July 2021

Rock Crystals From the Deep Give Microscopic Clues to Earthquake Ground Movements

<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/-Axlgz1HjSdc/YPhWcU4-BHI/AAAAAAAATOI/f_locNcUy7cDwjpLJN3Rrl3e9l0PtjE2wCLcBGAsYHQ/s1149/rock-crystals-from-the%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="540" data-original-width="1149" height="300" src="https://1.bp.blogspot.com/-Axlgz1HjSdc/YPhWcU4-BHI/AAAAAAAATOI/f_locNcUy7cDwjpLJN3Rrl3e9l0PtjE2wCLcBGAsYHQ/w640-h300/rock-crystals-from-the%2B%25281%2529.jpg" title="Rock crystals from the deep give microscopic clues to earthquake ground movements" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Chunks of exotic green rocks from the mantle erupted from the San Carlos Volcanic Field, Arizona. Credit: James St John</td></tr></tbody></table> <br /></p><p>Microscopic imperfections in rock crystals deep beneath Earth’s surface play a deciding factor in how the ground slowly moves and resets in the aftermath of major earthquakes, says new research involving the University of Cambridge.<br /><br />The stresses resulting from these defects – which are small enough to disrupt the atomic building blocks of a crystal – can transform how hot rocks beneath Earth’s crust move and in turn transfer stress back to Earth’s surface, starting the countdown to the next earthquake. <br /><br />The new study, published in Nature Communications, is the first to map out the crystal defects and surrounding force fields in detail. “They’re so tiny that we’ve only been able to observe them with the latest microscopy techniques,” said lead author Dr David Wallis from Cambridge's Department of Earth Sciences, “But it’s clear that they can significantly influence how deep rocks move, and even govern when and where the next earthquake will happen.”<br /><br />By understanding how these crystal defects influence rocks in the Earth’s upper mantle, scientists can better interpret measurements of ground motions following earthquakes, which give vital information on where stress is building up - and in turn where future earthquakes may occur.<br /><div style="width:100%;margin: 0px auto">
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</div><br />Earthquakes happen when pieces of Earth’s crust suddenly slip past each other along fault lines, releasing stored-up energy which propagates through the Earth and causes it to shake. This movement is generally a response to the build-up of tectonic forces in the Earth’s crust, causing the surface to buckle and eventually rupture in the form of an earthquake.<br /><br />Their work reveals that the way Earth’s surface settles after an earthquake, and stores stress prior to a repeat event, can ultimately be traced to tiny defects in rock crystals from the deep.<br /><br />“If you can understand how fast these deep rocks can flow, and how long it will take to transfer stress between different areas across a fault zone, then we might be able to get better predictions of when and where the next earthquake will strike,” said Wallis.<br /><br />The team subjected olivine crystals – the most common component of the upper mantle -- to a range of pressures and temperatures in order to replicate conditions of up to 100 km beneath Earth’s surface, where the rocks are so hot (roughly 1250oC) they move like syrup.<br /><br />Wallis likens their experiments to a blacksmith working with hot metal – at the highest temperatures, their samples were glowing white-hot and pliable.<br /><br />They observed the distorted crystal structures using a high-resolution form of electron microscopy, called electron backscatter diffraction, which Wallis has pioneered on geological materials.<br /><br />Their results shed light on how hot rocks in the upper mantle can mysteriously morph from flowing almost like syrup immediately after an earthquake to becoming thick and sluggish as time passes.<br /><br />This change in thickness -- or viscosity – transfers stress back to the cold and brittle rocks in the crust above, where it builds up – until the next earthquake strikes.<br /><br />The reason for this switch in behaviour has remained an open question, “We’ve known that microscale processes are a key factor controlling earthquakes for a while, but it’s been difficult to observe these tiny features in enough detail,” said Wallis. “Thanks to a state-of-the-art microscopy technique, we’ve been able to look into the crystal framework of hot, deep rocks and track down how important these miniscule defects really are”.<br /><br />Wallis and co-authors show that irregularities in the crystals become increasingly tangled over time; jostling for space due to their competing force fields – and it’s this process that causes the rocks to become more viscous.<br /><br />Until now it had been thought that this increase in viscosity was because of the competing push and pull of crystals against each other, rather than being caused by microscopic defects and their stress fields inside the crystals themselves.<br /><br />The team hope to apply their work to improving seismic hazard maps, which are often used in tectonically active areas like southern California to estimate where the next earthquake will occur. Current models, which are usually based on where earthquakes have struck in the past, and where stress must therefore be building up, only take into account the more immediate changes across a fault zone and do not consider gradual stress changes in rocks flowing deep within the Earth.<br /><br />Working with colleagues at Utrecht University, Wallis also plans to apply their new lab constraints to models of ground movements following the hazardous 2004 earthquake which struck Indonesia, and the 2011 Japan quake – both of which triggered tsunamis and lead to the loss of tens of thousands of lives.<br /><br /></p><p><u><i><span style="font-family: trebuchet;">The above story is based on <a href="https://www.cam.ac.uk/research/news/rock-crystals-from-the-deep-give-microscopic-clues-to-earthquake-ground-movements" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.cam.ac.uk/" rel="nofollow" target="_blank">University of Cambridge. </a></span></i></u><br /></p>

