Victoria’s billion-dollar hidden gold

Speaking at the AMEC mining congress on May 21st, GeoScience Victoria’s Paul McDonald described how the Government is attempting to uncover these resources through a three-year, $9 million initiative.
He said studies show that new GeoScience information acts as a major stimulus to increased exploration and discovery. Through producing new information and ideas, the Victorian Government hopes to stimulate the exploration community leading to greater investment and reversing the current downturn in resource expenditure in Victoria.
A move which would benefit communities particularly in regional Victoria and help re-establish Victoria as a leading gold producer.
Outputs for the Gold Undercover initiative will be produced as a series of sub-projects in six key thematic areas, as follows: Gold Resource Assessment; Gravity Data; VTEM Data; Lithogeochemistry study; Hydrogeochemistry study; 3D Interpretation Project.
Gold Undercover has already released its research results of its efforts at Bendigo and Stawell zones, and will soon issue its findings on the Melbourne zone.
In the Bendigo and Stawell zones, the project estimated between 15 and 70moz of orogenic gold was contained in up to 58 significant (>26,000oz) ore fields.
McDonald said up to 10 of those fields were expected to contain in excess of 1moz of gold.
Gold Undercover’s exploration work has employed some innovative methodologies including Lithogeochemistry and Hydrogeochemstry.
Lithogeochemistry defines gold deposits in terms of three overlapping haloes. It shows the lateral extent of alteration, effectively increasing the size of drill targets.
Using core from existing targets, Gold Undercover came up with alteration models for the Bendigo, Ballarat and Fosterville goldfields.
McDonald said the drilling footprint is large, up to 15km long by 6km wide in the Ballarat model), which is much more comprehensive than a single drill hole.
Hydrogeochemistry looks at gold and arsenic quantities in groundwater to find pathways to deposits.
Another major component of GeoScience Victoria’s gold exploration agenda has been 3D geological modelling, and the Rediscover Victoria 3D office is nearing completion of a 1:250,000 three dimensional map of Victoria. This map will include all the drilling knowledge attained by GeoScience Victoria for the past 150 years comprising onshore and offshore resources.
As part of an exploration grants program run concurrently by the Government, a total of 17 grants for exploration of greenfields targets have been issued to date.

Model partnership
In an Australian first, GeoScience Victoria and mining software and services company, Runge, have implemented a new and innovative system that allows GSV to seamlessly build, manage and distribute high-quality 3D models.
GeoScience Victoria Director, Kathy Hill, said GSV needed to develop a consistent and systematic environment in which 3D models in a range of formats could be prepared, manipulated, stored, discovered, visualised and delivered.
“The ability to quickly and easily access 3D models is critical,” Hill said. “These models need to be available to internal and external clients while at the same time protecting sensitive industry data.”
GeoScience Victoria’s existing systems for managing its large volume of geological data were not suitable for 3D data.
“Through a competitive tender process, mining software and services company, Runge, provided us with tools to manage 3D model data using their Mining Dynamics software,” Hill said.
The vision was to create a system that was the ‘first point of call’ for anyone building or requesting a model within GeoScience Victoria for use in and outside the organisation.
“Information management is integral to all GSV projects. The solution proposed by Runge and later implemented helped GeoScience Victoria move from a 2D to a 3D view of GeoScience information,” Hill said.
“Together we have implemented a 3D model management tool that brings together content-rich, standardised metadata, business processes and native model format transformation.”
Mining Dynamics receives and stores 3D models with the appropriate security, so that confidential models, for example exploration data, can only be accessed by the right people.
Runge developed a customised solution for GeoScience Victoria using Mining Dynamics’ core functionality, which is delivered through a web browser.