| Exploring for ore bodies is a vital part of sustaining a mining industry. Ore bodies are finite areas of mineralisation in the ground, and once they have been mined for the minerals they contain new ones need to be found. Being able to get onto land is necessary for exploration geologists to comb prospective terrain for ore bodies.Not all land is available, however. Some land is closed to this sort of activity, for example national parks. About thirty percent of Tasmania’s land surface is designated as a national park and therefore is out of bounds to exploration.
On another ten per cent of the Tasmanian land mass, access is allowed, but is strictly controlled because it is covered by statutory reserves. Special care must be taken so that any disturbance is carefully managed and restored. Lots of mineralisation occurs in Western Tasmania. It is likely there are many more ore bodies which could be mined. However most of the parks and reserves are also in this region, so access for exploration is limited over the most prospective ground. The Minerals Council, the Government and the public have to work closely together to strike a balance between making sure the beautiful environment in Tasmania is preserved, and the State having an economic future from its natural resource potential. |
How Exploration Takes PlaceModern exploration is carried out by professionals (exploration geologists) working with ground crews such as track-cutters and drilling teams. Minerals Resources Tasmania is responsible for ensuring that all exploration activity in Tasmania is of the highest standards and complies with the Mineral Resources Development Act 1995 and the requirements of other legislation which protects, for example threatened species and cultural heritage. In addition to the Act, there is the Exploration Code of Practice, which outlines current requirements, the approvals process and the controls and monitoring procedures. Modern technology has helped the exploration process become a low-to-nil impact scientific activity. The methods used include
The pictures right and below show some examples of geophysical models.
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Aeromagnetic Image of Southwest Tasmania. The large positive (red) anomalies are produced by the ultramafic rocks at Adamsfield, at one time a bustling osmiridium field |
Aeromagnetic image of Tasmania |
Radiometric image of Tasmania
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RehabilitationWhere there is a need to enter an area, and for example construct a track, strict protocols for development and subsequent rehabilitation must be followed. Some of the controls are making sure that visual impact is considered, that boggy areas are not crossed, or large areas cleared, that machinery is thoroughly cleaned afterwards, and that vegetation and topsoil is preserved for later use in the rehabilitation process. |
Drill rig at Red Hills |
Drill site and access track off Anthony Road West Coast Tasmania. – During Use and Rehabilitated |
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Planning for the FutureAll the mines currently in operation in Tasmania are due to mine out their current ore body within ten or fifteen years. New ore bodies need to be found now, because it takes five to ten years from the stage where an economic ore body is found, to the stage where a mine is opened. In Tasmania more than a billion dollars is returned to the State as a result of mining and minerals processing activity. Therefore to ensure a continuation of economic prosperity, exploration is crucial. In 2002 the Minerals Council together with potential and existing explorers, mining interests and the Government held a crisis meeting to address the issue of the dismal reduction in mineral exploration activity that has been occurring in the past decade. See accompanying graphs - The result was an undertaking by government to support three-dimensional modelling of the exiting geological data of Western Tasmania held by MRT to encourage explorers to consider Tasmania as a potential worthwhile mining proposition. The Government committed $300,000 to fund this study. In addition an integrated database and a prospectivity analysis have been undertaken as part of the modelling process. The project was conducted by the Predictive Minerals Discovery Cooperative Research Centre at the University of Melbourne, with input from MRT and the CODES Special Research Centre at the University of Tasmania. A further $125,000 was committed by government for marketing mineral exploration opportunities. A promotional CD has been developed called Mineral Exploration and Mining Investment Options in Tasmania, and several displays across the country have been undertaken. The outcome has been very encouraging. In 2004 more than 20 exploration companies are operating in Tasmania – both major players and juniors. Interest has also been directed to reprocessing the old Hellyer tailings. In addition existing mines have increased their exploration activity. |
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ResourcesThere are several other projects available to further assist explorers and mineral companies. These are TIGER, the core library, and the Western Tasmanian Regional Minerals Program. The Western Tasmanian Regional Minerals Program is a tripartite agreement with the Commonwealth and Tasmanian Governments and the Minerals Industry. The aims of this program have been to:
TIGER (Tasmanian Information on Geoscience and Exploration Resources) is Tasmania’s geological and mineral exploration knowledge base. TIGER enables you to -
TIGER is an archive of historical information for -
The Core LibraryThe drill core library, housed at Mineral Resources Tasmania, is a facility holding almost 300km of rock-core samples that have been collected from drilling rigs and infrastructure projects around Tasmania over the past 70 years. Studying the core samples provides a ready source of information for potential prospectors and investors about particular areas, and avoids the expense of further drilling. The Henty gold mine in Western Tasmania was discovered through an investigation of gold bearing core that had been drilled at an earlier time. For information about these resources go to www.mrt.tas.gov.au |
Land Management CommitteeThe Minerals Council maintains a standing Land Management Committee. Its task is to represent the industry in all matters related to access to land and exploration and to hold forums to allow the exchange of geological or exploration information. |
