100feet I 1

Figure 6.7. Diamoud dri l l hole plan and polygtis for the Bonanza copper depo&it.

Table 6. Assav Data for Drill Hole D - l Interval (ft) Thicknes Grade Grade , : Tliickne^s

sfftl % Cu 3-100 100 P . 31 Below Cut^off

1 0 0 - 1 1 0 10 0 47 4 . 7 0 1 1 0 - 1 2 2 12 0 72 e . 75 1 2 2 - 1 3 0 8 0 56 7 . 6 8 1 3 0 - 1 5 0 2 0 1 : 4 2 0 . 8 0 1 5 0 - 2 0 0 50 0 82 4 1 . 0 0 2 00 -22 0 20 0 54 1 0 . 80 2 2 0 - 2 5 0 3 0 0 42 12 . 60 2 5 0 - 2 7 0 50 35 B e l e w C u - o f f

150 1 0 6 . 4 3 T h i c k n e a s a n d Grade * T h i c k r . e s 3 abe ve c u t e f f

A vera ge Grade D r i l l Hole D - l T Thichness. * Grade 106.43

Thickness. 150 :0.71%CU

Table 7. Ore Reserves for Bonanza Copper Deposit Polygon Area Thickne* Voluine Tonnag Tons Grade T O I I * Grade

f i f i s fffl (ti) e Factor % Cu D - l 5320 150 7 9 8 , 0 0 0 12 . 5 3 , 8 4 0 0 . " 1 4 5 , 3 2 D 2 5300 135 7 1 5 , 5 0 0 1 2 . 5 5 7 , 2 4 0 0 . 66 3 7 , 7 7 8 D - 3 4 4 0 180 7 9 2 , 0 0 0 12 . 5 3 , 3 6 0 0 . 82 5 1 , 9 5 5 D - 4 552 0 175 9 6 6 , 0 0 0 12 . 5 7 7 , 2 8 0 0 . 75 5 7 , 9 6 0 D - 5 8 0 0 155 1 0 5 , 4 0 0 1 2 . 5 3 4 , 3 2 0 1 . 0 0 3 4 , 3 2 0 D - i 4S0 180 8 9 2 , 8 0 0 1 2 . 5 7 1 , 4 2 4 0 . 57 6 9 , 2 8 1 D - 7 452 0 250 1 , 1 3 0 , 0 0 0 12 . 5 90,4O0 1 . 2 1 1 0 9 , 3 8 4 D 8 4 40 240 1 , 1 1 3 , 6 0 0 1 2 . 5 8 9 , 0 8 8 1 . 36 1 2 1 , 1 5 9 D - 5 5840 150 8 7 6 , 0 0 0 1 2 . 5 7 0 , 0 8 0 0 . 93 5 , 1 7 4

u 10 4840 135 6 5 3 , 4 0 0 1 2 . 5 5 2 , 2 7 2 0 . 87 4 5 , 4 7 6 E - 1 1 3760 120 4 5 1 , 2 0 0 12 . 5 3 6 , 0 9 6 0 . 81 2 9 , 2 3 7 D - l 2 4270 165 6 3 7 , 2 0 0 1 2 . 5 5 0 , 9 7 6 0 . 75 3 8 , 2 3 2 D-13 4800 135 6 4 3 , 8 0 0 1 2 . 5 5 1 , 8 4 0 0 . 68 3 5 , 2 5 1 Toral 8 5 3 , 2 1 7 30 ,553

Average Grade Eiitiie Deposit = = = 0.92 %CTI T T o i i S j 85S.216

Table S. Assay Data for the Ojala Copper Deposit Dril l Hole Tliickiies Grade

%Ca D - l ?: 0 . 93 D-2 75 0 . 77 D-3 60 0 . 82 D-4 100 1 . 05 D-5 75 0 .72 D-6 6C 0 . 49 D-7 105 1 . 63 D-3 i: 0 . 91 D-9 ?: 0 . 86

D-10 75 0 .74

Given this data, tlie totmage and grade calculaiiou for mangle T I woii ld be a& follow:

Area = 4400 f r (by geometry)

Table Sa. Grade and Tonnage Calculation for Triangle T I . Drill Eole

D - l D-4 D-5

T o t a l

Thicknes

50 100

75

Grade % a i 0. 93 1 . Z 5

Grade * Thickness

46 .5 105.0

54 . 0 1 . .

Average Grade = V Thichnes&j * Grada 205.5

225 = 0.91%Cu

y Tkickue&s,

Tonnage = rea * average thickness * tonnage factor = 4400 *(225/3)/12.5 = 26.400 tons.

Table 9. Ore Reserves for the Ojala Copper Deposit. Triangle Dri l l Holes Tons Avg. Grade

% Cu Tons * Grade

T - l D - l , D-4 , D-5 26 ,400 . 51 24 ,024 T-2 D - l , D - 2 , D-4 26 ,400 0. 54 24 ,816 T-3 D - 2 , D -3 , D-4 22 ,500 0. 91 20 ,475 T-4 D-3 , D-4 , D-7 22 ,260 1.23 27 ,380 T-5 D - 4 , D -6 , D-7 I B , 5 5 0 1 15 21 ,332 T-6 D - 4 , D-5 , D-6 27 ,260 0 .79 21 ,535 T-7 D-6 , D-7 , D-1C 26 ,240 1 . 07 28 ,076 T-8 D-7 , D-5 , D-10 40 ,500 1 15 46 ,575 T-9 D - 3 , D - 7 , D-8 24 ,418 1.2C 2 9 , 3 0 1

1-1C D - 7 , D-8 , D-8 28 ,917 _ . 15 3 4 , 4 1 1 T o t a l 263 ,445 2 77 927

Average Grade Eiitire Deposit =

Average

V Tons. * Grade. 277,927

y Tons.

Grade = 277,927/263.445 = 1.05 % Cu

263,445 = 1.05%Cu

7.8 Calculatiou by Section

The basis of this method is to calclate a block o f ore that is bounded by regularly spaced cross sections (see Tables 10 and 1). The followmg equation illus>trates the detailed calculation of a typical block o f oreby the cross section nierhod. The ore outline o f each bounding section is divided into reas of influence based on the dri l l hole or other sample data. The reas of mflueiice are then either plamnietered or calculated geornetrically. The individual reas are totaled for each section and the volume calculated by the average and rea formula:

where A is rea on section and L i s a constant section spacmg. or when using only U T O adjacent sections:

The volume is then converted to tons by applicarion of the appropnate tonnage factor.

Figure 6.10 shows rwo cross sections spaced 30.48 m (100 ft) apart. These sections show a tabular dippmg vem sainpled by a surface rrench, rwo dri l l holes per section, and one crosscur per section. The vein is assuined to be copper ore wit l i a tonnage factor o f 9.5 cu per ton.

V = ( A + 2A: + 23 ...Ao)/2 L

V = C A 1 + A ! ) /2 * L

Block Average Grade:

Section Area

(SI ft)

Average Grade, % Cu % C u F t s

10W 20N

3260 4896 8156

1.81 1,75

5 9 0 1 S 5 6 3

1 4 4 6 3

Average block grade 14463 8 I 5

- 1.77% Cu,

Volunte of Ore Block:

rea section 100N + rea section x 2CHW X section spacng

v = 2

Tonnage

The geologic reserve of this deposir between 100N and 200N is 38934 ton (42.926 st) wi t l i an average grade of 1.77% Cu. Similarly. the reserve calculations can be extended north and south to cover the entue nunable smke length of the vein by adjacent pahs of sections.