/ 9871A Hewlett Packard mini-computer. Print-outs from the computer yield a C.C.R.G. grade calculation, length distribution data, ore type (AA and A) and ORE DEPOSIT MODEL FILES-PHASE (PAH version July 1977) EXAMPLE ONLY AVG. 1/2+ 3/8 5/16 1/4 3/16 1/8 1/16 AA BLOCK CCRG LENGTH INCH INCH INCH INCH INCH INCH INCH ORE LEVEL BLOCK AREA PRCNT INCHES PRCNT PRCNT PRCNT PRCNT PRCNT PRCNT PRCNT AREA 5690 1 1.00 2.90 0.104 3 5 8 2 4 31 7 0.00 2 0.64 2.08 0.089 0 6 4 6 15 28 41 0.00 3 1.00 2.09 0.100 2 3 6 8 2 30 39 0.00 4 1.00 2.80 0.111 7 6 7 7 13 23 37 0.00 5 1.07 3, 5il 0.121 12 9 9 6 15 17 32 0.00 6 1.07 7.49 0.123 8 2 8 5 15 25 27 0.13 7 0.50 8.39 0.136 9 6 7 6 6 24 22 0.00 10 1.01 6.85 0.115 4 6 5 2 6 29 28 0.00 11 0.96 8.07 0.132 7 8 5 14 16 27 23 0.65 12 1.05 9.28 0.148 10 10 6 17 7 23 17 0.36 13 0.44 3.99 0.122 5 8 4 3 17 27 26 0.00 14 0.30 2.14 0.108 0 4 0 16 14 36 30 0.00 15 0.92 3.60 0.109 5 8 3 12 14 29 29 0.00 16 0.66 7.19 0.134 11 9 6 12 13 25 24 0.00 17 1.00 10.77 0.158 17 11 9 3 12 21 17 0.48 18 0.97 7.65 0.158 16 7 9 6 17 31 15 0.09 19 0.56 5.81 0.164 20 12 7 6 10 20 15 0.00 20 0.55 8.41 0.139 12 11 6 1 13 27 20 0.00 21 0.88 6.72 0.134 7 9 8 14 15 26 21 0.00 22 1.00 10.67 0.148 16 8 6 13 15 24 18 0.13 23 0.53 9.78 0.142 13 7 i 13 15 25 20 0.38 24 1.14 8.89 0.135 11 6 8 14 15 24 22 0.21 2 0.48 5.54 0.127 7 6 6 16 15 27 23 0.28 26 1.05 5.91 0.137 10 8 7 14 15 26 20 0.00 27 1.02 10.72 0.138 7 11 5 13 16 32 16 0.01 FIGURE 8 — Computer print-out — 5690 Bench data. =