EARLY THEORIES AND PRACTICALITIES ON GOLD OCCURRENCE IN AUSTRALIA

The discovery of gold in Australia forced many changes to theory on the occurrence and origin of gold deposits. Initial discoveries appeared to confirm existing ideas on the global distribution of gold-bearing terrains. Later discoveries and research would show that this confirmation was largely coincidental, but nevertheless helpful in early prospecting. Prior to the first Australian gold rush, theoretical predictions of payable gold were made by Sir Roderick Murchison and Rev. W. B. Clarke based on knowledge of accidental gold finds and geological analogy with known areas of significant gold occurrence, particularly the Ural region in Russia. These predictions were overwhelmed when Edward Hargraves, realised he might be able to spark a gold rush that would prove the existence of payable gold. Hargraves travelled to the Bathurst region of New South Wales where numerous gold finds had already been made and with local guides, prospected Lewis Ponds Creek and the Macquarie River. He demonstrated the methods of alluvial mining, to John Lister and William and James Tom enabling them to find sufficient alluvial gold to initiate a gold rush. The crowd of attracted diggers demonstrated the existence of a payable goldfield. The unstoppable first rush resulted in the pragmatic introduction of government regulation and administration to allow alluvial gold mining. Other discoveries of payable goldfields quickly followed. As the local scientific expert on gold, W. B. Clarke was commissioned to conduct two extensive surveys of the goldfields between 1851 and 1853. Clarke also drew on his geological knowledge to provide practical advice to the thousands of prospecting gold diggers. Gold-bearing quartz reefs and lodes were discovered, but it was predicted that these could not be mined economically. Theory also predicted that the reef gold would not continue to depth. Practical observations and mining experience from the numerous discoveries led to revision of the widely held dicta on gold occurrence. Alluvial gold was found in a range of settings, including the recent drainage and ancient and buried leads. A wider variety of rock types was recognised as favourable for gold. Different styles of reef gold were identified and found to be economically mineable to great depth. Evolving ideas on the origin of gold deposits were widely discussed, tested, and refined. Of the many players involved in the early discovery of gold in Australia, Clarke, Hargraves and Murchison probably had the greatest overall influence in terms of theoretical predication and practical outcomes that initiated the Australian gold-mining industry.