Eucalyptus trees in the Kalgoorlie region of Western Australia are drawing up gold particles from the earth via their root system and depositing it their leaves and branches. Scientists from CSIRO made the discovery and have published their findings in the journal Nature Communications. "The eucalypt acts as a hydraulic pump – its roots extend tens of metres into the ground and draw up water containing the gold. As the gold is likely to be toxic to the plant, it’s moved to the leaves and branches where it can be released or shed to the ground," CSIRO geochemist Dr Mel Lintern said. The discovery is unlikely to start an old-time gold rush – the "nuggets" are about one-fifth the diameter of a human hair. However, it could provide a golden opportunity for mineral exploration, as the leaves or soil underneath the trees could indicate gold ore deposits buried up to tens of metres underground and under sediments that are up to 60 million years old. "The leaves could be used in combination with other tools as a more cost effective and environmentally friendly exploration technique," Dr Lintern said. "By sampling and analysing vegetation for traces of minerals, we may get an idea of what’s happening below the surface without the need to drill. It’s a more targeted way of searching for minerals that reduces costs and impact on the environment. Gum leaf samples showing traces of manganese. "Eucalyptus trees are so common that this technique could be widely applied across Australia. It could also be used to find other metals such as zinc and copper." Using CSIRO’s Maia detector for x-ray elemental imaging at the Australian Synchrotron, the research team was able to locate and see the gold in the leaves. The Synchrotron produced images depicting the gold, which would otherwise have been untraceable. "Our advanced x-ray imaging enabled the researchers to examine the leaves and produce clear images of the traces of gold and other metals, nestled within their structure," principal scientist at the Australian Synchrotron Dr David Paterson said. "Before enthusiasts rush to prospect this gold from the trees or even the leaf litter, you need to know that these are tiny nuggets, which are about one-fifth the diameter of a human hair and generally invisible by other techniques and equipment." CSIRO research using natural materials, such as calcrete and laterite in soils, for mineral exploration has led to many successful ore deposit discoveries in regional Australia. The outcomes of the research provide a direct boost to the national economy. Access the full paper at Nature Communications [external link], Contacts and sources: Emily Lehmann, CSIRO Australia, Source: Nano Patents And Innovations
Gold Grows In Trees In Australia, Leaves Rich In Little Gold Nuggest
Arctic Current Flowed Under Deep Freeze Of Last Ice Age, Study Says
During the last ice age, when thick ice covered the Arctic, many scientists assumed that the deep currents below that feed the North Atlantic Ocean and help drive global ocean currents slowed or even stopped. But in a new study in Nature, researchers show that the deep Arctic Ocean has been churning briskly for the last 35,000 years, through the chill of the last ice age and warmth of modern times, suggesting that at least one arm of the system of global ocean currents that move heat around the planet has behaved similarly under vastly Credit: National Snow & Ice Data Center different climates. Arctic sea ice formation feeds global ocean circulation. New evidence suggests that this dynamic process persisted through the last ice age. "The Arctic Ocean must have been flushed at approximately the same rate it is today regardless of how different things were at the surface," said study co-author Jerry McManus, a geochemist at Columbia University's Lamont-Doherty Earth Observatory. Researchers reconstructed Arctic circulation through deep time by measuring radioactive trace elements buried in sediments on the Arctic seafloor. Uranium eroded from the continents and delivered to the ocean by rivers, decays into sister elements thorium and protactinium. Thorium and protactinium eventually attach to particles falling through the water and wind up in mud at the bottom. By comparing expected ratios of thorium and protactinium in those ocean sediments to observed amounts, the authors showed that protactinium was being swept out of the Arctic before it could settle to the ocean bottom. From the amount of missing protactinium, scientists can infer how quickly the overlying water must have been flushed at the time the sediments were accumulating. "The water couldn't have been stagnant, because we see the export of protactinium," said the study's lead author, Sharon Hoffmann, a geochemist at Lamont-Doherty. The upper part of the modern Arctic Ocean is flushed by North Atlantic currents while the Arctic's deep basins are flushed by salty currents formed during sea ice formation at the surface. "The study shows that both mechanisms must have been active from the height of glaciation until now," said Robert Newton, an oceanographer at Lamont-Doherty who was not involved in the research. "There must have been significant melt-back of sea ice each summer even at the height of the last ice age to have sea ice formation on the shelves each year. This will be a surprise to many Arctic researchers who believe deep water formation shuts down during glaciations." The researchers analyzed sediment cores collected during the U.S.