NI 43-101 Preliminary Economic Assessment - Verde Potash

Verde Potash Plc 12-13
Cerrado Verde Project
NI 43-101 Preliminary Economic Assessment
For the mineralization in question the IDW method was used with the search ellipse defined by
the axis of the geostatistical analysis. Was used the ellipse divided into four sectors. The search
radius were determined by semi variogram models. The parameters of the search ellipse radius
are presented in Table 12.2.7.1.
Table 12.2.7.1: Search Ellipse Parameters to Interpolate the Grades by the IDW And
Kriging Methods of Target 6
Radius Azimuth Factor Dip Factor Thickness Factor Min. Points by Sector Min. Count Fields
0.6667 324 222 30 3 2
1 324 222 30 2 2
2 324 222 30 2 1
3 324 222 30 1 1
4 324 222 30 1 1
100 324 222 30 1 1
After comparing the results of Kriging interpolation and IDW2 methods for target Target 6
(Table 12.2.9.1), it was decided to use IDW2 as the main interpolation method for the other
bodies. Search ellipse parameters used to interpolate the grades for the other targets are shown
in Table 12.2.7.2.
Table 12.2.7.2: Ellipse Search Parameters Used to Interpolate the Grades by the IDW
Method for Target 4, 7, 10 and 11
Radius Azimuth Factor Dip Factor Thickness Factor Min. Points by Sector Min. Count Fields
0.6667 150 100 15 3 2
1 150 100 15 2 2
2 150 100 15 2 2
3 150 100 15 1 1
4 150 100 15 1 1
100 150 100 15 1 1
The blocks for each zone of the mineralization were interpolated using only composite samples
belonging to the corresponding part of the body. During the interpolation process was used the
discretization process for each block, using a factor 4 for the X and Y axis, and a factor 2 for Z
axis. This makes it possible to evaluate each block in four positions and assign to the center of
the block the average of these values. This increases the accuracy of estimating the grade of
each block.
The constraints presented by each ellipse search sector were: the maximum number of points in
the sector - 5 and the minimum point total for the interpolation, which varied depending on the
size of the ellipse (from 3 to 1). Thus, the maximum total number of samples involved in the
interpolation was 20.
In the resources classification was used some parameters, as: the ellipse search radius (based on
geostatistical studies), the kriging variance and the minimum drillhole number used in the block
interpolation. In the resources classification of Target 6, inferred and indicated resources have
been allocated. For the indicated resource was allocated blocks interpolated by the first and
second search ellipses, with kriging variance less than 2, drillhole grid in the area about 200 by
200 m, and used in the samples interpolation at least two different drillholes.
SRK Consulting (U.S.), Inc. September 16, 2011
Cerrado Verde_NI 43-101 PEA_343500.020_007_KG