Rock Crystals From the Deep Give Microscopic Clues to Earthquake Ground Movements

Chunks of exotic green rocks from the mantle erupted from the San Carlos Volcanic Field, Arizona. Credit: James St John Microscopic imperf...

Watermelon Tourmaline: What Is Watermelon Tourmaline?

gemstones, Mineralogy, Minerals 7:15 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;"><a href="https://1.bp.blogspot.com/-moIGXHHGp48/YPmW8eXpDEI/AAAAAAAATOY/jAn9rvsIIBwDfu4eU_1uNzxItrQfw7XoQCLcBGAsYHQ/s1035/What-is-Watermelon-Tourmaline-GeologyPage%2B%25281%2529.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="863" data-original-width="1035" height="334" src="https://1.bp.blogspot.com/-moIGXHHGp48/YPmW8eXpDEI/AAAAAAAATOY/jAn9rvsIIBwDfu4eU_1uNzxItrQfw7XoQCLcBGAsYHQ/w400-h334/What-is-Watermelon-Tourmaline-GeologyPage%2B%25281%2529.jpg" title="A slice of watermelon tourmaline" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">A slice of watermelon tourmaline<br /></td></tr></tbody></table> <br /><p></p><p style="text-align: left;"> Watermelon tourmaline is a variety of concentrically color-zoned tourmaline with red interiors and green exteriors and is distinct from longitudinal bi-color or polychrome zonation.<br /> <br />All colored Tourmaline gems display pleochroism, meaning their color changes when viewed at different angles. In some Tourmaline gems, this effect is hardly noticeable, while in others it is strongly apparent. Gemstone cutters must take this into account when cutting a Tourmaline, so that the finished gem brings out its best color.<br /></p><h4 style="text-align: left;">What does watermelon tourmaline look like?</h4><p style="text-align: left;">As the name suggests, watermelon tourmaline displays banded colours that resemble a ripe slice of watermelon. The red or pink centre is surrounded by a rim of green, often separated by a sliver of pale pink or white. The brightly coloured zones can also occur at either end of the gem although there is some debate as to whether these stones should be classified as watermelon or simply bi-colour tourmalines.<br /><br /></p><div style="margin: 0px auto; width: 100%;">
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</div><br />Watermelon tourmaline crystals tend to form with a distinctive rounded triangular shape, as demonstrated beautifully in this stunning pendant by Paula Crevoshay. Watermelon tourmalines with vivid, clearly separated colours are very rare and command high prices. Matthew Morrell says: “Clean stones with good crystal in the 4-7 carats range, with an even distribution of each colour, change hands in Europe at between $500-$600 per carat.”<br /><br />Cutting the stone into slices like a loaf of bread rather than faceting the rough often enhances the resemblance to a real watermelon. Their complex structure makes tourmalines very difficult to cut. A great deal of expertise is required to identify areas of tension within the stone, which can cause it to crack during the cutting process. <p></p><h4 style="text-align: left;">What causes watermelon tourmaline’s colours?</h4><p style="text-align: left;">The bi-coloured and multi-coloured zoning that we so often see in tourmaline gems happens when the trace elements change in concentration or composition during a crystal’s growth. These unique gems can have coloured zones across the length of the crystal, or they can have a core of one colour and an outer edge of another colour. A single tourmaline crystal can contain up to 15 different colours or shades – no wonder it has been nicknamed the “Rainbow Gem”.<br /><br />In watermelon tourmaline, pink and green Elbaite crystals are found in the same stone, and these colour zones provide a visual record of its formation process.<br /><br />As the watermelon tourmaline crystal grows and thickens, it is exposed to different minerals such as manganese and lithium, which cause the gem to change colour from a pink centre through a pale zone to the green rind.</p><p style="text-align: left;"><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/-P7y6PCiVbX8/YPmZQNDC95I/AAAAAAAATOg/JuG25VkCIYAIBpFfe-p3Wxxkf-clm522ACLcBGAsYHQ/s800/Watermelon-Tourmaline%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="800" data-original-width="800" height="400" src="https://1.bp.blogspot.com/-P7y6PCiVbX8/YPmZQNDC95I/AAAAAAAATOg/JuG25VkCIYAIBpFfe-p3Wxxkf-clm522ACLcBGAsYHQ/w400-h400/Watermelon-Tourmaline%2B%25281%2529.jpg" title="A slice of watermelon tourmaline" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">A slice of watermelon tourmaline</td></tr></tbody></table><br /></p><h4 style="text-align: left;">See also: </h4><p style="text-align: left;"><a href="https://www.geologyin.com/2018/04/tourmaline-species-and-color-varieties.html" target="_blank">Tourmaline: Species and Color Varieties</a><br /><a href="https://www.geologyin.com/2017/04/where-does-watermelon-tourmaline-come.html" target="_blank">Where Does Watermelon Tourmaline Come From?</a><br /><a href="https://www.geologyin.com/2017/02/why-fluorite-comes-in-different-colors.html" target="_blank">Why Fluorite Comes in Different Colors?</a><br /></p>

