October 2020

Antarctica Yields Oldest Fossils of Giant Birds With 21-foot Wingspans

<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-nowTMBQQBd0/X5wo0xNiIMI/AAAAAAAASng/wJQQqf4uQxcrK1KgjqEQwGIi8Wx5TTpagCLcBGAsYHQ/s1200/Antarctica%2BYields%2BOldest%2BFossils%2Bof%2BGiant%2BBirds%2BWith%2B21-foot%2BWingspans%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="800" data-original-width="1200" height="426" src="https://1.bp.blogspot.com/-nowTMBQQBd0/X5wo0xNiIMI/AAAAAAAASng/wJQQqf4uQxcrK1KgjqEQwGIi8Wx5TTpagCLcBGAsYHQ/w640-h426/Antarctica%2BYields%2BOldest%2BFossils%2Bof%2BGiant%2BBirds%2BWith%2B21-foot%2BWingspans%2B%25281%2529.jpg" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">A paleontologist cleans a fossilized bird cranium at Peru’s National History Museum in Lima, Friday, Photo: Martin Mejia, Associated Press<br /></td></tr></tbody></table><br /><p style="text-align: left;">Fossils recovered from Antarctica in the 1980s represent the oldest giant members of an extinct group of birds that patrolled the southern oceans with wingspans of up to 21 feet that would dwarf the 11½-foot wingspan of today’s largest bird, the wandering albatross.<br /><br />Called pelagornithids, the birds filled a niche much like that of today’s albatrosses and traveled widely over Earth’s oceans for at least 60 million years. Though a much smaller pelagornithid fossil dates from 62 million years ago, one of the newly described fossils — a 50 million-year-old portion of a bird’s foot — shows that the larger pelagornithids arose just after life rebounded from the mass extinction 65 million years ago, when the relatives of birds, the dinosaurs, went extinct. A second pelagornithid fossil, part of a jaw bone, dates from about 40 million years ago.<br /><br />“Our fossil discovery, with its estimate of a 5-to-6-meter wingspan — nearly 20 feet — shows that birds evolved to a truly gigantic size relatively quickly after the extinction of the dinosaurs and ruled over the oceans for millions of years,” said Peter Kloess, a graduate student at the University of California, Berkeley.<br /><br />The last known pelagornithid is from 2.5 million years ago, a time of changing climate as Earth cooled, and the ice ages began.<br /><br />Kloess is the lead author of a paper describing the fossil that appears this week in the open access journal Scientific Reports. His co-authors are Ashley Poust of the San Diego Natural History Museum and Thomas Stidham of the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences in Beijing. Both Poust and Stidham received their Ph.Ds from UC Berkeley.<br /></p><h4 style="text-align: left;">Birds with pseudoteeth</h4><p style="text-align: left;">Pelagornithids are known as ‘bony-toothed’ birds because of the bony projections, or struts, on their jaws that resemble sharp-pointed teeth, though they are not true teeth, like those of humans and other mammals. The bony protrusions were covered by a horny material, keratin, which is like our fingernails. Called pseudoteeth, the struts helped the birds snag squid and fish from the sea as they soared for perhaps weeks at a time over much of Earth’s oceans.<br /><div style="width:100%;margin: 0px auto">
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</div><br />Large flying animals have periodically appeared on Earth, starting with the pterosaurs that flapped their leathery wings during the dinosaur era and reached wingspans of 33 feet. The pelagornithids came along to claim the wingspan record in the Cenozoic, after the mass extinction, and lived until about 2.5 million years ago. Around that same time, teratorns, now extinct, ruled the skies.<br /><br />The birds, related to vultures, “evolved wingspans close to what we see in these bony-toothed birds (pelagornithids),” said Poust. “However, in terms of time, teratorns come in second place with their giant size, having evolved 40 million years after these pelagornithids lived. The extreme, giant size of these extinct birds is unsurpassed in ocean habitats,””<br /><br />The fossils that the paleontologists describe are among many collected in the mid-1980s from Seymour Island, off the northernmost tip of the Antarctic Peninsula, by teams led by UC Riverside paleontologists. These finds were subsequently moved to the UC Museum of Paleontology at UC Berkeley.<br /><br />Kloess stumbled across the specimens while poking around the collections as a newly arrived graduate student in 2015. He had obtained his master’s degree from Cal State-Fullerton with a thesis on coastal marine birds of the Miocene era, between 17 million and 5 million years ago, that was based on specimens he found in museum collections, including those in the UCMP.<br /><br />“I love going to collections and just finding treasures there,” he said. “Somebody has called me a museum rat, and I take that as a badge of honor. I love scurrying around, finding things that people overlook.”<br /><br />Reviewing the original notes by former UC Riverside student Judd Case, now a professor at Eastern Washington University near Spokane, Kloess realized that the fossil foot bone — a so-called tarsometatarsus — came from an older geological formation than originally thought. That meant that the fossil was about 50 million years old instead of 40 million years old. It is the largest specimen known for the entire extinct group of pelagornithids.<br /><br />The other rediscovered fossil, the middle portion of the lower jaw, has parts of its pseudoteeth preserved; they would have been up to 3 cm (1 inch) tall when the bird was alive. The approximately 12-cm (5-inch-) long preserved section of jaw came from a very large skull that would have been up to 60 cm (2 feet) long. Using measurements of the size and spacing of those teeth and analytical comparisons to other fossils of pelagornithids, the authors are able to show that this fragment came from an individual bird as big, if not bigger, than the largest known skeletons of the bony-toothed bird group.<br /></p><h4 style="text-align: left;">A warm Antarctica was a bird playground</h4><p style="text-align: left;">Fifty million years ago, Antarctica had a much warmer climate during the time known as the Eocene and was not the forbidding, icy continent we know today, Stidham noted. Alongside extinct land mammals, like marsupials and distant relatives of sloths and anteaters, a diversity of Antarctic birds occupied the land, sea and air.<br /><br />The southern oceans were the playground for early penguin species, as well as extinct relatives of living ducks, ostriches, petrels and other bird groups, many of which lived on the islands of the Antarctic Peninsula. The new research documents that these extinct, predatory, large- and giant-sized bony-toothed birds were part of the Antarctic ecosystem for over 10 million years, flying side-by-side over the heads of swimming penguins.<br /><br />“In a lifestyle likely similar to living albatrosses, the giant extinct pelagornithids, with their very long-pointed wings, would have flown widely over the ancient open seas, which had yet to be dominated by whales and seals, in search of squid, fish and other seafood to catch with their beaks lined with sharp pseudoteeth,” said Stidham. “The big ones are nearly twice the size of albatrosses, and these bony-toothed birds would have been formidable predators that evolved to be at the top of their ecosystem.”<br /><br />Museum collections like those in the UCMP, and the people like Kloess, Poust and Stidham to mine them, are key to reconstructing these ancient habitats.<br /><br />“Collections are vastly important, so making discoveries like this pelagornithid wouldn’t have happened if we didn’t have these specimens in the public trust, whether at UC Riverside or now at Berkeley,” Kloess said. “The fact that they exist for researchers to look at and study has incredible value.” </p><p style="text-align: left;"><br /></p><p style="text-align: left;"><u><i>The above story is based on <a href="https://news.berkeley.edu/2020/10/27/antarctica-yields-oldest-fossils-of-giant-birds-with-21-foot-wingspans/" rel="nofollow" target="_blank">materials </a>provided by  <a href="https://www.berkeley.edu/" rel="nofollow" target="_blank">University of California, Berkeley.</a></i></u><br /></p>

Antarctica Yields Oldest Fossils of Giant Birds With 21-foot Wingspans

A paleontologist cleans a fossilized bird cranium at Peru’s National History Museum in Lima, Friday, Photo: Martin Mejia, Associated Press F...

