The copper ore reserves at the Chuquicamata mine were re-estimated
during March to June 1994, as part of a comprehensive audit of the
mine's overall short- and long-term planning. The basic principles
essential to all ore reserve estimates were implemented viz: 1. A detailed study of the geology, in this case particularly of the
orientations of structural features of copper mineralisation and the
subdivision of the orebody into geologically homogeneous sections,
2. the use of both drillhole and blasthole data sets, 3. statistical and geostatistical analyses of both data sets to model
anisotropic spatial structures for all the geologically homogeneous
sections, 4. block kriging using both data sets individually; and 5. a comprehensive validation of the block valuations to confirm the
absence of global and conditional biases and to quantify the actual
improvement achieved in the overall quality of the estimates
compared to those executed on earlier techniques.