This report describes how a limited number of preliminary exploration drill-hole assays from a mineral deposit can be used to design grid spacing that is both economic and efficient for subsequent evaluation drilling of that deposit. Relationships between desired precision of the estimate of grade of ore and drilling cost are used to determine the economic drill-hole spacing. The statistical concept of precision in estimating grade of ore is used to determine the efficient drill-hole spacing. Assay data from approximately 50 known copper deposits were studied, and the relationships of the statistical parameters of these deposits were computed. Drilling requirements for various precisions of the estimates of grade of ore were computed for some of these known deposits to serve as guides for drilling future copper deposits. The effect of various geologic factors on the trend in grade of ore and, therefore, on the drilling requirements is shown for certain deposits.

Developments in Geographic Information Technology have raised the expectations of users. A static map is no longer enough; there is now demand for a dynamic representation. Time is of great importance when operating on real world geographical phenomena, especially when these are dynamic. Researchers in the field of Temporal Geographical Information Systems (TGIS) have been developing methods of incorporating time into geographical information systems. Spatio-temporal analysis embodies spatial modelling, spatio-temporal modelling and spatial reasoning and data mining. Advances in Spatio-Temporal Analysis contributes to the field of spatio-temporal analysis, presenting innovative ideas and examples that reflect current progress and achievements.

Few knowledgeable people would deny that the field of mineral exploration is facing some difficult times in the foreseeable future. Among the woes, we can cite a worldwide economic uneasiness reflected by sluggish and at times widely fluctuating metal prices, global financial uncertainties, and relentless pressures on costs despite a substantial slowing down of the rate of inflation. Furthermore, management is forced to tum to more sophisticated and expensive technologies and to look farther afield to more remote regions, as the better quality and more easily accessible ore deposits have now been revealed. This rather gloomy outlook should persuade explorationists to cast about for a new philosophy with which to guide mineral exploration through the challenging decades ahead. Once already, in the early 1960s, a call for change had been heard (Ref. 30 in Chapter 1), when it became obvious that the prospecting methods of yesteryear, so successful in the past, could not keep up with the rapidly growing demand for minerals of the postwar period. The answer, a massive introduction of sophisticated geophysical and geochemical technologies backed by new geo logical models, proved spectacularly successful throughout the 1960s and the 1970s. But for both economic and technological reasons, the brisk pace of the last two decades has considerably slowed down in the early 1980s, as if a new threshold has been reached.