Fault Near Portland Could Unleash a Major Earthquake

Earthquakes, Tectonic 6:02 PM

<p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://1.bp.blogspot.com/-rXctWVILZNI/X5Lv45XJS7I/AAAAAAAASnA/Gh0rS8I2XIEtrlPujK76eg09NIv1jcQVACLcBGAsYHQ/s1276/Portland-Cascadia-Subduction-Zone%2B%25281%2529.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="635" data-original-width="1276" height="318" src="https://1.bp.blogspot.com/-rXctWVILZNI/X5Lv45XJS7I/AAAAAAAASnA/Gh0rS8I2XIEtrlPujK76eg09NIv1jcQVACLcBGAsYHQ/w640-h318/Portland-Cascadia-Subduction-Zone%2B%25281%2529.jpg" title="New evidence for geologically recent earthquakes near Portland, Oregon metro area" width="640" /></a></div> <br /><p></p><p> </p><p>New evidence for geologically recent earthquakes near Portland, Oregon metro area<br /></p><p>A fault near Portland, Oregon, has the capacity to cause strong shaking in the region — and has done so as recently as 1,000 years ago. <br /></p><p>A paleoseismic trench dug across the Gales Creek fault, located about 35 kilometers (roughly 22 miles) west of Portland, Oregon, documents evidence for three surface-rupturing earthquakes that took place about 8,800, 4,200 and 1,000 years ago.<br /><br />The findings, published in the Bulletin of the Seismological Society of America, suggest that earthquakes occur about every 4,000 years on the fault. If the full 73-kilometer (45 miles) fault were to rupture, the result could be a magnitude 7.1 to 7.4 earthquake that would pose significant seismic hazard to the Portland metro area, according to Alison Horst and her colleagues.<br /><br />By comparison, the 1993 Scotts Mills earthquake about 50 kilometers (31 miles) south of Portland was a magnitude 5.7 earthquake, and caused damages totaling about $30 million, the researchers noted.<br /><div style="width:100%;margin: 0px auto">
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</div><br />The region is part of the seismically active Cascadia subduction zone, where the Juan de Fuca tectonic plate bends beneath the North American plate. The Gales Creek fault lays within the Cascadia forearc, the land wedged between the oceanic trench where the Juan de Fuca begins its bend and the line of Cascadia volcanoes in Washington State and Oregon that are fueled by the subducting plate.<br /><br />"In general, little paleoseismic work has been done on forearc faults in Oregon, but many faults in the region are of interest based on their proximity to population centers," said Horst, a paleoseismologist formerly at Portland State University and now at the Washington State Department of Resources.<br /><br />Mapping and analyzing faults in the Pacific Northwest can be difficult, since fault surface traces are often covered by urban development and thick forests, or are difficult to reach in mountainous areas. To learn more about possible recent seismic activity along these forearc faults, Horst and her colleagues dug a trench across the Gales Creek fault, which had been mapped previously and is being investigated by the U.S. Bureau of Reclamation and the U.S. Geological Survey along part of the fault that projected through Scoggins Dam in Oregon's Washington County<br /><br />The Reclamation project had turned up evidence of surface deformation along the fault in sediments from the most recent geological time period, called the Holocene. After digging a trench across the fault -- first by hand and later by backhoe -- the researchers looked for evidence of past earthquakes in the rock layers, assigning an estimated date for each earthquake using radiocarbon analysis of charcoal contained in the layers.<br /><br />The trenching turned up strong evidence for at least three Holocene-age surface-rupturing earthquakes along the fault, with some weaker signs of one potential earthquake occurring after 1,000 years ago, and one earthquake occurring before 8,800 years ago.<br /><br />The researchers also estimated the magnitude of an earthquake that would rupture the entire mapped length of the Gales Creek fault, assuming that the full length ruptured at once and that the rupture event did not extend across multiple faults.<br /><br />"The linkage between rupture on the Gales Creek fault and neighboring faults is still unknown, as there are no other paleoseismic studies with earthquake ages for neighboring faults and as a result no indication of paleo-earthquakes with overlapping age estimates on neighboring faults," Horst explained. "Future work on faults in the region could allow us to improve our understanding of the connectivity of rupture on these low slip, long recurrence forearc faults."<br /><br />The findings suggest that other faults within the Oregon portion of the Cascadia forearc should be studied for signs of Holocene earthquakes, the researchers concluded.<br /></p><br /><span style="font-family: trebuchet;"><u><i>The above story is based on  <a href="https://www.seismosoc.org/news/new-evidence-for-geologically-recent-earthquakes-near-portland-oregon/" rel="nofollow" target="_blank">Materials</a> provided by <a href="http://www.seismosoc.org/" rel="nofollow" target="_blank">Seismological Society of America</a></i></u></span>

Fault Near Portland Could Unleash a Major Earthquake

New evidence for geologically recent earthquakes near Portland, Oregon metro area A fault near Portland, Oregon, has the capacity to cau...

Long-Lost Tectonic Plate Discovered Hundreds of Miles Below Canada

Earth History, Tectonic 6:11 PM

<p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-u3VXgRjWiHs/X5Gfs0ULJXI/AAAAAAAASm0/rXbxqY4sfc48jc9hGIPU2dr_ePz1g9llgCLcBGAsYHQ/s1196/Long-Lost%2BTectonic%2BPlate%2BDiscovered%2BHundreds%2Bof%2BMiles%2BBelow%2BCanada.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="756" data-original-width="1196" height="404" src="https://1.bp.blogspot.com/-u3VXgRjWiHs/X5Gfs0ULJXI/AAAAAAAASm0/rXbxqY4sfc48jc9hGIPU2dr_ePz1g9llgCLcBGAsYHQ/w640-h404/Long-Lost%2BTectonic%2BPlate%2BDiscovered%2BHundreds%2Bof%2BMiles%2BBelow%2BCanada.jpg" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">A 3D block diagram across North America showing a mantle tomography image reveals the Slab Unfolding method used to flatten the Farallon tectonic plate. By doing this, Fuston and Wu were able to locate the lost Resurrection plate.<br /></td></tr></tbody></table> <br /></p><p>Geologists agree that some 60 million years ago, the Farallon and Kula tectonic plates covered a vast area of Earth's surface across the Pacific Ocean, off the coast of North America. However, there's debate about whether a third plate existed, called Resurrection.<br /><br />The existence of a tectonic plate called Resurrection has long been a topic of debate among geologists, with some arguing it was never real. Others say it subducted -- moved sideways and downward -- into the earth's mantle somewhere in the Pacific Margin between 40 and 60 million years ago.<br /><br />A team of geologists at the University of Houston College of Natural Sciences and Mathematics believes they have found the lost plate in northern Canada by using existing mantle tomography images -- similar to a CT scan of the earth's interior. The findings, published in Geological Society of America Bulletin, could help geologists better predict volcanic hazards as well as mineral and hydrocarbon deposits.<br /><div style="width:100%;margin: 0px auto">
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</div><br />"Volcanoes form at plate boundaries, and the more plates you have, the more volcanoes you have," said Jonny Wu, assistant professor of geology in the Department of Earth and Atmospheric Sciences. "Volcanoes also affect climate change. So, when you are trying to model the earth and understand how climate has changed since time, you really want to know how many volcanoes there have been on earth."<br /><br />Wu and Spencer Fuston, a third-year geology doctoral student, applied a technique developed by the UH Center for Tectonics and Tomography called slab unfolding to reconstruct what tectonic plates in the Pacific Ocean looked like during the early Cenozoic Era. </p><p>The rigid outermost shell of Earth, or lithosphere, is broken into tectonic plates and geologists have always known there were two plates in the Pacific Ocean at that time called Kula and Farallon. But there has been discussion about a potential third plate, Resurrection, having formed a special type of volcanic belt along Alaska and Washington State.<br /><br />"We believe we have direct evidence that the Resurrection plate existed. We are also trying to solve a debate and advocate for which side our data supports," Fuston said.<br /><br />Using 3D mapping technology, Fuston applied the slab unfolding technique to the mantle tomography images to pull out the subducted plates before unfolding and stretching them to their original shapes.<br /><br />"When 'raised' back to the earth's surface and reconstructed, the boundaries of this ancient Resurrection tectonic plate match well with the ancient volcanic belts in Washington State and Alaska, providing a much sought after link between the ancient Pacific Ocean and the North American geologic record," explained Wu.</p><p> </p><span style="font-family: trebuchet;"><u><i>The above story is based on <a href="https://uh.edu/news-events/stories/2020/october-2020/10202020-uh-geologists-find-lost-tectonic-plate.php" rel="nofollow" target="_blank">Materials</a> provided by <a href="http://www.uh.edu/" rel="nofollow" target="_blank">University of Houston</a>.</i></u></span>

