Introduction

The pmd*CRC-developed software, to which Predictive Discovery Pty Ltd ("PD") has contractual access, consists of various codes that enable skilled users to simulate aspects of ore formation in space and time. These codes employ algorithms which use well known laws and principles of mechanics, physics and chemistry. Geological researchers have been using such codes for over 20 years. However, prior to the pmd*CRC, their application to practical mineral exploration was very limited. Thus, the pmd*CRC’s key advance was to enable genuinely efficient and effective application to a wide variety of mineral targeting problems. Earlier attempts at application were hindered by:

• a lack of versatility in the codes for application to problems relevant to mineral targeting;
• slowness of application, meaning that results were normally obtained in projects lasting one to three years, too long for effective application in normal exploration work programs; and an academic approach to applying the software.

Case histories where the technology has been applied effectively to mineral exploration problems and have been publicly presented include the following:

• Stawell-Kewell Belt, Victoria - where computer simulations of the pattern of mineralisation adjacent to the Magdala Basalt at Stawell was followed by computer prediction of mineralisation at the Kewell prospect, located 100km to the north underneath 100 metres of cover which resulted in a first drill result of 4.1m at 12.6 g/t Au (see Figure 1).
• Kundana, Western Australian Eastern Goldfields – where simulation of many structural geology scenarios revealed that a previously unrecognised fault orientation could be optimal for the formation of gold mineralisation. This was followed by drilling which intersected a laminated quartz vein containing more than 5g/t Au in an area in which more than 80 holes had failed to intersect greater than 1g/t Au.
• Century, Queensland – where simulation of ore formation in this giant zinc-lead deposit led to a new conceptual model for ore genesis and identification of numerous targets north of Century for follow-up drilling.

Figure 1: Numerical model results from Stawell Mine (left) and Kewell prospect (right), Western Victoria. At Stawell, fluid flow vectors from numerical modelling (arrows) compare well to the location of known mineralisation. At Kewell, 100km to the north, numerical modelling predicted gold mineralisation (circled arrows) resulting in a series of ore grade drill results. Source: Roberts et al, SGA Conference Dublin, 2007.

Ongoing interest in the technology is attested by the growth in client usage, both in numbers  (see Figure 2).



Figure 2: Industry uptake.

In addition, application of pmd*CRC mineral system research outcomes has been publicly acknowledged by St Ives Gold Mines as having generated discovery successes at the St Ives mine in Western Australia. The pmd*CRC’s approach to mineral system understanding underpins PD’s exploration methodology.

Application of the pmd*CRC software and mineral system method follows a well developed workflow which has been established through many projects with mining companies over the past 6 years. This involves a model validation stage where characteristics of the target mineralisation (e.g. geometry or mineralogy) from the same geological terrain are simulated. This is followed by a prediction stage, where the intensity and location of mineralisation can be predicted. Drill tests to follow up the predictions provide new geological information that can be fed back into the analysis. In this way, the path to discovery can be shortened as mineral explorers only test targets that the simulation shows as likely to contain mineralisation.