Watermelon Tourmaline: What Is Watermelon Tourmaline?

A slice of watermelon tourmaline Watermelon tourmaline is a variety of concentrically color-zoned tourmaline with red interiors and green...

Ancient 15,000-Year-Old Viruses Identified in Melting Tibetan Glaciers

News, Researches 6:48 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;"><a href="https://1.bp.blogspot.com/-R3CTc6XzGdc/YPhgssNiynI/AAAAAAAATOQ/7uWfpMh4zSQxp-SAwCk3Ci0BpkoAJxeJgCLcBGAsYHQ/s1467/Multiple-Bacteriophages-Attached-to-Bacterial-Cell-Wall%2B%25281%2529%2B%25281%2529.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="880" data-original-width="1467" height="384" src="https://1.bp.blogspot.com/-R3CTc6XzGdc/YPhgssNiynI/AAAAAAAATOQ/7uWfpMh4zSQxp-SAwCk3Ci0BpkoAJxeJgCLcBGAsYHQ/w640-h384/Multiple-Bacteriophages-Attached-to-Bacterial-Cell-Wall%2B%25281%2529%2B%25281%2529.jpg" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Bacteriophages on a bacterium. (Graham Beards/Wikimedia Commons/CC BY-SA 3.0)</td></tr></tbody></table> <br /><p></p><p>Scientists who study glacier ice have found viruses nearly 15,000 years old in two ice samples taken from the Tibetan Plateau in China. Most of those viruses, which survived because they had remained frozen, are unlike any viruses that have been cataloged to date.<br /><br />The findings, published today in the journal Microbiome, could help scientists understand how viruses have evolved over centuries. For this study, the scientists also created a new, ultra-clean method of analyzing microbes and viruses in ice without contaminating it.<br /><br />“These glaciers were formed gradually, and along with dust and gases, many, many viruses were also deposited in that ice,” said Zhi-Ping Zhong, lead author of the study and a researcher at The Ohio State University Byrd Polar and Climate Research Center who also focuses on microbiology. “The glaciers in western China are not well-studied, and our goal is to use this information to reflect past environments. And viruses are a part of those environments.”<br /></p><div style="margin: 0px auto; width: 100%;">
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</div><p><br />The researchers analyzed ice cores taken in 2015 from the Guliya ice cap in western China. The cores are collected at high altitudes – the summit of Guliya, where this ice originated, is 22,000 feet above sea level. The ice cores contain layers of ice that accumulate year after year, trapping whatever was in the atmosphere around them at the time each layer froze. Those layers create a timeline of sorts, which scientists have used to understand more about climate change, microbes, viruses and gases throughout history.<br /><br />Researchers determined that the ice was nearly 15,000 years old using a combination of traditional and new, novel techniques to date this ice core.<br /> </p><p>When they analyzed the ice, they found genetic codes for 33 viruses. Four of those viruses have already been identified by the scientific community. But at least 28 of them are novel. About half of them seemed to have survived at the time they were frozen not in spite of the ice, but because of it.