Geoscience Reference
In-Depth Information
All Minzones Assays CuT
All Oxide Assays CuT
Number of Data 56018
number trimmed1991
mean
Number of Data
16864
number trimmed
41145
0.6183
mean
0.8827
std. dev.
0.7517
std. dev.
0.7586
0.300
coef. of var
1.2157
0.200
coef. of var
0.8594
maximum
19.7200
maximum
19.7200
90th quantile
1.5800
90th quantile
1.8200
upper quartile
0.8200
upper quartile
1.0900
median
0.3855
median
0.6300
0.150
lower quartile
0.1040
lower quartile
0.4200
0.200
10th quantile
0.0300
10th quantile
0.3100
minimum
0.0010
minimum
0.0130
0.100
0.100
0.050
0.000
0.000
0.00
1.00
2.00
3.00
4.00
0.00
1.00
2.00
3.00
4.00
CUT
CUT
Fig. 14.4
Histogram and basic statistics of all samples, total Cu grade
Fig. 14.5
Histogram and basic statistics of all samples, total Cu oxide
grade
tions, and they will be treated separately in the mine plan.
The final estimation domains used are constrained by the
amount of information available, which requires that some
data be grouped. The main estimation domains defined are:
1. Domain = 0 (leach) includes all samples mapped as min-
eralization type “leach”, and also all other samples that
are mapped as gravels or ignimbrites. This is waste mate-
rial.
2. There are three oxide domains. The first has better oxide
grades with phyllic, argillic, and silicified alterations, and
within intrusive rocks (porphyries and breccias).
3. A second oxide grade spatial distribution is found within
the andesites. These have lower, but still interesting Cu
grades.
4. The third oxide domain is a lower grade domain, and cor-
responds to all oxide mineralization with potassic and
cloritic alterations. This mineralization is located on the
fringes of the deposit, and is volumetrically disjointed and
overall small in comparison to the two previous domains.
5. The fourth and fifth domains are supergene sulfide min-
eralization mapped with phyllic, silicified, and argillic al-
terations. The porphyries have better grades and are spa-
tially distinct from the breccias located in the central and
southern areas of the East sector of the deposit.
6. Supergene sulfides with phyllic alteration in andesites
tend to have low grades, and are found towards the edge
of the deposit, around the rocks that intruded them. This is
also true of the supergene sulfide mineralization that has
potassic and cloritic alteration, and thus they are grouped
in a single domain.
7. The mixed sulfide-hypogene mineralization was estimat-
ed separately, despite being a set of spatially disjointed
bodies and with small overall volume. This is necessary
because this transition zone is distinct from either sulfide
or hypogene mineralizations.
A
ll Sulfide Assays CuT
Number of Data 11785
number trimmed46224
mean 1.2043
std. dev. 0.8987
coef. of var 0.7462
maximum19.4000
90th quantile
0.120
2.2300
upper quartile
1.6200
median
1.0007
0.080
lower quartile
0.5772
10th quantile
0.3400
minimum
0.0010
0.040
0.000
0.00
1.00
2.00
3.00
4.00
CUT
Fig. 14.6
Histogram and basic statistics of all samples, total Cu sulfide
grade
• From Table
14.4
, it can be seen that the oxide and sulfide
mineralization are the only two types that have significant
soluble Cu (SCu) grades.
14.1.7
Estimation Domain Definition
The definition of the grade estimation domains was done fol-
lowing the general guidelines suggested in Chap. 4. In the
case of Cerro Colorado, the estimation domains (or geologic
units, “UGs”) are based on a combination of mineralization
type, lithology, and alteration, and are intended to capture the
mineralization controls. It was recognized that mineraliza-
tion type is the major mineralization control and introduces
mineral processing considerations in the resource model. For
example, hypogene mineralization with Supergene Sulfide
mineralization have different ore genesis, spatial distribu-
