SBS > Gold > Environment > The mining mistakes of a golden history


The mining mistakes of a golden history


The Birth of a Golden Age

Between three hundred and five hundred million years ago, the land that is now called Australia underwent a dramatic geological transformation. Once covered by the great prehistoric Ordovician and Silurian Seas, vast masses of land were thrown to the surface as powerful forces fractured, collapsed and folded the earth upon itself. This land became part of Gondwana, a giant continent of mountains, rivers and explosive volcanoes. As part of this transaction, hot water circulated amongst fissures of rock and reef, which, in turn, produced veins of gold in the bedded rock. After millions of years of erosion and earth movement, most of this hard rock weathered into clay, allowing streams to form through gullies in the highlands. As the land continued to form, gold was carried down into streams and riverbeds that sometimes hardened into hillsides.


Hiscocks Gully by Archibald Vincent Smith
Courtesy of the La Trobe Collection
State Library of Victoria
H1771



The Evolution of Pollution

Prior to the 1850’s, most of the Australian continent had remained relatively free from human intervention. With the discovery of gold, however, that was all about to change. Even in its early stages, when mining was a primitive exercise of panning, cradling and sifting, natural ecosystems were being permanently altered. As mining towns developed, land had to be cleared to accommodate the roads, telegraphs and railways that were a sign of progress. And as this progress continued, a new demand for timber grew in earnest. As a result, woodcutters pushed further and further into Australian forests to support the burgeoning demands of thriving mining communities. And as these communities evolved into small towns, water supplies were needed to support the sanitary requirements of their inhabitants. As such, local creeks and river systems were diverted, dammed and irreparably changed.

As mining operations became more sophisticated, demands on natural resources grew in accordance. By the late 1850’s, there was a sentiment that most of the gold hidden close to the earth’s surface had already been discovered by early prospectors. Shaft mining enterprises now needed to be developed in order to extract gold from quartz deposits hidden far beneath the earth’s surface. Already, early gold mining communities had ravaged most local ecosystems. More modernized gold mining companies threatened to extend the reach of this devastation by employing teams of woodcutters to sweep out into forests in order to feed the demand of new mining machines.

Water was also becoming an increasingly valuable commodity. New technologies demanded more sophisticate washing procedures to extract gold from quartz. Steam engines were being harnessed as a popular form of power, and, in some cases, water wheels were being driven. All of these technologies required a water supply far greater than the dams and channels that had been previously used for sanitation. Unfortunately, however, the task of supplying enough water in areas of erratic rainfall was not simple. Drought was a problem that carried with it real financial consequences. And so, artificial sources of water were created, and a great number of Australia’s water systems became laced with channels and sluices, diverting water into mining catchments and dams.


Sluicing Plant, showing Hydraulic Nozzle at work, Castlemaine
Courtesy of the La Trobe Collection
State Library of Victoria
H90.140/667


Towards the end of the nineteenth century, hydraulic mining (otherwise known as sluicing) technologies devastated local ecosystems to such an extent that the first whispers of environmental protest began to ruminate. Vast quantities of high-pressured water were blasted into hills and along creek beds in an attempt to wash gold and soil into catchment areas. Once isolated, the silt could then be filtered for gold, whilst the extract sludge was dumped back into the blasted creek or riverbed. Another popular mining technique that was used at this time was Dredging. Firstly, this technique required natural river systems to be diverted and cut off, so that riverbanks and their bottoms could be literally scraped clean. The dredging vessels would then move slowly along natural water systems, hauling soil to the surface to be chemically treated, rinsed and sifted for gold. Waste soil was then dumped back onto the riverbank or dumped behind the dredge.


The Environmental Equation

At the time, these particularly devastating methods of mining caused murmurs of protest from farmers and pastoralists who could see for themselves the damage that was being inflicted upon their local ecology. Eventually, these mining methods were outlawed by governments, but not before vast areas of natural forest had disintegrated into wasteland. The most infamous example of mining damage in Australia occurs at the Queenstown region of Western Tasmania. Once a verdant expanse of mountainous rainforest and plentiful waterways, the area has now been transformed into a treeless desert of silt, sediment and ecological decay. Big open cuts channel into its topography, thousands of tones of mullock sits upon the surface of the land and the Queens River, once stained brown from the tannin of native gums, is now clogged full of chemically poisoned top soil, washed away by heavy rains.

The effects of this type of environmental damage are irreversible. Once trees are cut down, topsoil erodes away. When silt is dumped into waterways, it devastates every nexus of life in that ecosystem. Today, huge volumes of silt are still being carried slowly downstream, until they reach the sea and impact marine environments. Indeed, the mining mistakes that were made in the past century will still be felt by the Australian environment for decades yet to come.


Credits

By James Cowie

References:

Don Garden, Catalyst or Cataclysm? Gold Mining and the Environment, Victorian Historical Journal Vol 72, No 1-2, September 2001.

John Berchervaise, Rediscovering Victoria’s Goldfields, 1980.



 
 

| Top | Home  | About the VCC  | Contact us |