-Canada Arctic Ocean Section cruise in 1994, a major Arctic research expedition that involved several Lamont-Doherty scientists. In each location, the cores showed that protactinium has been lower than expected for at least the past 35,000 years. By sampling cores from a range of depths, including the bottom of the Arctic deep basins, the researchers show that even the deepest waters were being flushed out at about the same rate as in the modern Arctic. The only deep exit from the Arctic is through Fram Strait, which divides Greenland and Norway's Svalbard islands. The deep waters of the modern Arctic flow into the North Atlantic via the Nordic seas, contributing up to 40 percent of the water that becomes North Atlantic Deep Water—known as the "ocean's lungs" for delivering oxygen and salt to the rest of world's oceans. One direction for future research is to find out where the missing Arctic protactinium of the past ended up. "It's somewhere," said McManus. "All the protactinium in the ocean is buried in ocean sediments. If it's not buried in one place, it's buried in another. Our evidence suggests it's leaving the Arctic but we think it's unlikely to get very far before being removed." Other authors are William Curry, president and director of Bermuda Institute of Ocean Sciences and emeritus scientist at Woods Hole Oceanographic Institution, and L. Susan Brown-Leger, a retired Woods Hole researcher. Contacts and sources: Kim Martineau, The Earth Institute at Columbia University, Image Link: Flickr, Source: Nano Patents And Innovations
Earth's Giant Hole
National Geographic Channel Presents: Earth's Giant Hole, Summary: Professor Darryl Granger, explores China's tiankengs -- giant natural holes, hundreds of metres deep, which have developed in unusual environmental conditions, Press Below Image Button To watch
Dark Materials in Vesta's Southern Hemisphere
This map shows the distribution of dark materials throughout the southern hemisphere of the giant asteroid Vesta. The circles, diamonds, and stars show where the dark material appears in craters, spots and topographic highs. The dashed line depicts the rim of the Veneneia basin, the black line the rim of the younger Rheasilvia basin. The red and white indicate high topography and blue and violet indicate low topography. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA, Note: For more information, see Picture This: Vesta's Dark Materials in Dawn's View.Source: Minex
Bison Return To The Wild: finding mankind's balance with nature
There is no greater image that represents the Great Plains of the United States as the wild bison or buffalo. However, that iconic symbol is an emblem of a long ago past when massive herds of bisonroamed free, when nature had not yet felt the sting of industrialized society. By the late 1800's only a few dozen wild bison existed, the majority - in the tens of thousands - having been wiped out to meet the demand for their hide. The nomadic Native American Indians that depended on these herds for meat, clothing, and shelter found the foundation of their lifestyle crippled with the loss of the bison. Their ability to live in harmony with nature was in jeopardy as traders and settlers from the east encroached on their lands. A culture was being undermined and cast to the winds. In March, the Fort Peck Indian Reservation in Montana received 61 genetically pure wild bison from one of the last remaining herds in Yellowstone National Park. The transfer was many years in the making, with additional pressure being exerted on Montana state agencies by the Defenders of Wildlife, a conservation organization that focuses on many threatened wild species in the U.S. like bison and wolves. The bison will run free within the reservation's over 7,000 acre reserve. There is an ecological significance to the expansion of territory for this once prevalent species. But the cultural significance is probably of greater import. Bison are grazers and as such they kept prairie food supplies and the animal populations that depended on that grassland in check. Occasionally a juvenile bison might be prey to wolves. However, in today's world of bred cattle and urbanization, the extinction of the bison would probably not have any serious ecological consequences - not like the loss of, say, wolves which help control the deer and, in particular, the small varmint and rodent populations. It is on a cultural level that the return of the bison has tremendous resonance. Again, the bison is an iconic image of a lifestyle in harmony with nature, a reminder of a time before the loss of innocence to the forces of progress of western civilization. “These majestic animals have played a very significant part in the history, religion and culture of our native people of the Fort Peck Reservation. These bison have sustained our ancestors for thousands of years and they are in need of us returning the favor. We are here to make sure they will always be here for our children," told Floyd Azure, Fort Peck Reservation Tribal Council Chairman to the Associated Press.That same attitude regarding mankind's role in the fabric of nature, that interaction and interdependency, can be found in other cultures, particularly with island nations and their relationship with the sea. From Hawaii to the South Pacific to Malaysia and beyond, their histories are culturally intertwined with the oceans and the animals that live within. It is a spiritual relationship that impacts their entire way of life. "Civilized" industrialized man has chosen technology as its spiritual guru and while it has certainly improved the material quality of life, there is a price that we are now learning which must be paid. All of the environmental issues we face today have their fundamental root cause in this greater devotion to technology over that of nature. What to do? Well, we're not ready to give up our cars, flat screens, and cell phones for teepees and buckskin. However, we can learn from these nature-bound cultures as to how to strike a new balance, to redefine "in harmony with nature" in a manner that meets our needs while protecting our natural resources. Conservation should not be viewed as a form of sacrifice or denial. It should be seen as a means to preserve what we have so that we can responsibly continue to prosper in what we are realizing is a finite world. Source: RTSea
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