Becky Oskin, Writer at OurAmazingPlanet
California : Earthquakes have the Midas touch. The
flow of water that evaporates during earthquakes has been precipitated
gold, according to the model, published in the journal "Nature
Geoscience" issue of March 17.
The model shows quantitative mechanisms related to the relationship between gold and quartz are visible in many gold deposits in the world, said Dion Weatherley, a geophysicist from the University of Queensland in Australia and lead author of the study.
When the earthquake occurred, the event moves shards on the ground - called a fault or fracture fault. Faults that can cause a small fractures along the shift, associated with allusions that appear as a square gap. Water frequently lubricate the cracks, filling fractures and allusion.
About 10 kilometers below sea level, temperature and under tremendous pressure, water carrying carbon dioxide, silica and economically attractive elements like gold are highly concentrated.
The model shows quantitative mechanisms related to the relationship between gold and quartz are visible in many gold deposits in the world, said Dion Weatherley, a geophysicist from the University of Queensland in Australia and lead author of the study.
When the earthquake occurred, the event moves shards on the ground - called a fault or fracture fault. Faults that can cause a small fractures along the shift, associated with allusions that appear as a square gap. Water frequently lubricate the cracks, filling fractures and allusion.
About 10 kilometers below sea level, temperature and under tremendous pressure, water carrying carbon dioxide, silica and economically attractive elements like gold are highly concentrated.
Shock, Vibration, and Gold
During the earthquake, cracks suddenly wide open. Like
taking the lid of the appliance to cook some rice. Water evaporates in the
gap, and turn it into steam and forces silica, which form the mineral
quartz, and gold come out in liquid form and headed to a nearby surface,
said Weatherley and co-author Richard Henley , from the Australian National University in Canberra.
Although scientists have long suspected that the sudden drop in pressure may explain the relationship between the giant gold deposits and ancient fault, the study adapted the idea into more extreme, said Jamie Wilkinson, geochemist at Imperial College London in the UK, who was not involved in the research it.
"To me, it seems pretty reasonable. It is something that people want to make it as a model, both experimentally and numerically," said Wilkinson told OurAmazingPlanet.
Previously, scientists assumed the liquid will effervesce, bubbling like soda bottles are opened, during an earthquake or other pressure changes. The event will fill the bags with gold underground. Other researchers said the minerals will only accumulate slowly over time.
Weatherley said the amount of gold that is left after the earthquake is very small, because the fluid underground at most only carry one part per million of the precious element. But the Alpine Fault earthquake zone like New Zealand, one of the fastest in the world, can build a gold deposit that could be mined in 100 thousand years, he said.
Surprisingly, quartz does not even have time to crystallize, according to the indications of the study. Conversely, minerals out of the liquid in the form of nanoparticles, maybe even make a gel-like substance on the wall fracture. Nanoparticles quartz then crystallized from time to time.
Even earthquake of magnitude smaller than the 4.0 SR, which resulted in vibration but rarely cause damage, can trigger instantaneous evaporation, according to research findings.
Although scientists have long suspected that the sudden drop in pressure may explain the relationship between the giant gold deposits and ancient fault, the study adapted the idea into more extreme, said Jamie Wilkinson, geochemist at Imperial College London in the UK, who was not involved in the research it.
"To me, it seems pretty reasonable. It is something that people want to make it as a model, both experimentally and numerically," said Wilkinson told OurAmazingPlanet.
Previously, scientists assumed the liquid will effervesce, bubbling like soda bottles are opened, during an earthquake or other pressure changes. The event will fill the bags with gold underground. Other researchers said the minerals will only accumulate slowly over time.
Weatherley said the amount of gold that is left after the earthquake is very small, because the fluid underground at most only carry one part per million of the precious element. But the Alpine Fault earthquake zone like New Zealand, one of the fastest in the world, can build a gold deposit that could be mined in 100 thousand years, he said.
Surprisingly, quartz does not even have time to crystallize, according to the indications of the study. Conversely, minerals out of the liquid in the form of nanoparticles, maybe even make a gel-like substance on the wall fracture. Nanoparticles quartz then crystallized from time to time.
Even earthquake of magnitude smaller than the 4.0 SR, which resulted in vibration but rarely cause damage, can trigger instantaneous evaporation, according to research findings.
These Hills Have Gold
Quartz associated with gold deposition connected with several well-known, such
as gold flakes that give rise to raid gold in the 19th century in
California and the Klondike. Both sediment eroded from the upstream quartz veins. Gold deposit consists of particles, flakes and lumps are mixed with sand and gravel in streams and riverbeds. The miners gravel traced to its source, that's where the hard rock mining continues to this day.
However, earthquakes are not the only natural events that can be a source of gold. Volcanoes and groundwater flow is also productive, or more productive, to produce precious metals. While Weatherley and Henley stated that the same process can take place under the volcano, Wilkinson, who studies volcanoes connected with gold, saying it was not proven.
"Under the volcano, most of the gold was not deposited within an active fault during the earthquake," said Wilkinson. "It was a very different mechanism."
Understanding how the formation of gold helped the company to define new mining sites. "Recent knowledge on the mechanisms of formation of gold deposits, gold exploration efforts could help in the future," said Weatherley.
However, earthquakes are not the only natural events that can be a source of gold. Volcanoes and groundwater flow is also productive, or more productive, to produce precious metals. While Weatherley and Henley stated that the same process can take place under the volcano, Wilkinson, who studies volcanoes connected with gold, saying it was not proven.
"Under the volcano, most of the gold was not deposited within an active fault during the earthquake," said Wilkinson. "It was a very different mechanism."
Understanding how the formation of gold helped the company to define new mining sites. "Recent knowledge on the mechanisms of formation of gold deposits, gold exploration efforts could help in the future," said Weatherley.
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