Long-Lost Tectonic Plate Discovered Hundreds of Miles Below Canada

A 3D block diagram across North America showing a mantle tomography image reveals the Slab Unfolding method used to flatten the Farallon tec...

Geologists Solve Crucial Mystery Surrounding The Deposits of Rare Earth Elements

Geochemistry, Mining, Researches 6:09 PM

<p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-RQxTEic8yVY/X5BO1-O_4yI/AAAAAAAASmk/LnBlaNeYghMWX4FibHBcTKX3Xfj0QjRCwCLcBGAsYHQ/s1555/Geologists%2BSolve%2BCrucial%2BMystery%2BSurrounding%2BThe%2BDeposits%2Bof%2BRare%2BEarth%2BElements%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1031" data-original-width="1555" height="424" src="https://1.bp.blogspot.com/-RQxTEic8yVY/X5BO1-O_4yI/AAAAAAAASmk/LnBlaNeYghMWX4FibHBcTKX3Xfj0QjRCwCLcBGAsYHQ/w640-h424/Geologists%2BSolve%2BCrucial%2BMystery%2BSurrounding%2BThe%2BDeposits%2Bof%2BRare%2BEarth%2BElements%2B%25281%2529.jpg" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">A handful of europium. Credit: Alchemist-hp, CC BY-SA<br /></td></tr></tbody></table> <br /></p><p>An international team of scientists has helped to unravel a longstanding mystery about how rare earth element deposits form underground – and sometimes seem to disappear without a trace.<br /><br /></p><p>Pioneering new research has helped geologists solve a long-standing puzzle that could help pinpoint new, untapped concentrations of some the most valuable rare earth deposits.<br /><br />A team of geologists, led by Professor Frances Wall from the Camborne School of Mines, have discovered a new hypothesis to predict where rare earth elements neodymium and dysprosium could be found.<br /><br />The elements are among the most sought after, because they are an essential part of digital and clean energy manufacturing, including magnets in large wind turbines and electric cars motors.<br /><br />For the new research, scientists conducted a series of experiments that showed sodium and potassium -- rather than chlorine or fluorine as previously thought -- were the key ingredients for making these rare earth elements soluble.<br /><br />This is crucial as it determines whether they crystalise -- making them fit for extraction -- or stayed dissolved in fluids.<br /><div style="width:100%;margin: 0px auto">
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</div><br />The experiments could therefore allow geologists to make better predictions about where the best concentrations of neodymium and dysprosium are likely to be found.<br /><br />The results are published in the journal, Science Advances on Friday, October 9th 2020.<br /><br />University of Exeter researchers, through the 'SoS RARE' project, have previously studied many natural examples of the roots of very unusual extinct carbonatite volcanoes, where the world's best rare earth deposits occur, in order to try and identify potential deposits of the rare earth minerals.<br /><br />However, in order to gain a greater insight into their results, they invited Michael Anenburg to join the team to carry out experiments at the Australian National University (ANU).<br /><br />He simulated the crystallisation of molten carbonate magma to find out which elements would be concentrated in the hot waters left over from the crystallisation process.<br /><br />It showed that sodium and potassium make the rare earths soluble in solution. Without sodium and potassium, rare earth minerals precipitate in the carbonatite itself. With sodium, intermediate minerals like burbankite form and are then replaced. With potassium, dysprosium is more soluble than neodymium and carried out to the surrounding rocks.<br /><br />Professor Frances Wall, leader of the SoS RARE project said: "This is an elegant solution that helps us understand better where 'heavy' rare earths like dysprosium and 'light' rare earths like neodymium' may be concentrated in and around carbonatite intrusions. We were always looking for evidence of chloride-bearing solutions but failing to find it. These results give us new ideas."<br /><br />Michael Anenburg , a Postdoctoral Fellow at ANU said: "My tiny experimental capsules revealed minerals that nature typically hides from us. It was a surprise how well they explain what we see in natural rocks and ore deposits." </p><br /><span style="font-family: trebuchet;"><u><i>The above story is based on <a href="https://www.exeter.ac.uk/news/homepage/title_821137_en.html" rel="nofollow" target="_blank">Materials</a> provided by <a href="http://www.exeter.ac.uk/" rel="nofollow" target="_blank">University of Exeter</a>.</i></u></span>

Geologists Solve Crucial Mystery Surrounding The Deposits of Rare Earth Elements

A handful of europium. Credit: Alchemist-hp, CC BY-SA An international team of scientists has helped to unravel a longstanding mystery abo...

