[meteorite-list] A Piece Of The Heavens
From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:43:31 2004 Message-ID: <200107121523.IAA11632_at_zagami.jpl.nasa.gov> http://www.hamiltonspectator.com/news/435248.html A piece of the heavens By Kate Barlow The Hamilton Spectator July 5, 2001 Joseph Mahe was busy clearing his fields of stones forced to the surface during the spring thaw when he came upon a large, rust-coloured rock. His first thought, that morning in 1999, was of the damage it could do to his farm machinery. "But when I got hold of it, it was much heavier than an ordinary rock," the farmer recalls. "I thought this is something different." Joseph and his wife Marcelle often came across interesting rocks, enough that Joseph has earned the nickname Fred -- as in Flintstone. In the 34 years on their Hagersville farm, they have uncovered arrowheads and fossils by the score. But never anything like this. Joseph tossed the strangely heavy rock onto his tractor, finished his stone clearing and returned to the barn where he called a neighbour. They took a hammer to the rock. It bounced off. The rock made a dull metallic sound. The two hit it again, and again. Eventually, metal showed through the surface. Perhaps it was a piece of farm machinery from years past. The neighbour joked that Christopher Columbus must have dropped it when he passed by. But Marcelle, on her return from grocery shopping, declared, "That's a meteorite!" The previous winter, Marcelle had read a book on the minerals of her home region of Brittany, France. One of the illustrations of a meteorite looked just like the rock her husband and neighbour were puzzling over. "Let's just say they were skeptical," says Marcelle tactfully of the men's reaction. But they couldn't come up with a better theory, so they sought advice from a relative who had been a mineral collector since boyhood. He felt the chances that it was some kind of meteorite were high enough to consult an expert. The family arranged to take the 30-kilogram specimen to the 1999 Rockhound Gemboree, Canada's largest mineral and gem show, held every August in Bancroft. They will never forget the excited expression on Richard Herd's face, as the curator of Canada's National Meteorite Collection bent to examine the Mahes' rock. He didn't give them a definitive answer, but said he felt it could be a meteorite and that he would make arrangements to have it tested. "We were all pretty excited," says daughter Michelle Holmes. "You can go to a (mineral) show and buy them, but how often can you say I found a meteorite?" Before Herd actually saw the Mahes' find, he was skeptical. Many people approach him with a rock they believe is a meteorite. "Nine hundred and ninety-nine times out of 1,000, it's not," he says. "But when I tried to lift (the Mahes' find), I thought, it's entirely possible it is one. It looked good, the colour looked good and it was magnetic." He got permission from the Mahes to take the rock back to Ottawa where it was photographed and a small piece removed before it was returned to them the following year. Steve Kissin, a geology professor at Thunder Bay's Lakehead University, learned of the Hagersville meteorite in the fall of 1999 at a meeting of the Canadian Space Agency's Meteorites and Impacts Advisory Committee and was later sent two small slices cut from the rock. Kissin's first task was to wash the pieces with an acid solution so that, when viewed under a specially designed microscope, he could detect kamacite and taenite, two forms of iron present in meteorites but rare on earth. The acid test of authenticity was spotting tiny crystals known as Schreibersite. Their distinctive structure and pattern proved beyond doubt that the slices of metal were from outer space. Kissin also observed bands called Neumann lines, indicative of the cosmic shock following a collision by the meteorite's parent body. "That's not something found in terrestrial rocks, but which is quite common in meteorites," said Kissen. The professor's final test, before the samples were dispatched south to Activation Laboratories of Ancaster for detailed analysis, was to measure the hardness of the metal to determine the degree of cosmic shock and prepare two "standards" to measure the Hagersville samples against, one of steel and another from a well-known meteorite. Activation Laboratories has laboratories in the United States and South America and customers in 60 countries. It has a worldwide reputation for chemical, physical and metallurgical analysis of everything from meteorites and mining exploration samples to fire debris and failure analysis for the aircraft and automobile industries. The company's client list reads like a Who's Who of the global mining community. It has helped discover copper in Chile, diamonds in the Northwest Territories and gold in Mexico. Its labs can take a leaf from a tree and tell you what's in the ground below. Its patented technology can analyse a soil sample and detect what lies 400 metres below the surface. "We're leaders in the world in fine analysis," says company founder and owner Eric Hoffman. A meteorite sample is placed first in a plastic capsule and made radioactive in McMaster University's nuclear reactor before returning to the company's laboratories for what's called instrumental neutron activation analysis. This involves placing the sample in what's called a germanium detector -- resembling a large barbecue propane tank -- which measures the presence and quantity of 13 different minerals. The proportion of those elements will determine the kind of meteorite. The sample is then disposed of at Canada's nuclear laboratories at Chalk River. Once the Ancaster analysis was completed, the results were sent to Kissin. He decides whether a meteorite is a new find, part of another meteorite, or one that has been transported from its original site. After completing his analysis, Kissin must submit his results and the proposed name to that august body, The Meteoritical Society, formed in 1933 to promote the study of extraterrestrial materials and their history. The Mahes haven't decided what they will do with their meteorite -- sell it, donate it to the national rock collection or keep it as a keepsake. The value of a meteorite depends on how unusual it is, but starts at $1 a gram. For now it is kept under lock and key in a safe place, far from the farm where it lay, perhaps since the world was young. "This is out of this world," says Marcelle. You can contact Kate Barlow by e-mail at kbarlow_at_hamiltonspectator.com or by telephone at 905-526-3408. IMAGE CAPTION: Marcelle and Joseph Mahe of Hagersville show off their 30-kilogram meteorite found on their farm. Photo: Kaz Novak, the Hamilton Spectator Received on Thu 12 Jul 2001 11:23:13 AM PDT |
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