<br /><br />“These are viruses that would have thrived in extreme environments,” said Matthew Sullivan, co-author of the study, professor of microbiology at Ohio State and director of Ohio State’s Center of Microbiome Science. “These viruses have signatures of genes that help them infect cells in cold environments – just surreal genetic signatures for how a virus is able to survive in extreme conditions. </p><p>These are not easy signatures to pull out, and the method that Zhi-Ping developed to decontaminate the cores and to study microbes and viruses in ice could help us search for these genetic sequences in other extreme icy environments – Mars, for example, the moon, or closer to home in Earth’s Atacama Desert.”<br /><br />Viruses do not share a common, universal gene, so naming a new virus – and attempting to figure out where it fits into the landscape of known viruses – involves multiple steps. To compare unidentified viruses with known viruses, scientists compare gene sets. Gene sets from known viruses are cataloged in scientific databases.<br /><br />Those database comparisons showed that four of the viruses in the Guliya ice cap cores had previously been identified and were from virus families that typically infect bacteria. The researchers found the viruses in concentrations much lower than have been found to exist in oceans or soil.<br /><br />The researchers’ analysis showed that the viruses likely originated with soil or plants, not with animals or humans, based on both the environment and the databases of known viruses.<br /><br />The study of viruses in glaciers is relatively new: Just two previous studies have identified viruses in ancient glacier ice. But it is an area of science that is becoming more important as the climate changes, said Lonnie Thompson, senior author of the study, distinguished university professor of earth sciences at Ohio State and senior research scientist at the Byrd Center.<br /><br />“We know very little about viruses and microbes in these extreme environments, and what is actually there,” Thompson said. “The documentation and understanding of that is extremely important: How do bacteria and viruses respond to climate change? What happens when we go from an ice age to a warm period like we’re in now?”<br /><br />This study was an interdisciplinary effort between Ohio State’s Byrd Center and its Center for Microbiome Science. The 2015 Guliya ice cores were collected and analyzed as part of a collaborative program between the Byrd Polar and Climate Research Center and the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences, funded by the U.S. National Science Foundation and the Chinese Academy of Sciences. Funding also came from the Gordon and Betty Moore Foundation and the U.S. Department of Energy.<br /><br />A close look at the newly cleaned ice cores revealed the presence of 33 groups of virus genera, 28 of which are not known to modern science. The researchers noted that the viruses they found in the cores from the two sites differed from one another, likely because they represented different points in time and thus differences in climate. They note that their work might grow in importance as the planet heats up due to global warming and melts glaciers, possibly unleashing deadly viruses.<br /><br /> </p><p></p><p><u><i><span style="font-family: trebuchet;"> The above story is based on <a href="https://news.osu.edu/15000-year-old-viruses-discovered-in-tibetan-glacier-ice/" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.osu.edu/" rel="nofollow" target="_blank">The Ohio State University.</a></span></i></u></p>

Ancient 15,000-Year-Old Viruses Identified in Melting Tibetan Glaciers

Bacteriophages on a bacterium. (Graham Beards/Wikimedia Commons/CC BY-SA 3.0) Scientists who study glacier ice have found viruses nearly 1...