Seismic Study Proves Rain Really Can Move Mountains

Geology, sedimentary 6:17 PM

<p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><img alt="Seismic Study Proves Rain Really Can Move Mountains" border="0" data-original-height="672" data-original-width="1008" height="426" src="https://1.bp.blogspot.com/-wFFynIzTBM8/X4xbZqkc4mI/AAAAAAAASmI/spbzDJafbJAzGQ02uhPXarmQqJCMl4MKQCLcBGAsYHQ/w640-h426/Seismic%2BStudy%2BProves%2BRain%2BReally%2BCan%2BMove%2BMountains.jpg" style="margin-left: auto; margin-right: auto;" width="640" /></td></tr><tr><td class="tr-caption" style="text-align: center;">Painted Desert Arizona<br /></td></tr></tbody></table><p> <br /></p><p>A pioneering technique which captures precisely how mountains bend to the will of raindrops has helped to solve a long-standing scientific enigma.<br /><br />The dramatic effect rainfall has on the evolution of mountainous landscapes is widely debated among geologists, but new research led by the University of Bristol and published today in Science Advances, clearly calculates its impact, furthering our understanding of how peaks and valleys have developed over millions of years.<br /><br />Its findings, which focused on the mightiest of mountain ranges -- the Himalaya -- also pave the way for forecasting the possible impact of climate change on landscapes and, in turn, human life.<br /><br />Lead author Dr Byron Adams, Royal Society Dorothy Hodgkin Fellow at the university's Cabot Institute for the Environment, said: "It may seem intuitive that more rain can shape mountains by making rivers cut down into rocks faster. But scientists have also believed rain can erode a landscape quickly enough to essentially 'suck' the rocks out of the Earth, effectively pulling mountains up very quickly.<br /><br />"Both these theories have been debated for decades because the measurements required to prove them are so painstakingly complicated. That's what makes this discovery such an exciting breakthrough, as it strongly supports the notion that atmospheric and solid earth processes are intimately connected."<br /><br />While there is no shortage of scientific models aiming to explain how the Earth works, the greater challenge can be making enough good observations to test which are most accurate.<br /></p><div style="margin: 0px auto; width: 100%;">
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</div><br />The study was based in the central and eastern Himalaya of Bhutan and Nepal, because this region of the world has become one of the most sampled landscapes for erosion rate studies. Dr Adams, together with collaborators from Arizona State University (ASU) and Louisiana State University, used cosmic clocks within sand grains to measure the speed at which rivers erode the rocks beneath them.<br /><br />"When a cosmic particle from outer space reaches Earth, it is likely to hit sand grains on hillslopes as they are transported toward rivers. When this happens, some atoms within each grain of sand can transform into a rare element. By counting how many atoms of this element are present in a bag of sand, we can calculate how long the sand has been there, and therefore how quickly the landscape has been eroding," Dr Adams said.<br /><br />"Once we have erosion rates from all over the mountain range, we can compare them with variations in river steepness and rainfall. However, such a comparison is hugely problematic because each data point is very difficult to produce and the statistical interpretation of all the data together is complicated."<br /><br />Dr Adams overcame this challenge by combining regression techniques with numerical models of how rivers erode.<br /><br />"We tested a wide variety of numerical models to reproduce the observed erosion rate pattern across Bhutan and Nepal. Ultimately only one model was able to accurately predict the measured erosion rates," Dr Adams said.<br /><br />"This model allows us for the first time to quantify how rainfall affects erosion rates in rugged terrain."<br /><br />Research collaborator Professor Kelin Whipple, Professor of Geology at ASU, said: "Our findings show how critical it is to account for rainfall when assessing patterns of tectonic activity using topography, and also provide an essential step forward in addressing how much the slip rate on tectonic faults may be controlled by climate-driven erosion at the surface."<br /><br />The study findings also carry important implications for land use management, infrastructure maintenance, and hazards in the Himalaya.<br /><br />In the Himalaya, there is the ever-present risk that high erosion rates can drastically increase sedimentation behind dams, jeopardising critical hydropower projects. The findings also suggest greater rainfall can undermine hillslopes, increasing the risk of debris flows or landslides, some of which may be large enough to dam the river creating a new hazard -- lake outburst floods.<br /><br />Dr Adams added: "Our data and analysis provides an effective tool for estimating patterns of erosion in mountainous landscapes such as the Himalaya, and thus, can provide invaluable insight into the hazards that influence the hundreds of millions of people who live within and at the foot of these mountains."<br /><br />The research was funded by the Royal Society, the UK Natural Environmental Research Council (NERC), and the National Science Foundation (NSF) of the US.<br /><br />Building on this important research, Dr Adams is currently exploring how landscapes respond after large volcanic eruptions.<br /><br />"This new frontier of landscape evolution modelling is also shedding new light on volcanic processes. With our cutting-edge techniques to measure erosion rates and rock properties, we will be able to better understand how rivers and volcanoes have influenced each other in the past," Dr Adams said.<br /><br />"This will help us to more accurately anticipate what is likely to happen after future volcanic eruptions and how to manage the consequences for communities living nearby."<p></p><br /><u><i><span style="font-family: trebuchet;"> The above story is based on <a href="https://www.bristol.ac.uk/news/2020/october/rain-moves-mountains.html" rel="nofollow" target="_blank">Materials</a> provided by <a href="https://www.bristol.ac.uk/" rel="nofollow" target="_blank">University of Bristol</a>. </span></i></u>

Seismic Study Proves Rain Really Can Move Mountains

Painted Desert Arizona A pioneering technique which captures precisely how mountains bend to the will of raindrops has helped to solve a l...

Turning Diamond Into Metal

Diamonds, Geochemistry, Researches 6:11 PM

<p></p><div class="separator" style="clear: both; text-align: center;"><img border="0" data-original-height="915" data-original-width="1624" height="360" src="https://1.bp.blogspot.com/-s5ChNSkHbSs/X4m3z5GVbRI/AAAAAAAASl8/Mk_yawsxhcMvgxIk-nisvtPsnStGlO56gCLcBGAsYHQ/w640-h360/Turning%2BDiamond%2BInto%2BMetal%2B%25281%2529.jpg" width="640" /></div> <br /><p></p><p> </p><p>Long known as the hardest of all natural materials, diamonds are also exceptional thermal conductors and electrical insulators. Now, researchers have discovered a way to tweak tiny needles of diamond in a controlled way to transform their electronic properties, dialing them from insulating, through semiconducting, all the way to highly conductive, or metallic. This can be induced dynamically and reversed at will, with no degradation of the diamond material.<br /><br />The research, though still at an early proof-of-concept stage, may open up a wide array of potential applications, including new kinds of broadband solar cells, highly efficient LEDs and power electronics, and new optical devices or quantum sensors, the researchers say.<br /><br />Their findings, which are based on simulations, calculations, and previous experimental results, are reported this week in the Proceedings of the National Academy of Sciences. The paper is by MIT Professor Ju Li and graduate student Zhe Shi; Principal Research Scientist Ming Dao; Professor Subra Suresh, who is president of Nanyang Technological University in Singapore as well as former dean of engineering and Vannevar Bush Professor Emeritus at MIT; and Evgenii Tsymbalov and Alexander Shapeev at the Skolkovo Institute of Science and Technology in Moscow.<br /><br />The team used a combination of quantum mechanical calculations, analyses of mechanical deformation, and machine learning to demonstrate that the phenomenon, long theorized as a possibility, really can occur in nanosized diamond.<br /><div style="width:100%;margin: 0px auto">
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</div><br />The concept of straining a semiconductor material such as silicon to improve its performance found applications in the microelectronics industry more than two decades ago. However, that approach entailed small strains on the order of about 1 percent. Li and his collaborators have spent years developing the concept of elastic strain engineering. This is based on the ability to cause significant changes in the electrical, optical, thermal, and other properties of materials simply by deforming them -- putting them under moderate to large mechanical strain, enough to alter the geometric arrangement of atoms in the material's crystal lattice, but without disrupting that lattice.<br /><br />In a major advance in 2018, a team led by Suresh, Dao, and Lu Yang from the Polytechnic University of Hong Kong showed that tiny needles of diamond, just a few hundred nanometers across, could be bent without fracture at room temperature to large strains. They were able to repeatedly bend these nanoneedles to tensile strain as much as 10 percent; the needles can then return intact to their original shape.<br /><br />Key to this work is a property known as bandgap, which essentially determines how readily electrons can move through a material. This property is thus key to the material's electrical conductivity. Diamond normally has a very wide bandgap of 5.6 electron volts, meaning that it is a strong electrical insulator that electrons do not move through readily. In their latest simulations, the researchers show that diamond's bandgap can be gradually, continuously, and reversibly changed, providing a wide range of electrical properties, from insulator through semiconductor to metal.<br /><br />"We found that it's possible to reduce the bandgap from 5.6 electron volts all the way to zero," Li says. "The point of this is that if you can change continuously from 5.6 to 0 electron volts, then you cover all the range of bandgaps. Through strain engineering, you can make diamond have the bandgap of silicon, which is most widely used as a semiconductor, or gallium nitride, which is used for LEDs. You can even have it become an infrared detector or detect a whole range of light all the way from the infrared to the ultraviolet part of the spectrum."<br /><br />"The ability to engineer and design electrical conductivity in diamond without changing its chemical composition and stability offers unprecedented flexibility to custom-design its functions," says Suresh. "The methods demonstrated in this work could be applied to a broad range of other semiconductor materials of technological interest in mechanical, microelectronics, biomedical, energy and photonics applications, through strain engineering."<br /><br />So, for example, a single tiny piece of diamond, bent so that it has a gradient of strain across it, could become a solar cell capable of capturing all frequencies of light on a single device -- something that currently can only be achieved through tandem devices that couple different kinds of solar cell materials together in layers to combine their different absorption bands. These might someday be used as broad-spectrum photodetectors for industrial or scientific applications.<br /><br />One constraint, which required not only the right amount of strain but also the right orientation of the diamond's crystalline lattice, was to prevent the strain from causing the atomic configuration to cross a tipping point and turning into graphite, the soft material used in pencils.<br /><br />The process can also make diamond into two types of semiconductors, either "direct" or "indirect" bandgap semiconductors, depending on the intended application. For solar cells, for example, direct bandgaps provide a much more efficient collection of energy from light, allowing them to be much thinner than materials such as silicon, whose indirect bandgap requires a much longer pathway to collect a photon's energy.<br /><br />The process could be relevant for a wide variety of potential applications, Li suggests, such as for highly sensitive quantum-based detectors that use defects and dopant atoms in a diamond. "Using strain, we can control the emission and absorption levels of these point defects," he says, allowing novel ways of controlling their electronic and nuclear quantum states.<br /><br />But given the great variety of conditions made possible by the different dimensions of strain variations, Li says, "if we have a particular application in mind, then we could optimize toward that application target. And what is nice about the elastic straining approach is that it is dynamic," so that it can be continuously varied in real time as needed.<br /><br />This early-stage proof-of-concept work is not yet at the point where they can begin to design practical devices, the researchers say, but with the ongoing research they expect that practical applications could be possible, partly because of promising work being done around the world on the growth of homogeneous diamond materials.</p><br /><i><u> The above story is based on <a href="https://news.mit.edu/2020/diamond-metal-conductor-1005" rel="nofollow" target="_blank">Materials</a> provided by <a href="http://web.mit.edu/" rel="nofollow" target="_blank">Massachusetts Institute of Technology</a>. Original written by David L. Chandler</u></i>

