Geoscience Reference
In-Depth Information
Fig. 7.4
The point distribution
above is corrected to a block
(SMU) distribution below
into contact within each block can be averaged according
to the proportions of each within the mining blocks of the
model.
The impact and relative importance of this type of dilu-
tion depends on the geometry of the boundaries between
geological units and the differences in grade between units.
In high tonnage, massive base metals deposits the impact of
geologic contact dilution will be small if compared to depos-
its with complicated geometries, such as vein type or skarn
deposits, or a stratigraphically controlled deposit with sig-
nificant folding and faulting. For a fixed block size, say an
SMU, contact dilution can be characterized for individual
geologic zones or estimation domains by the ratio of surface
contact volume (SCV) to the overall extraction volume (V),
SCV/V, as measured by the volume represented by blocks
with geologic contacts to the overall volume of the unit.