Rare Diamonds Show Life-Giving Elements Present on Earth Soon After It Formed

Diamonds, Earth History, Geochemistry 7:50 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/-rKHxiqKq0Us/YPG3-Msg4NI/AAAAAAAATNw/cTLYHVkgEwwmOQrK7Q69m8dd0fRcsj47ACLcBGAsYHQ/s1352/Rare%2Bdiamonds%2Bshow%2Blife-giving%2Belements%2Bpresent%2Bon%2BEarth%2Bsoon%2Bafter%2Bit%2Bformed%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1014" data-original-width="1352" height="480" src="https://1.bp.blogspot.com/-rKHxiqKq0Us/YPG3-Msg4NI/AAAAAAAATNw/cTLYHVkgEwwmOQrK7Q69m8dd0fRcsj47ACLcBGAsYHQ/w640-h480/Rare%2Bdiamonds%2Bshow%2Blife-giving%2Belements%2Bpresent%2Bon%2BEarth%2Bsoon%2Bafter%2Bit%2Bformed%2B%25281%2529.jpg" title="One of the 2.7 billion year-old diamonds used in this work. Credit: Michael Broadley" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">One of the 2.7 billion year-old diamonds used in this work. Credit: Michael Broadley<br /></td></tr></tbody></table> <br /></p><p><span style="font-family: georgia;">Earth's atmosphere was primed for an 'explosion' in the diversity of life as early as 2.7 billion years ago, a study of ancient diamonds has revealed. </span><br /></p><p>A unique study of ancient diamonds has shown that the basic chemical composition of the Earth's atmosphere which makes it suitable for life's explosion of diversity was laid down at least 2.7 billion years ago. Volatile gases conserved in diamonds found in ancient rocks were present in similar proportions to those found in today's mantle, which in turn indicates that there has been no fundamental change in the proportions of volatiles in the atmosphere over the last few billion years. This shows that one of the basic conditions necessary to support life, the presence of life-giving elements in sufficient quantity, appeared soon after Earth formed, and has remained fairly constant ever since.<br /><br />Presenting the work at the Goldschmidt Geochemistry conference, lead researcher Dr Michael Broadly said, "The proportion and make-up of volatiles in the atmosphere reflects that found in the mantle, and we have no evidence of a significant change since these diamonds were formed 2.7 billion years ago".<br /><div style="width:100%;margin: 0px auto">
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</div><br />Volatiles, such as hydrogen, nitrogen, neon, and carbon-bearing species are light chemical elements and compounds, which can be readily vaporised due to heat, or pressure changes. They are necessary for life, especially carbon and nitrogen. Not all planets are rich in volatiles; Earth is volatile rich, as is Venus, but Mars and the Moon lost most of their volatiles into space. Generally, a planet rich in volatiles has a better chance of sustaining life, which is why much of the search for life on planets surrounding distant stars (exoplanets) has focused on looking for volatiles.