Turning Diamond Into Metal

Long known as the hardest of all natural materials, diamonds are also exceptional thermal conductors and electrical insulators. Now, res...

800 Years Ago, Old Faithful Went Quiet. Soon, It Might Happen Again

Tectonic, Yellowstone 6:52 PM

<p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><img alt="Old Faithful Geyser next to the Old Faithful Inn, illustrating how high the eruptions can reach. Photo: Jeff Vanuga" border="0" data-original-height="692" data-original-width="1200" height="370" src="https://1.bp.blogspot.com/-MsVkFw0PDQM/X4cedXLArvI/AAAAAAAASlw/uBSgSQV2wiouTb4Rg3_xUPEEJPKDv4FrQCLcBGAsYHQ/w640-h370/800%2BYears%2BAgo%252C%2BOld%2BFaithful%2BWent%2BQuiet%2B%25281%2529.jpg" style="margin-left: auto; margin-right: auto;" width="640" /></td></tr><tr><td class="tr-caption" style="text-align: center;">Old Faithful Geyser next to the Old Faithful Inn, illustrating how high the eruptions can reach.<br />Photo: Jeff Vanuga<br /></td></tr></tbody></table></p><div class="separator" style="clear: both; text-align: center;"></div> <br /><p></p><p>Old Faithful, the famed geyser in Yellowstone National Park, erupts with such captivating regularity, they named the whole gushing spring after it.<br /><br />Phenomenal bursts of hot water and steam – fed by the geothermal activity of the Yellowstone supervolcano underneath – spurt up with such punctuality they can even be predicted, giving the geyser the nickname of Eternity's Timepiece. But Old Faithful wasn't always so faithful, and in times long ago, Eternity's Timepiece stopped ticking entirely.<br /><br />In the last several decades, scientists have observed that Old Faithful's interval between eruptions (IBEs) has changed considerably, stretching from about 60–65 minutes in the 1950s to about 90–94 minutes since 2001.<br /><br />To investigate why – and probe the links between Old Faithful's IBE variations and long-term drought variability in the region – in a new study, researchers from the US Geological Survey (USGS) collected several remnants of mineralised wood found around the mound upon which Old Faithful sits.<br /><br />Today, the mound is barren and empty of trees - they do not grow on active geyser mounds, as the constant deluge and splatter of the scalding, alkaline-rich discharge would be incompatible with germination and seedling growth.<br /><div style="width:100%;margin: 0px auto">
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</div><br />Nonetheless, a pioneering study decades ago did analyse an ancient wood sample recovered from Old Faithful, suggesting that, once upon a time at least, the geyser's eruptions did relent for a while and trees grew in its location.<br /><br />Inspired to learn more, the USGS team analysed 13 mineralised wood samples they recovered from Old Faithful's mound, with radiocarbon dating suggesting these trees grew in Yellowstone several centuries ago, around 1233 to 1362 CE.<br /><br />"When I submitted the samples for radiocarbon dating I didn't know whether they would be hundreds or thousands of years old," first author and USGS geologist Shaul Hurwitz told Science.<br /><br />"It was an 'aha!' moment when they all clustered within a hundred-year period in the 13th and 14th centuries."<br /><br />To figure out why and how these trees were all able to live in this relatively brief, decades-long time window during which Old Faithful seemingly stopped erupting, the researchers looked for historical data that could explain drought conditions at the time, where reduced precipitation and lower groundwater supply would turn off the taps for the iconic geyser.<br /><br />They didn't have to look far, with previous local tree ring data indicating pronounced megadroughts across the region and in other parts of the world too, resulting from severe conditions during an episode known as the Medieval Climate Anomaly (aka Medieval Warm Period).<br /><br />"It's the time when we have things like grapes growing in Northern England and a loss of sea ice that allowed people to discover Greenland," palaeoclimatologist Cathy Whitlock from Montana State University, who wasn't involved in the study, explained to Inside Science.<br /><br />"We know in Yellowstone it was both warmer and drier. The upper tree line was higher up the slopes and there is evidence of more fires during that period."<br /><br />The links the team found don't just fill in the gaps on Old Faithful's historical time-keeping. They may also point to geyser eruption variations in the future, as the world gets increasingly hotter and drier in the face of climate change.<br /><br />That's something Hurwitz foreshadowed over a decade ago, and even though Eternity's Timepiece has shown it can be a bit unreliable sometimes, the real clock never stops.<br /><br />"Climate models project increasingly severe droughts and large fires by mid-century leading to a major transformation of Yellowstone's ecosystems," the team writes.<br /><br />"Periods of decreased precipitation have been shown in modern observational records to result in less frequent eruptions of Old Faithful Geyser, while the new 14C dates of mineralised wood suggest that severe, long-duration drought events can lead to Old Faithful Geyser eruption cessation."</p><p> </p><p><u><i> The above story is based on <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020GL089871" rel="nofollow" target="_blank">materials </a>provided by  Montana State University.</i></u><br /></p>

800 Years Ago, Old Faithful Went Quiet. Soon, It Might Happen Again

Old Faithful Geyser next to the Old Faithful Inn, illustrating how high the eruptions can reach. Photo: Jeff Vanuga Old Faithful, the fame...

What Lies Beneath a Volcano?

