Bruce McDonald, now with Sydney-based MMS Mining Consultants, said he used Autodesk products to help identify new gold deposits at Vatukoula. As project exploration geologist he was given the task of finding new gold deposits before remaining ore reserves were depleted when Emperor became involved in the project. Original owner WMC pulled out of Vatukoula in 1991, believing its potential was limited.

“My first impression was that mining had exploited mineralisation associated with only a portion of a very large epithermal system. Before we could make a clearer assessment we had to address the issue of transferring all the maps and data from paper format into a computer-based system,” McDonald said.

Autodesk software products used in the successful rejuvenation of the Vatukoula gold mine in Fiji are now playing a part in owner Emperor Mines' attempts to promote its success.

“We actually went back to the original 1927 cloth maps to start plotting the terrain, adding survey data, geological information, topographical details and geophysical data to create a complete digital picture of the mine. Using AutoCAD, we were able to compile and lay over data sets from the various disciplines, which was almost impossible to do with any of the mining packages available at that time, and soon identified a number of anomalies requiring further investigation.

“These were evaluated in relation to underground information and we identified two areas for testing by deep surface exploratory drilling, which led to the discovery of a large resource of high grade gold mineralisation over a four-year period. Our success in locating new gold-bearing ore led to a significant improvement in the (Emperor) share price as well as support from the Fijian government to help maintain the operation. The mine currently has reserves of around 15 years because of this, and more recent discoveries.”

McDonald left Emperor in 1995 but was approached by the company again in July last year to create a video presentation on Vatukoula to help attract further investment.

“This was an enormously complex project and required compiling a huge array of data using a selection of Autodesk products to meet the various challenges,” he said. “We took existing 2D survey data and topographic information and imported it into Autodesk Civil Design to create around 800km of roads and a 1200sq.km DTM model covering the north-western portion of Viti Levu, using different tools within the application to create 3D models of land surfaces and road paving. We used the predecessor to AutoCAD Land Development Desktop, AutoCAD Map R3, and Autodesk Survey to edit mine survey files for levelling errors and grid transformations, as well as providing the framework for erosion simulation and solid modelling over 450km of underground tunnels in Gemcom mining software.

“The final product is incredibly detailed, comprising accurate models of two towns, a complete representation of the mine, which covers a spatial area of 3km by 4km by 1km, located on the western margin of a massive extinct volcano. In addition, the model includes full details of all underground mining features and geological structures to a depth of 4km.”

McDonald said all data was compiled in AutoCAD Map R3, an “ideal environment” because it could manipulate large amounts of information while maintaining multiple grid systems.

“A lot of the mining applications on the market become unstable with really large datasets, but I’ve found that AutoCAD always delivers a great result. This was particularly important on this project, because some of the models required up to 1.3 gigabytes of storage with individual files greater than 230 megabytes,” he said.

Underground workings started as 3D lines. AutoCAD was used to generate input for a mining application to extrude the tunnels to produce solid models. The mine geology was digitised in AutoCAD Map R3 and levelled to match underground levels, which were wired, to create solid models of veins, dykes, faults and the massive caldera contact (the volcanic crater margin) to a depth of 4km. “This aspect of the project alone involved enormous geometric complexity and took six weeks to complete, but if we’d been using other products, we’d still be working on it today,” McDonald said.

Part of the brief for the video called for an animated simulation showing how the volcano collapsed to form the current land surface and provide the subsequent conditions for the gold mineralisation at Vatukoula. McDonald said he used Autodesk’s visualisation and animation software 3D Studio MAX to model the topography as it would have looked before the conclusion of volcanic activity, then showing a lava flow eruption, and finally portraying how the land surface collapsed over time until it became the current land surface.

“The idea was to give people without a geological background an understanding of how the features of the mine were formed over time. On a more technical level, we’ve added geophysical information to explain the relationships between specific geological structures and geophysics, which is an aid in locating blind gold deposits. We’ve also built the next five years of projected mining activity into the model to demonstrate its long term potential,” McDonald said.

The completed video will form part of Emperor’s corporate presentation at the upcoming Diggers and Dealers conference at Kalgoorlie, Western Australia.

McDonald said now that so much data had been compiled into a comprehensive model and source files were available, Emperor had a powerful tool for staff to use in planning, staff training and day-to-day operations. “Because we worked with real world coordinates, every element of the model is accurate. Another advantage of our decision to use AutoCAD is its compatibility with a huge range of products, so the data can be exported into a range of formats for use by any discipline associated with the mine,” he said.