<br /><br />On Earth, volatile substances mostly bubble up from the inside of the planet, and are brought to the surface through such things as volcanic eruptions. Knowing when the volatiles arrived in the Earth's atmosphere is key to understanding when the conditions on Earth were suitable for the origin and development of life, but until now there has been no way of understanding these conditions in the deep past.<br /><br />Now French and Canadian researchers have used ancient diamonds as a time capsule, to examine the conditions deep inside the Earth's mantle in the distant past. Studies of the gases trapped in these diamonds show that the volatile composition of the mantle has changed little over the last 2.7 billion years.<br /><br />Lead researcher, Michael Broadley (University of Lorraine, France) said "Studying the composition of the Earth's modern mantle is relatively simple. On average the mantle layer begins around 30km below the Earth's surface, and so we can collect samples thrown up by volcanoes and study the fluids and gases trapped inside. However, the constant churning of the Earth's crust via plate tectonics means that older samples have mostly been destroyed. Diamonds however, are comparatively indestructible, they're ideal time capsules".<br /><br />We managed to study diamonds trapped in 2.7 billion year old highly preserved rock from Wawa, on Lake Superior in Canada. This means that the diamonds are at least as old as the rocks they are found in - probably older. It's difficult to date diamonds, so this gave us a lucky opportunity to be sure of the minimum age. These diamonds are incredibly rare, and are not like the beautiful gems we think of when we think of diamonds. We heated them to over 2000 C to transform them into graphite, which then released tiny quantities of gas for measurement".<br /><br />The team measured the isotopes of Helium, Neon, and Argon, and found that they were present in similar proportions to those found in the upper mantle today. This means that there has probably been little change in the proportion of volatiles generally, and that the distribution of essential volatile elements between the mantle and the atmosphere are likely to have remained fairly stable throughout the majority of Earth's life. The mantle is the part between the Earth's crust and the core, it comprises around 84% of the Earth's volume.<br /><br />Dr Broadley continued "This was a surprising result. It means the volatile-rich environment we see around us today is not a recent development, so providing the right conditions for life to develop. Our work shows that these conditions were present at least 2.7 billion years ago, but the diamonds we use may be much older, so it's likely that these conditions were set well before our 2.7 billion year threshold".<br /><br /> </p><p><u><i>The above story is based on <a href="https://2021.goldschmidt.info/goldschmidt/2021/meetingapp.cgi" rel="nofollow" target="_blank">materials </a>provided by<a href="https://2021.goldschmidt.info/goldschmidt/2021/meetingapp.cgi" rel="nofollow" target="_blank"> Goldschmidt Conference.</a> </i></u><br /></p>