Geology, Tectonic, volcano 5:50 PM

<p></p><div class="separator" style="clear: both; text-align: center;"><img border="0" data-original-height="1491" data-original-width="1194" height="640" src="https://1.bp.blogspot.com/-seKYoSriaEU/X4W-YsZGtoI/AAAAAAAASlk/at-umvPQuSo2UVkEIJM9W59P_aeTdcr4wCLcBGAsYHQ/w512-h640/What%2BLies%2BBeneath%2Ba%2BVolcano.jpg" width="512" /></div> <p></p><p>The complex plumbing system beneath volcanoes has been revealed in the clearest detail ever, marking a "major step forward" in our understanding of how they are formed and behave.<br /><br />An international team of geologists has analyzed the subsurface geology of the Erlend volcano in the Faroe-Shetland basin of the North Atlantic, allowing them to produce a detailed 3-D map showing the volcano's inner workings. It was once a small volcanic island that last erupted 58 million years ago, and is now buried and preserved underneath 1 km of sediment on the sea floor.<br /><br />Instead of observing one large magma chamber beneath the volcano, the map reveals a complex amalgamation of smaller volcanic rock formations. It also suggests the long-assumed concept of a vertical, cylinder-like conduit that connects magma chambers and volcanoes—the 'balloon and straw' – is oversimplified.<br /><br />The map is revealed as part of a paper published in the journal Geology, co-authored by geologists at the universities of Aberdeen, Adelaide, and Oslo. It is part of a project led by Faye Walker, a Ph.D. student at Aberdeen and participant in the Natural Environment Research Council's (NERC) Center for Doctoral Training in Oil and Gas.<br /><div style="width:100%;margin: 0px auto">
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</div><br />The team looked at seismic data provided by energy data company TGS, to understand the interaction of volcanic rock with petroleum systems in the far north of the Faroe-Shetland Basin, an area with significant gas reserves.<br /><br />Aberdeen Ph.D. student Faye Walker, who carried out the analysis of the 3-D seismic data, said:<br /><br />"Much of our understanding of how magma is moved around the Earth's crust is still conceptual, but by producing the clearest images yet of the complex plumbing systems that underlie volcanoes, we can see things with our own eyes. This is a major step forward in terms of advancing the science around how volcanoes are formed and behave."<br /><br />Dr. Nick Schofield, from the University of Aberdeen's School of Geosicences, added:<br /><br />"Understanding the plumbing systems below volcanoes is usually really challenging, but this work has revealed this in detail. Understanding the plumbing systems below volcanoes is usually really challenging, and to see them in the field the overlying volcano has to be eroded. This makes understanding the connection between the magma and understanding how it transits into the volcano difficult. This work has revealed this in detail. In terms of oil and gas exploration, the area in which the data was collected is potentially really important for the UK's future gas needs as part of the energy transition, where gas has a vital role as a 'carbon bridge' leading to a greener future. Understanding the size of the magma chamber and the heating effect on the rocks which produce oil and gas will lead to better understanding of the area's potential."<br /><br />Dr. Simon Holford, from the University of Adelaide, said the findings could potentially play an important role in helping to predict future eruptions in active volcanoes.<br /><br />"Understanding how molten rock makes its way from the chamber, though the Earth's crust, to the volcanoes where it is erupted is one of the biggest challenges facing geologists," he explained.<br /><br />"Understanding how magma is stored prior to eruptions is essential in assessing volcanic hazards, but it is extremely difficult to directly observe magma chambers. Active volcanoes are challenging places to work and collect data, whilst ancient volcanoes and their underlying plumbing systems are rarely completed preserved. That is what makes our findings so valuable. These images reframe our understanding and suggest that models for predicting volcanic eruptions will need to be modified." </p><p><br /></p><p><u><i>The above story is based on <a href="http://dx.doi.org/10.1130/G47941.1" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.abdn.ac.uk/" rel="nofollow" target="_blank">University of Aberdeen.</a></i></u><br /></p>

What Lies Beneath a Volcano?

The complex plumbing system beneath volcanoes has been revealed in the clearest detail ever, marking a "major step forward" in o...

Earth Grows Fine Gemstones in Minutes

gemstones, Geochemistry, Geology 6:18 PM

<p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><img alt="Earth Grows Fine Gemstones in Minutes" border="0" data-original-height="1269" data-original-width="1452" height="560" src="https://1.bp.blogspot.com/-l7Id5hOCfzY/X4RzKNYB43I/AAAAAAAASkw/52qF3ajR7s0ZLYZuy4G0hcvJjNDIgW4lwCLcBGAsYHQ/w640-h560/Earth%2BGrows%2BFine%2BGemstones%2Bin%2BMinutes.jpg" style="margin-left: auto; margin-right: auto;" width="640" /></td></tr><tr><td class="tr-caption" style="text-align: center;">Tanzanite crystal. photo: Collector's Edge Minerals<br /></td></tr></tbody></table><p></p><div class="separator" style="clear: both; text-align: center;"></div> <p>Rome wasn't built in a day, but some of Earth's finest gemstones were, according to new research from Rice University.<br /><br />Aquamarine, emerald, garnet, zircon and topaz are but a few of the crystalline minerals found mostly in pegmatites, veinlike formations that commonly contain both large crystals and hard-to-find elements like tantalum and niobium. Another common find is lithium, a vital component of electric car batteries.<br /><br />"This is one step towards understanding how Earth concentrates lithium in certain places and minerals," said Rice graduate student Patrick Phelps, co-author of a study published online in Nature Communications. "If we can understand the basics of pegmatite growth rates, it's one step in the direction of understanding the whole picture of how and where they form."<br /><br />Pegmatites are formed when rising magma cools inside Earth, and they feature some of Earth's largest crystals. South Dakota's Etta mine, for example, features log-sized crystals of lithium-rich spodumene, including one 42 feet in length in weighing an estimated 37 tons. The research by Phelps, Rice's Cin-Ty Lee and Southern California geologist Douglas Morton attempts to answer a question that has long vexed mineralogists: How can such large crystals be in pegmatites?<br /><br />"In magmatic minerals, crystal size is traditionally linked to cooling time," said Lee, Rice's Harry Carothers Wiess Professor of Geology and chair of the Department of Earth, Environmental and Planetary Sciences at Rice. "The idea is that large crystals take time to grow."<br /></p><div style="margin: 0px auto; width: 100%;">
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</div><br />Magma that cools rapidly, like rock in erupted lavas, contains microscopic crystals, for example. But the same magma, if cooled over tens of thousands of years, might feature centimeter-sized crystals, Lee said.<br /><br />"Pegmatites cool relatively quickly, sometimes in just a few years, and yet they feature some of the largest crystals on Earth," he said. "The big question is really, 'How can that be?'"<br /><br />When Phelps began the research, his most immediate questions were about how to formulate a set of measurements that would allow him, Lee and Morton to answer the big question.<br /><br />"It was more a question of, 'Can we figure out how fast they actually grow?'" Phelps said. "Can we use trace elements -- elements that don't belong in quartz crystals -- to figure out the growth rate?"<br /><br />It took more than three years, a field trip to gather sample crystals from a pegmatite mine in Southern California, hundreds of lab measurements to precisely map the chemical composition of the samples and a deep dive into some 50-year-old materials science papers to create a mathematical model that could transform the chemical profiles into crystal growth rates.<br /><br />"We examined crystals that were half an inch wide and over an inch long," Phelps said. "We showed those grew in a matter of hours, and there is nothing to suggest the physics would be different in larger crystals that measure a meter or more in length. Based on what we found, larger crystals like that could grow in a matter of days."<br /><br />Pegmatites form where pieces of Earth's crust are drawn down and recycled in the planet's molten mantle. Any water that's trapped in the crust becomes part of the melt, and as the melt rises and cools, it gives rise to many kinds of minerals. Each forms and precipitates out of the melt at a characteristic temperature and pressure. But the water remains, making up a progressively higher percentage of the cooling melt.<br /><br />"Eventually, you get so much water left over that it becomes more of a water-dominated fluid than a melt-dominated fluid," Phelps said. "The leftover elements in this watery mixture can now move around a lot faster. Chemical diffusion rates are much faster in fluids and the fluids tend to flow more quickly. So when a crystal starts forming, elements can get to it faster, which means it can grow faster."<br /><br />Crystals are ordered arrangement of atoms. They form when atoms naturally fall into that arranged pattern based on their chemical properties and energy levels. For example, in the mine where Phelps collected his quartz samples, many crystals had formed in what appeared to be cracks that had opened while the pegmatite was still forming.<br /><br />"You see these pop up and go through the layers of pegmatite itself, almost like veins within veins," Phelps said. "When those cracks opened, that lowered the pressure quickly. So the fluid rushed in, because everything's expanding, and the pressure dropped dramatically. All of a sudden, all the elements in the melt are now confused. They don't want to be in that physical state anymore, and they rapidly start coming together in crystals."<br /><br />To decipher how quickly the sample crystals grew, Phelps used both cathodoluminescence microscopy and laser ablation with mass spectrometry to measure the precise amount of trace elements that had been incorporated into the crystal matrix at dozens of points during growth. From experimental work done by materials scientists in the mid-20th century, Phelps was able to decipher the growth rates from these profiles.<br /><br />"There are three variables," he said. "There's the likelihood of things getting brought in. That's the partition coefficient. There's how fast the crystal is growing, the growth rate. And then there's the diffusivity, so how quickly elemental nutrients are brought to the crystal."<br /><br />Phelps said the fast growth rates were quite a surprise.<br /><br />"Pegmatites are pretty short-lived, so we knew they had to grow relatively fast," he said. "But we were showing it was a few orders of magnitude faster than anyone had predicted.<br /><br />"When I finally got one of these numbers, I remember going into Cin-Ty's office, and saying, 'Is this feasible? I don't think this is right.'" Phelps recalled. "Because in my head, I was still kind of thinking about a thousand-year time scale. And these numbers were meaning days or hours.<br /><br />"And Cin-Ty said, 'Well, why not? Why can't it be right?'" Phelps said. "Because we'd done the math and the physics. That part was sound. While we didn't expect it to be that fast, we couldn't come up with a reason why it wasn't plausible."<p></p><p> </p><p><i><u> The above story is based on <a href="http://news.rice.edu/2020/10/06/earth-grows-fine-gems-in-minutes-2/" rel="nofollow" target="_blank">Materials</a> provided by <a href="http://www.rice.edu/" rel="nofollow" target="_blank">Rice University</a>. </u></i><span face=""Helvetica Neue", Helvetica, Arial, sans-serif" style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline; float: none; font-size: 14px; font-style: normal; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;"><span><br /></span></span></p>

