 |
 |
 |
 |
 |
 |
 |
 |
 |
|
|
. |
Geologists Point To Outer Space As Source Of The Earth's Mineral Riches
Toronto, Canada (SPX) Oct 26, 2009 According to a new study by geologists at the University of Toronto and the University of Maryland, the wealth of some minerals that lie in the rock beneath the Earth's surface may be extraterrestrial in origin. "The extreme temperature at which the Earth's core formed more than four billion years ago would have completely stripped any precious metals from the rocky crust and deposited them in the core," says James Brenan of the Department of Geology at the University of Toronto and co-author of the study published in Nature Geoscience on October 18. "So, the next question is why are there detectable, even mineable, concentrations of precious metals such as platinum and rhodium in the rock portion of the Earth today? Our results indicate that they could not have ended up there by any known internal process, and instead must have been added back, likely by a 'rain' of extraterrestrial debris, such as comets and meteorites." Geologists have long speculated that four and a half billion years ago, the Earth was a cold mass of rock mixed with iron metal which was melted by the heat generated from the impact of massive planet-sized objects, allowing the iron to separate from the rock and form the Earth's core. Brenan and colleague William McDonough of the University of Maryland recreated the extreme pressure and temperature of this process, subjecting a similar mixture to temperatures above 2,000 degrees Celsius, and measured the composition of the resulting rock and iron. Because the rock became void of the metal in the process, the scientists speculate that the same would have occurred when the Earth was formed, and that some sort of external source - such as a rain of extraterrestrial material - contributed to the presence of some precious metals in Earth's outer rocky portion today. "The notion of extraterrestrial rain my also explain another mystery, which is how the rock portion of the Earth came to have hydrogen, carbon and phosphorous - the essential components for life, which were likely lost during Earth's violent beginning." Share This Article With Planet Earth
Related Links University of Toronto Dirt, rocks and all the stuff we stand on firmly
Coastal erosion threatens Goa's idyllic beachesPanaji, India (AFP) Aug 30, 2009 India's resort state of Goa has been hit by several setbacks in the last 18 months, including high-profile crime and the knock-on effects of Islamist extremist attacks up the coast in Mumbai. But with each holiday season, a greater threat to the tourist trade emerges -- coastal erosion that is leading to fears that some of the former Portuguese colony's famous white sandy beaches could ... read more |
. |
|
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2009 - SpaceDaily. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement |
del.icio.us
Digg
Reddit
YahooMyWeb
Google
Facebook