Rare Diamonds Show Life-Giving Elements Present on Earth Soon After It Formed

One of the 2.7 billion year-old diamonds used in this work. Credit: Michael Broadley Earth's atmosphere was primed for an 'explosi...

“Invisible” Gold – Fool’s Gold Actually Contains Real Gold

Geochemistry, Geology, Mining 7:13 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;"><a href="https://1.bp.blogspot.com/-GTECD4V30EM/YO8L9TMGlPI/AAAAAAAATNM/F84MgWB9jFcIiSFkVNzLahIV6tAjCuh6QCLcBGAsYHQ/s1280/Fool%25E2%2580%2599s%2BGold%2BActually%2BContains%2BReal%2BGold%2B%25281%2529.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="933" data-original-width="1280" height="291" src="https://1.bp.blogspot.com/-GTECD4V30EM/YO8L9TMGlPI/AAAAAAAATNM/F84MgWB9jFcIiSFkVNzLahIV6tAjCuh6QCLcBGAsYHQ/w400-h291/Fool%25E2%2580%2599s%2BGold%2BActually%2BContains%2BReal%2BGold%2B%25281%2529.jpg" title="Pyrite with Quartz - Huanzala Mine, Huallanca District, Dos de Mayo Province, Huánuco Department Peru" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Pyrite with Quartz - Huanzala Mine, Huallanca District, Dos de Mayo Province, Peru<br />Photo: Fabre Minerals<br /></td></tr></tbody></table> <br /><p></p><p>Confirming once more that it cannot be trusted, the metal known as fool’s gold, aka pyrite, can contain bits of the real thing, according to an Australian-Chinese research team. Getting at the trapped gold, however, is likely to be more trouble than it’s worth.</p><p>Curtin University research has found tiny amounts of gold can be 
trapped inside pyrite, commonly known as "fool's gold," which would make
 it much more valuable than its name suggests.<br /><br />This study, 
published in the journal Geology in collaboration with the University of
 Western Australia and the China University of Geoscience, provides an 
in-depth analysis to better understand the mineralogical location of the
 trapped gold in pyrite, which may lead to more environmentally friendly
 gold extraction methods.<br /><br />Lead researcher Dr Denis Fougerouse 
from Curtin’s School of Earth and Planetary Sciences said this new type 
of “invisible” gold has not previously been recognised and is only 
observable using a scientific instrument called an atom probe.<br /></p><div style="margin: 0px auto; width: 100%;">
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</div><br />“The
 discovery rate of new gold deposits is in decline worldwide with the 
quality of ore degrading, parallel to the value of precious metal 
increasing,” Dr Fougerouse said.<br /><br />“Previously gold extractors have
 been able to find gold in pyrite either as nanoparticles or as a 
pyrite-gold alloy, but what we have discovered is that gold can also be 
hosted in nanoscale crystal defects, representing a new kind of 
“invisible” gold.<br /><br />“The more deformed the crystal is, the more 
gold there is locked up in defects. The gold is hosted in nanoscale 
defects called dislocations – one hundred thousand times smaller than 
the width of a human hair – so a special technique called atom probe 
tomography is needed to observe it.”<br /><br />Dr Fougerouse said the team 
also explored gold extraction methods and possible ways to obtain the 
trapped gold with less adverse impacts on the environment.<br /><br />“Generally,
 gold is extracted using pressure oxidizing techniques (similar to 
cooking), but this process is energy hungry. We wanted to look into an 
eco-friendlier way of extraction,” Dr Fougerouse said.<br /><br />“We looked
 into an extraction process called selective leaching, using a fluid to 
selectively dissolve the gold from the pyrite. Not only do the 
dislocations trap the gold, but they also behave as fluid pathways that 
enable the gold to be “leached” without affecting the entire pyrite.”<br /><p></p><p>In a Conversation article accompanying the paper’s release, Fougerouse wrote that it was previously suspected that bits of gold in pyrite crystals came about at different times, and the two minerals glommed together later on. </p><p>The pyrite specimen the team inspected suggested that the two minerals can crystallize simultaneously, in a single process. Fougerouse also noted that different methods could be used to release the gold particles from their pyrite prison, which could be more energy efficient than the typical means of gold extraction, reactor-based oxidation, or smaller-scale methods like separating the gold from slag by smelting the ore. <br /></p><p>The
 study is supported by the Australian Research Council and the Science 
and Industry Endowment Fund. Dr Fougerouse is affiliated with The 
Institute for Geoscience Research (TIGeR), Curtin’s flagship Earth 
Sciences research institute. </p><p><br /></p><span style="font-family: trebuchet;"><i><u>The above story is based on <a href="https://research.curtin.edu.au/story/curtin-research-finds-fools-gold-not-so-foolish-after-all/" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.curtin.edu.au/" rel="nofollow" target="_blank">Curtin University.</a></u></i></span><p> </p>

“Invisible” Gold – Fool’s Gold Actually Contains Real Gold

Pyrite with Quartz - Huanzala Mine, Huallanca District, Dos de Mayo Province, Peru Photo: Fabre Minerals Confirming once more that it cann...

