![]() ![]() This misshapen diamond discard, only 3 mm across, contains an even smaller bit of ringwoodite (as indicated), the first terrestrial sample ever discovered. ![]() The discovery confirms a couple of theories about the composition of earth’s mantle. Just finding a natural terrestrial sample of ringwoodite was a landmark event, but even more momentous is the discovery that it contains about 1.5 weight% water. “It's so small, this inclusion, it's extremely difficult to find, never mind work on, so it was a bit of a piece of luck, this discovery, as are many scientific discoveries,” 2 says Graham Pearson, Canadian geochemist and lead author of the study published in Nature. In the stone lurked a ringwoodite inclusion. With no commercial value, geochemists looking for a way to date diamonds purchased it from miners in the Juína region of Mato Grosso, Brazil. The tiny treasure that has given us a peek into the earth’s deep secrets is enclosed in a misshapen brownish diamond only 3 millimeters in diameter. 1ĭiscard-grade diamonds, formed where it’s much too deep to drill, are gems to geologists wishing to probe conditions deep in the earth. The crystalline structure of ringwoodite could theoretically accommodate up to 2% water by weight. There is room between the atoms in this crystal lattice for a significant amount of water. Until now, ringwoodite existed only in laboratories and in some meteorites thought to have been pelted with enough pressure to force the crystalline structure of olivine to assume an octahedral configuration known as a spinel structure. What is ringwoodite? Certainly not a mineral found in anyone’s ordinary rock collection! Ringwoodite is an alternate crystalline form (a polymorph) of the mineral olivine-(Mg 2+) 2(SiO 4). Analysis of a diamond volcanically coughed up from deep in the earth and recovered in Brazilian river gravel has serendipitously revealed water-containing ringwoodite, a testimony to the presence of both water and the elusive olivine polymorph under the earth. More than just a place of molten rock, earth’s mantle apparently harbors a watery zone able to hold an ocean of water. FOX News: “ Rare Diamond Reveals Earth’s Interior Is All Wet”.This story was originally published on Nov. 4, 9:55 p.m.: This story has been updated with quotes and information from Temple University biologist Erik Cordes. It’s more than the ‘rigged’ election’: Voters across the political spectrum believe in conspiracy theoriesĬhimpanzees need friends too - their stress levels show itĪccepting more Facebook friend requests is linked to lower mortality, study says “It could be a few kilometers down under the seafloor.”įollow me on Twitter seangreene89 and “like” Los Angeles Times Science on Facebook. ![]() ![]() “Since the source of the brine and hydrocarbons is basically a crack in the Earth, it is tough to find the bottom,” Cordes said. The probe plunged more than 62 feet into the brine pool but never reached the bottom. At that depth, the Gulf of Mexico is about 40 degrees.Īs the sensor sank deeper, the temperature rose further, to 66 degrees. From the lake’s surface to a depth of about 10 feet, the brine was a relatively warm 46 degrees Fahrenheit. To measure the pool’s salinity, temperature and depth, the Hercules lowered a sensor down into the pool. Mussels living on the edge of the lake help keep its outer walls intact. I think that’s what’s captured people’s imaginations. “You don’t expect to see in the muddy background of the deep sea,” Cordes said. The body of water, which they also refer to as the “Hot Tub Brine Machine,” is a crater-like pool that rises 12 feet above the ocean floor, surrounded by bright red and white mineral deposits. The brine then pools into underwater lakes, rivers and “spectacular” waterfalls, the scientists wrote. The result is a super-salty brine so dense it doesn’t easily mix with the seawater around it. Under the weight of these sediments, the salt layers shift and crack the shale above, allowing oil, gas and brine to escape. Over time, the salt layers became submerged and buried. These underwater lakes formed over millions of years as a much shallower Gulf of Mexico evaporated and left behind massive beds of salt. ![]()
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