Presently, orebody modelling consists basically of fitting a mathematical
model to represent spatially a certain geological variable, generally grade.
An orebody model is constructed from a set of sample data obtained from
various locations in the orebody, thus it is only one form of representation
of the true phenomena. Checking the compatibility of the data with the
modelling procedure is the most important factor when assessing
confidence in the orebody model. The level of confidence in the model
will depend on the adequacy of the data set and the validity of the basic
assumption required by the modelling method. Fractal geometry is one
way of modelling the spatial distribution of a geological variable in an
orebody geometry. Fractals can be used to interpolate the Z(x) geological
variable at unsampled sites. The concepts of self similarity and self
affinity that form the basic assumption of fractal geometry theory which
areinvestigated. The population distribution of the geological variable in
question must be examined to determine the appropriateness of both
fractal geometry and geostatistical modelling methods. The selection of
the most appropriate method depends on the available data. A researcher
or a practitioner needs to understand the strengths and limitations of the
various modelling methods before choosing the most appropriate method.
This study investigates the fractal properties of grade distribution using
the variogram and some proposed variations as techniques to measure the
fractalness. The aim is to assess applicability of fractal geometry theory to
modelling ore grade distribution in a deposit. A comparison of the results
demonstrates the methods which better capture the spatial behaviour of
the variable under study.