Earth Grows Fine Gemstones in Minutes

Tanzanite crystal. photo: Collector's Edge Minerals Rome wasn't built in a day, but some of Earth's finest gemstones were, acc...

New Insights Into the Origin of Diamonds in Meteorites

Diamonds, Meteorite 6:33 PM

<p></p><div class="separator" style="clear: both; text-align: center;"><img alt="New Insights Into the Origin of Diamonds in Meteorites" border="0" data-original-height="845" data-original-width="1024" height="528" src="https://1.bp.blogspot.com/-_hMZPFkLhOc/X4MkaBwNL2I/AAAAAAAASkk/kVZ34xmD3BsLLoSQcSdjQlodFhL22G8FQCLcBGAsYHQ/w640-h528/New%2BInsights%2BInto%2Bthe%2BOrigin%2Bof%2BDiamonds%2Bin%2BMeteorites%2B%25281%2529.jpg" title="New Insights Into the Origin of Diamonds in Meteorites" width="640" /></div> <br /><p></p><p> </p><p>Scientists have offered new insights into the origin of diamonds in ureilites (a group of stony meteorites). These diamonds most likely formed by rapid shock transformation from graphite (the common low-pressure form of pure carbon) during one or more major impacts into the ureilite parent asteroid in the early solar system.<br /><br />Previously, researchers have proposed that diamonds in ureilites formed like those on Earth—deep in the mantle of the planet, where the high pressures needed to form diamond (a very dense, hard form of pure carbon), are created by the weight of overlying rock. If diamonds in ureilites formed this way, then the original parent body on which they formed must have been a large protoplanet – at least the size of Mars or Mercury.<br /><br />However, new research conducted by Prof. Fabrizio Nestola (University of Padova, Italy), Dr. Cyrena Goodrich (Universities Space Research Association at the Lunar and Planetary Institute) and their colleagues show there is no evidence requiring formation under the high static pressures and long growth time conditions of a planet's deep interior.<br /><div style="width:100%;margin: 0px auto">
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</div><br />The team investigated diamonds in three ureilite samples using electron microscopy, micro X-ray diffraction, and Raman (laser) spectroscopy. Their investigations revealed both large (up to 100 micrometers in size) and small (nanometers in size) grains of diamond, along with metallic iron and graphite, in the carbon-rich regions located among the silicate mineral grains in these samples.<br /><br />"We discovered the largest single-crystal diamond ever observed in a ureilite," says Dr. Cyrena Goodrich. "Importantly, the ureilites that we investigated have all been highly shocked, based on the evidence from their silicate minerals, which strongly suggests that both large and small diamonds in these rocks formed from original graphite via shock processes."<br /><br />The origin of diamonds in ureilites has important implications for models of planetary formation in the early solar system. Present day asteroids, from which most meteorites originate, are very small compared to the planets. However, planetary formation models predict that planets formed as a result of the accumulation of Moon- to Mars-sized planetary embryos (protoplanets). </p><p>Advocates of the high static pressure hypothesis for the origin of ureilite diamonds argue that the ureilite parent body was one of these embryos. However, Nestola and co-authors demonstrate that the presence of diamonds in ureilites does not require a Mars-sized parent body.<br /><br />Previously it was thought that micrometer-sized diamonds were too large to have formed in the short time periods (e.g., microseconds) during which peak pressures are maintained in impact events. However, Nestola et al. calculated that peak shock pressures could last for 4-5 seconds during a major impact such as that inferred for the ureilite parent body. </p><p>This is sufficient for formation of 100 micrometer-sized diamonds when catalyzed by the presence of metal, a process commonly used in production of diamonds in industry. Since metal is ubiquitously associated with the carbon phases in ureilites, catalyzed formation of large diamonds from original graphite under shock compression is very likely.<br /><br />Dr. Goodrich further notes, "Our findings are important because they not only indicate a shock origin for the diamonds in ureilites, as discussed by many previous researchers, they also refute arguments that have been made for the large parent body hypothesis. This type of scientific debate and testing of hypotheses is an essential part of making progress in science."</p><p> </p><p><u><i>The above story is based on <a href="http://dx.doi.org/10.1073/pnas.1919067117" rel="nofollow" target="_blank">materials </a>provided by  <a href="https://www.usra.edu/" rel="nofollow" target="_blank">Universities Space Research Association. </a></i></u><br /></p>

New Insights Into the Origin of Diamonds in Meteorites

Scientists have offered new insights into the origin of diamonds in ureilites (a group of stony meteorites). These diamonds most likely ...

