Wednesday, October 23, 2013

Pure Luck? Where you still find gold - NEWS

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 well bekomms: The highest gold concentration, the researchers found in the leaves of eucalyptus trees. Well bekomms: The highest gold concentration, the researchers found in the leaves of eucalyptus trees (photo: Arnaud Gaillard / Wikipedia / CC BY-SA 1.0).

Wednesday 23 October 2013

Not only in China, the demand for raw materials and precious ores is growing immensely. Of new reserves is intensively sought. Scientists are in the process comes to a startling realization: gold grows on trees. Almost.

It’s an unusual discovery: Ironically, in eucalyptus, Australian researchers have discovered tiny particles of gold. How they get there, was quickly resolved for the scientists: Probably the gold particles were sucked out of the trees from the ground and pumped up so geochemist Melvyn Lintern, one of the authors of the study. “The eucalyptus acts as a hydraulic pump.”

The scientists of the Commonwealth research organization CSIRO made their discovery in the resource-rich region of Kalgoorlie in Western Australia, where in the late 19th Century was a major gold rush. The gold stored there 35 feet below ground. For the far-reaching roots into the depths of the eucalyptus trees that is a reachable distance.

much narrower than a human hair

The scientists reported particles using X-ray images in leaves, branches and bark after. The highest concentration they found in the leaves. Since the gold is probably toxic to the plant, it will probably be forwarded to the outermost extremities, thus minimize harmful biochemical reactions could take place, the researchers explain.

The Witwatersrand goldfield in South Africa is the largest deposit in the world. More than 40,000 tons of gold it has delivered, tens of thousands of tons are still available. however, they are so deep (almost 4000 meters) that their removal is economically only at high gold prices. is the Witwatersrand goldfield in South Africa the world’s largest deposit. More than 40,000 tons of gold it has delivered, tens of thousands of tons are still available. However, they are so deep (almost 4000 meters) that their removal is economically only at high gold prices (photo: imago stock & people).

According to the authors of the study, published in the journal “Nature Communications”, the gold leaves will probably cause hardly a new gold rush: the particles found in the trees were only one-fifth the width of human hair – and only on the high developed X-ray images visible. Keep their findings, the researchers nevertheless useful. For the investigation of the mineral content in the plants with this method can provide information on minerals under the ground. In addition to gold as could be demonstrated zinc or copper. Since so no expensive holes were needed would cost saving and protects the environment, Lintern.

volcanic zones are interesting

Worldwide researchers are busy trying to discover large deposits of valuable metals. But such a fund still has a lot to do with luck. Only about one in a thousand studied geological formations, it is worthwhile to build a mine conveyor. Therefore, geologists are increasingly concerned with the mechanisms that give rise to huge deposits of copper, gold, silver, platinum and other metals, but also of diamonds.

play an important role as so-called subduction zones. These are areas where one tectonic plate dives under another, and gradually melted in the hot mantle. In these areas there are very frequently active volcanoes and also large deposits of volcanic rock. More recent findings on these areas has important mechanisms filtered Jamie J. Wilkinson of Imperial College London, which can lead to the formation of giant ore deposits. “Volcanic mineral deposits are the source of large quantities of copper, molybdenum, gold and silver, which are used by people,” said Wilkinson in the journal “Nature Geoscience.” It is the underground magma chambers and the surrounding rock, which accumulate gradually by certain chemical and physical processes metals.

In order to mine 1 gram of fine gold (center), a prospector had here about 50 tons (2 dumper truck) river sediments with his wash sand pan. to mine / To 1 gram of fine gold ( center), had here a prospector around 50 tonnes (2 dumper truck) Wash with its sandy river sediments pan (Photo:. picture-alliance / dpa)

The course takes time. For copper, molybdenum and gold deposits in volcanic rocks, it takes 700,000 years, until a huge deposit of ore is obtained. When is a huge reserve, Jeremy P. Richards of the University of Alberta in Canada if it includes more than 100 tons of gold, or more than two million tons of copper. Depending on the definition, however, up to three times higher numbers would be called, says Richards.

earthquake lead to metal enrichment

The scientists also looked huge gold and silver deposits, which are not necessarily due to volcanic activity. These mineral deposits from fluids at temperatures between 200 and 100 degrees earthquakes play an important role for high metal concentrations. The resulting gaps in quake rocks fill up quickly with water, which evaporates and draws more water from the rock. To accumulate in the gap at the metals dissolved in the water.

taking a different approach, researchers William L. Griffin, Suzanne Y. and GC Begg O’Reilly from Macquarie University in Australia. They advocate involving the entire lithosphere (crust and uppermost part of the mantle) models to the formation of ores. The lithosphere “plays a significant role in the formation of ore from magma,” said the researchers. You propose to explore that part of the mantle, which is part of the lithosphere beneath continents on structure, age and composition and recorded on maps. The geological model could then provide guidance on suitable places for exploring large, metal-rich ore deposits. – This method has the good fortune



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