Joint Simulation of Grade and Rock Type in a Stratabound Copper Deposit
Cita de ítem
Math Geosci (2015) 47:471–495
Artículo de publicación ISI
This work deals with the joint simulation of copper grade (as a continuous
regionalized variable) and rock type (as a categorical variable) in Lince–Estefanía
deposit, located in northern Chile. The region under study is heterogeneous, containing
three main rock types (intrusive, andesite and breccia bodies) with different
copper grade distributions. To perform joint simulation, themulti-Gaussian and pluri-
Gaussian models are used in a combined form. To this end, three auxiliary Gaussian
random fields are considered, one for simulating copper grade, up to a monotonic
transformation, and two for simulating rock types according to a given truncation
rule. Furthermore, the dependence between copper grade and rock types is reproduced
by considering cross correlations between these Gaussian random fields. To
investigate the benefits of the joint simulation algorithm, copper grade and rock types
are also simulated by the traditional cascade approach and the results are compared.
It is shown that the cascade approach produces hard boundaries, that is, abrupt transitions
of copper grades when crossing rock-type boundaries, a condition that does
not exist in the study area according to the contact analysis held on the available data.
In contrast, the joint simulation approach produces gradual transitions of the copper
grade near the rock-type boundaries and is more suited to the actual data.
International Association for Mathematical Geosciences