165
Figure 6. Cokriging maps obtained from ordinary multicollocated cokriging (left: moving neighborhood (OMCK – Moving) and middle: unique neighborhood (OMCK – Unique) and right: traditional
ordinary cokriging (isotopic search – moving neighborhood (IOCK)); first row: estimated gold grade
and second row: estimated copper grade.
Figure 7. Grade-tonnage curves for estimated gold and copper grades.
the ability in precisely calculation of estimation variance. Application of variance map in mining industry, for instance, involves the mineral resource categorization based on international
standards. This parameter is an index of data configuration, ranking the resource blocks model
on the basis of available information (e.g., borehole data) and level of confidence (Rossi and
Deutsch, 2014). The ordinary multi-collocated cokriging variances in both cases of moving
and unique neighborhoods are then computed block-by-block and compared with the variance measures obtained from traditional ordinary cokriging algorithm with isotopic search and
moving neighborhood. In Figure 7, the fraction of tonnage-cut off grades are illustrated as
well. The differences among the values are not very significant for three methodologies.
Figure 8 depicts the distribution of cokriging variance in boxplot. As can be seen, the ordinary
multi-collocated cokriging resulted in minimum variance, while the isotopic ordinary cokriging
produces the maximum variance. The output for cokriging variance in multi-collocated cokriging with moving neighborhood is approximately closer to ordinary multi-collocated cokriging with unique neighborhood. This results corroborate the trustworthy in cokriging variances
:!: B o.s ·
" >
0
il 0.6
~
§
B 0.4 ·
"-<
0
§
-~ 0.2
u.
"
"
"
10
40
~
20
"
100 200
300 400
Easting
-·~
I
....
I
&.
c
3
100
200 300 400
Easting
Tonnage vs. cut-off for A u
r-----=c;:::;;:-:--;---c----,
20
30
Cut-off grade
40
100 200 .100
Eusting
100 100 300
Easting
50
400
400
'?
3
§ 0.8
~
0
.g 0.6
" ~
=
g 0.4
'0
= 0
-~ 0.2
"(jQ()
500
400
~
~
EJoo
z
200
100
600
500
400
= gJoo
w
z
200
100
50
40
30
..
20
"
100
200 JOO 400
Easting
3 c
100
200
JOO 400
Eusting
Tonnage vs. cut-off for Cu
- - OMCK-Moving & OMCK-Uniqm:
- - lOCK
o L---~--~~------~--~--~
0
Cut-off grade
Figure 6. Cokriging maps obtained from ordinary multicollocated cokriging (left: moving neighborhood (OMCK – Moving) and middle: unique neighborhood (OMCK – Unique) and right: traditional
ordinary cokriging (isotopic search – moving neighborhood (IOCK)); first row: estimated gold grade
and second row: estimated copper grade.
Figure 7. Grade-tonnage curves for estimated gold and copper grades.
the ability in precisely calculation of estimation variance. Application of variance map in mining industry, for instance, involves the mineral resource categorization based on international
standards. This parameter is an index of data configuration, ranking the resource blocks model
on the basis of available information (e.g., borehole data) and level of confidence (Rossi and
Deutsch, 2014). The ordinary multi-collocated cokriging variances in both cases of moving
and unique neighborhoods are then computed block-by-block and compared with the variance measures obtained from traditional ordinary cokriging algorithm with isotopic search and
moving neighborhood. In Figure 7, the fraction of tonnage-cut off grades are illustrated as
well. The differences among the values are not very significant for three methodologies.
Figure 8 depicts the distribution of cokriging variance in boxplot. As can be seen, the ordinary
multi-collocated cokriging resulted in minimum variance, while the isotopic ordinary cokriging
produces the maximum variance. The output for cokriging variance in multi-collocated cokriging with moving neighborhood is approximately closer to ordinary multi-collocated cokriging with unique neighborhood. This results corroborate the trustworthy in cokriging variances
:!: B o.s ·
" >
0
il 0.6
~
§
B 0.4 ·
"-<
0
§
-~ 0.2
u.
"
"
"
10
40
~
20
"
100 200
300 400
Easting
-·~
I
....
I
&.
c
3
100
200 300 400
Easting
Tonnage vs. cut-off for A u
r-----=c;:::;;:-:--;---c----,
20
30
Cut-off grade
40
100 200 .100
Eusting
100 100 300
Easting
50
400
400
'?
3
§ 0.8
~
0
.g 0.6
" ~
=
g 0.4
'0
= 0
-~ 0.2
"(jQ()
500
400
~
~
EJoo
z
200
100
600
500
400
= gJoo
w
z
200
100
50
40
30
..
20
"
100
200 JOO 400
Easting
3 c
100
200
JOO 400
Eusting
Tonnage vs. cut-off for Cu
- - OMCK-Moving & OMCK-Uniqm:
- - lOCK
o L---~--~~------~--~--~
0
Cut-off grade