Arkansas Man Finds 9-carat Diamond at Crater of Diamonds State Park

Mining, USA 7:10 PM

<p></p><div class="separator" style="clear: both; text-align: center;"><img alt="Arkansas Man Finds 9-carat Diamond at Crater of Diamonds State Park" border="0" data-original-height="787" data-original-width="1301" height="388" src="https://1.bp.blogspot.com/-q0WU-pwtxts/X33m3lMOmVI/AAAAAAAASj8/II30JdF9fk0vr_PamZYsGX2Cr9hanfgCwCLcBGAsYHQ/w640-h388/Arkansas%2BMan%2BFinds%2B9-carat%2BDiamond%2Bat%2BCrater%2Bof%2BDiamonds%2BState%2BPark.jpg" width="640" /></div> <br /><br /><p></p><p>Kevin Kinard was visiting Arkansas' Crater of Diamonds State Park when he discovered a 9.07 carat diamond.<br /><br />A bank manager discovered a 9.07-carat diamond at a state park in southwestern Arkansas after thinking the precious gem was a piece of glass.<br /><br />Kevin Kinard of Maumelle found the second-largest diamond in the 48-year history of Crater of Diamonds State Park on Labor Day, according to a news release from Arkansas State Parks.<br /><br />Kinard said he and his friends hauled sifting equipment to the state park in Murfreesboro. Kinard noted that he’s been visiting Crater of Diamonds regularly since he was a kid but had never stumbled upon a diamond until Sept. 7.<br /><br />“I only wet sifted for about ten minutes before I started walking up and down the plowed rows,” he said. “Anything that looked like a crystal, I picked it up and put it in my bag.”<br /><br />While searching in the southeast portion of the 37.5-acre diamond search area, Kinard scooped up a marble-sized crystal that had a rounded, dimpled shape.<br /></p><div style="margin: 0px auto; width: 100%;">
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</div><br />“It kind of looked interesting and shiny, so I put it in my bag and kept searching,” Kinard said. “I just thought it might’ve been glass.”<br /><br />Several hours later, Kinard said he and his comrades stopped by the park’s Diamond Discovery Center, where park workers identify visitor findings and register diamonds.<br /><br />“I almost didn’t have them check my finds, because I didn’t think I had found anything,” Kinard said. “My friend had hers checked, though, so I went ahead and had them check mine, too.”<p></p><p></p><p>The stone is the second-largest diamond ever found at the park, which opened in 1972 and is one of the only public diamond fields in the world. Crater of Diamonds has registered over 240 diamonds this year, according to the news release, and sees an average of about one or two diamonds per day. Visitors often bring their own tools to search the 37-acre diamond field, but they aren’t allowed to use battery or motor-powered tools.<br /><br />“A find like this is always thrilling for the park guest, as well as the park staff, who get to help identify the gem and share in the excitement,” Stacy Hurst, secretary of the Arkansas Department of Parks, Heritage and Tourism, said in the release.</p><p>The previous record for the second-largest diamond found at the park since its 1972 opening was an 8.82 carat white diamond found in 1981. In 2019, a Texas woman found a 3.72-carat yellow diamond at the park. The largest diamond ever found there is a 16.37-carat white diamond named Amarillo Starlight, which was unearthed in 1975. Assistant Superintendent Dru Edmonds said in the release, “Mr. Kinard’s diamond is very large, with a brandy brown color. It has a rounded, dewdrop shape and a metallic shine typical of all Crater diamonds.”<br /><br />Waymon Cox, park interpreter at Crater of Diamonds, told The Washington Post via email that the park employees “cannot determine a diamond’s value at the park,” but he noted that similarly sized finds have been estimated to be worth a fortune in the past. In 2015, for example, an 8.52-carat diamond found at the park was valued at around $1,000,000 after it was cut into a 4.63-carat triolette.<br /><br />Lucky visitors who do find diamonds are typically asked to name the stones, and Kinard named his in honor of friends who visited the park with him on Labor Day — the Kinard Friendship Diamond.<br /><br />“We love to travel together and had such a great time out here,” Kinard said of their trip to the park. “It was a very humbling experience.” </p><p><b><span style="font-family: Georgia, "Times New Roman", serif;"><a href="https://www.geologyin.com/2016/08/the-only-diamond-mine-in-world-where.html" target="_blank">The Only Diamond Mine In the World Where You Can Be the Miner</a></span></b></p><p></p><p><span style="font-size: medium;"><u><i>The above story is based on <a href="https://www.arkansasstateparks.com/articles/visitor-finds-9-carat-diamond-crater-diamonds-state-park" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.arkansasstateparks.com/" rel="nofollow" target="_blank">Arkansas State Parks</a>.</i></u></span><br /></p>

Arkansas Man Finds 9-carat Diamond at Crater of Diamonds State Park

Kevin Kinard was visiting Arkansas' Crater of Diamonds State Park when he discovered a 9.07 carat diamond. A bank manager discovered a...

Gold Miners Discover 100 Million-year-old Meteorite Crater Down Under

Earth History, Meteorite 6:23 PM

<p><br /></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><img alt="Gold miners discover 100 million-year-old meteorite crater Down Under" border="0" data-original-height="720" data-original-width="1280" height="360" src="https://1.bp.blogspot.com/-xprVp9VB_WA/X3nomq2_EPI/AAAAAAAASjg/MiCehjVY4dkp6gotaX8KJyo3qhObF0scwCLcBGAsYHQ/w640-h360/newly-discovered-crater%2B%25281%2529.jpg" style="margin-left: auto; margin-right: auto;" width="640" /></td></tr><tr><td class="tr-caption" style="text-align: center;">The newly discovered crater is thought to be five times bigger than Wolfe Creek Crater (pictured), one of the largest meteorite craters in the world. Credit: Dr Jayson Meyers<br /><br /></td></tr></tbody></table><p></p><div class="separator" style="clear: both; text-align: center;"></div><p></p><p>A massive 100 million-year-old meteorite crater has been found while a company was drilling for gold in outback Western Australia.<br /><br />The impact crater is estimated to have a diameter of about 5km. Although not visible from the surface, experts found the crater using electromagnetic surveys.<br /><br />Located near the Goldfields mining town of Ora Banda, north-west of Kalgoorlie-Boulder, the crater is believed to be five times bigger than the famous Wolfe Creek crater in the Kimberley.<br /><br />The geologist and geophysicist, Dr Jayson Meyers, said the find was significant and unexpected.<br /><br />“This discovery was made in an area where the landscape is very flat. You wouldn’t know it was there because the crater has been filled in over geological time,” he said.<br /><div style="width:100%;margin: 0px auto">
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</div><br />The crater was discovered on land owned by Australia’s third-largest gold-mining company, Evolution Mining.<br /><br />With a diameter of 5km, the Ora Banda crater is thought to be one of the largest meteorite craters in the world.<br /><br />Using modern techniques, such as gravity surveying, geologists were able to map out the crater and Meyers thinks their successful find will lead to more discoveries.<br /><br />“There’s probably quite a few more out there,” he said. “We’ve probably been hit by more asteroids than we thought. If we start recognising more of these, then the landscape begins changing, and we have to ask ourselves what’s the frequency and why are they happening?”<br /><br />Meyers said more discoveries could help scientists better predict when a meteorite may next strike Earth.<br /><br />“If we can understand more of the geological history, we can predict when the next event will happen, or see when another rogue asteroid could hit us.”<br /><br />Close inspections of drilling samples included telltale signs of a meteorite strike, including “shatter cones”, which are known to form in the bedrock below craters or underground nuclear explosions.<br /><br />Meyers hypothesises the meteorite had to have been quite large in diameter to cause such an impact.<br /><br />“To cause an impact of that size, the asteroid would’ve been approximately 100-200 metres in diameter, so it was a pretty big rock that came sailing into our planet. The ground was actually pushed down from the pressure, but then the Earth rebounded, almost like a spring. It bounced back up.”<br /><br />Scientists discovered the world’s oldest meteorite crater in Western Australia’s mid-west earlier this year.<br /><br />The Yarrabubba crater, located near Meekatharra in WA’s mid-west, was found to be around 2.23 billion years old. That makes it over 200 million years older than the next oldest crater. </p><p><br /></p><p><i><u>The above story is based on <a href="https://www.psi.edu/epo/explorecraters/shattercones.htm" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.psi.edu/" rel="nofollow" target="_blank">PSI</a>.</u></i><br /></p>

Gold Miners Discover 100 Million-year-old Meteorite Crater Down Under

The newly discovered crater is thought to be five times bigger than Wolfe Creek Crater (pictured), one of the largest meteorite craters in t...

Geology In