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australia's identified mineral resources 2005 - Geoscience Australia

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AUSTRALIA’S IDENTIFIED MINERAL RESOURCES <strong>2005</strong><br />

Gold has a range of uses but the two principal applications are as an investment instrument and in<br />

the manufacture of jewellery. Secondary uses, in terms of the amount of gold consumed, are in<br />

electronic and dental applications.<br />

Resources<br />

<strong>Australia</strong>’s gold <strong>resources</strong> occur and are mined in all States and the Northern Territory. At the end<br />

of 2004, total <strong>Australia</strong>n gold <strong>resources</strong> were 997 t higher than at the end of 2003. After allowing for<br />

the replacement of those <strong>resources</strong> lost to production (259 t), newly delineated <strong>resources</strong> added to<br />

the national inventory totalled 1 256 t (40 Mozs) in 2004. Inventories grew in Queensland, Victoria,<br />

New South Wales and South <strong>Australia</strong>.<br />

<strong>Australia</strong>’s EDR rose by 207 t (6.7 Mozs) in 2004 to 5 589 t and accounted for 82% of total demonstrated<br />

<strong>resources</strong>, a small increase on the share in 2004. In 2004, EDR increased in New South Wales,<br />

Tasmania, South <strong>Australia</strong> and the Northern Territory. Western <strong>Australia</strong> continued to dominate EDR<br />

with 58% of the national total, which was a slightly reduced share. In 2004 its EDR fell by 44 t to 3 243 t.<br />

South <strong>Australia</strong> had the second largest EDR. In the Northern Territory, EDR rose by 33 t to 213 t.<br />

Subeconomic demonstrated <strong>resources</strong> fell by 334 t in 2004. All the reduction occurred in the<br />

paramarginal category, which fell by 335 t to 1 102 t. Western <strong>Australia</strong>n paramarginal <strong>resources</strong> rose<br />

by 344 t to 772 t, which was 70% of total paramarginal <strong>resources</strong>. Increases also occurred in all other<br />

jurisdictions except the Northern Territory where paramarginal <strong>resources</strong> halved. The major reduction<br />

in paramarginal <strong>resources</strong> is attributed to a number of factors but particularly the reclassification of<br />

<strong>resources</strong> following the high gold prices. Submarginal demonstrated <strong>resources</strong> remained unchanged<br />

at 107 t, over half of which is in Western <strong>Australia</strong>.<br />

Inferred <strong>resources</strong> rose by 1 125 t due principally to the release of new data for inferred <strong>resources</strong> at<br />

the Olympic Dam (SA) and Bendigo (Vic) deposits. These, together with increases in all other areas<br />

except Tasmania and the Northern Territory caused the major growth. Western <strong>Australia</strong> continued to<br />

dominate inferred <strong>resources</strong> accounting for about 43% of total inferred <strong>resources</strong>.<br />

The ratio of demonstrated to inferred <strong>resources</strong> fell sharply from 2.4:1 in 2003 to 1.7:1 in 2004.<br />

This is a substantial improvement on the position in 2003 and indicates the availability of inferred<br />

<strong>resources</strong>, which may be upgraded by future exploration to the potentially mineable categories, has<br />

improved. However, much of the growth in inferred resource came from one deposit, which suggests<br />

that there is still a significant need to increase the level of inferred <strong>resources</strong> through discoveries.<br />

32<br />

Accessible EDR<br />

EDR for gold are essentially unencumbered (less than 1% is in any form of restricted area). At <strong>Australia</strong>’s<br />

2004 rate of production, EDR is sufficient for an average 22 years production. If, however, <strong>resources</strong><br />

only classified as reserves under the JORC Code are considered, they will support only 12 years<br />

at the 2004 production rate. This is similar to the 2003 reserve:production ratio. It should be<br />

remembered that these are average figures and that there are some operations that may continue<br />

after the 22 or 12 year periods and there are others that will close before the end of those periods.<br />

These figures continue to highlight the need for ongoing successful exploration in both the short<br />

and medium terms.<br />

JORC Reserves<br />

EDR is the sum of the JORC Code reserves categories plus those <strong>resources</strong> from the measured and<br />

indicated resource categories assessed by <strong>Geoscience</strong> <strong>Australia</strong> as likely to be economic. In 2004 just<br />

under 60% of EDR fell into the JORC reserves category compared to 64% in 2003.<br />

Exploration<br />

Gold dominated exploration spending (50.5%) and, at $397.1 million, was at its highest level since<br />

1998–99. Although in constant 2003–04 dollars, gold remained the dominant commodity sort,<br />

the level of spending grew only slightly and was less than in 2000–01 and less than half both the<br />

1996–97 level and the 1987–88 peak.

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