World’s First Nuclear Bomb Test Created Rare, Otherworldly Crystal

Geochemistry, Geology, Researches 7:37 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/-IsPSMtvHqj0/YOsdmrR8CKI/AAAAAAAATL8/IjZ3vpX1fl8ODhnYkvduWt5XHifCQ9C0QCLcBGAsYHQ/s1550/This%2Bsample%2Bof%2Bred%2Btrinitite%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="838" data-original-width="1550" height="346" src="https://1.bp.blogspot.com/-IsPSMtvHqj0/YOsdmrR8CKI/AAAAAAAATL8/IjZ3vpX1fl8ODhnYkvduWt5XHifCQ9C0QCLcBGAsYHQ/w640-h346/This%2Bsample%2Bof%2Bred%2Btrinitite%2B%25281%2529.jpg" title="This sample of red trinitite" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">This sample of red trinitite. Image credit:  @TrinititeMan On Twitter.<br /></td></tr></tbody></table> <br /></p><p><i>Newly Discovered Quasicrystal – “Magnificent in Its Complexity” – Was Created by the First Nuclear Explosion at Trinity Site</i><br /></p><p>A
 newly discovered quasicrystal that was created by the first nuclear 
explosion at Trinity Site, N.M., on July 16, 1945, could someday help 
scientists better understand illicit nuclear explosions and curb nuclear
 proliferation.<br /><br /> In an instant, a metal-coated plutonium device 
named "Gadget" imploded, creating a gargantuan fireball that rose high 
into the sky, vaporizing everything it touched. Sand melted into 
radioactive glass, and a crater nearly as wide as a football field 
dented the planet. The test — codenamed Trinity — was a success.<br /><br />But Trinity didn't just destroy; it also left something strange and new behind.<br /><div style="width:100%;margin: 0px auto">
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</div><br />In
 a study published in the journal Proceedings of the National Academy of
 Sciences, researchers have detected otherworldly crystals called 
"quasicrystals" trapped in the bomb-blasted rocks at the Trinity site. 
These odd gems, which lack the perfect symmetry of true crystals, are 
usually only seen in meteorites from the early solar system, and are 
thought to be forged only in the extreme heat and pressure of the 
universe's most powerful explosions.<br /><br />These newfound crystals, 
embedded in the rubble of the Trinity site, provide scientists with 
proof that quasicrystals can also result from mankind's most explosive 
creations, according to the study authors. These crystals give nuclear 
researchers "a new tool in the toolbox" for analyzing the power and 
impact of past nuclear explosions, both in the U.S. and abroad, study 
co-author Terry Wallace, director emeritus of Los Alamos National 
Laboratory in New Mexico, said in a video accompanying the research.<br /><br />"Understanding
 another country's nuclear weapons requires that we have a clear 
understanding of their nuclear testing programs," Wallace said in a 
statement. "We typically analyze radioactive debris and gases to 
understand how the weapons were built or what materials they contained, 
but those signatures decay. A quasicrystal that is formed at the site of
 a nuclear blast … [will] exist forever."<br /><br />When the plutonium 
Gadget detonated on July 16, the resulting fireball was hotter than 
Earth's sun, Wallace said. The heat and force of this explosion were so 
strong that the metal test tower and surrounding sand melted together 
into a new type of glass, later named trinitite.<br /><br />Most trinitite 
samples are green, like a pale glass bottle. But rarer samples are red, 
presumably because they contain greater amounts of copper and other 
metals from the test tower and recording equipment at the site. In their
 new study, Wallace and his colleagues examined a red trinitite specimen
 under an electron microscope, looking specifically at metallic "blobs" 
that might contain crystals.<br /><br />In this sample, the team detected a 
five-sided quasicrystal with an atomic structure never seen on Earth 
before. The crystal was made predominantly of silicon from the desert 
sand, but also contained proportionally high amounts of copper, plus 
some iron and calcium. The crystal is "magnificent in its complexity," 
Wallace said — and it's still not clear to his team exactly how or why 
it formed this way.<br /><br />One thing is clear, though: This quasicrystal
 has an "unmistakable" origin, based on its composition, radioactivity 
and discovery location, the researchers said. It's a unique crystal 
forged in the fires of America's first nuclear blast, and therefore is 
the oldest human-made quasicrystal on Earth.<br /><br />Similar crystals 
could lurk in the rubble of other nuclear test sites — and studying the 
unique structures of those crystals could reveal important information 
about the nature of the bombs that created them, Wallace said. Unlocking
 that knowledge will require a lot more study — and many more crystal 
samples — but ultimately, it will be worth it to better understand the 
cosmic-level explosions that humans have learned to unleash here on 
Earth. </p><p><br /></p><u><i>The above story is based on <a href="https://www.pnas.org/content/118/22/e2101350118" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.pnas.org/" rel="nofollow" target="_blank">PNAS</a>.</i></u>

World’s First Nuclear Bomb Test Created Rare, Otherworldly Crystal

This sample of red trinitite. Image credit: @TrinititeMan On Twitter. Newly Discovered Quasicrystal – “Magnificent in Its Complexity” – W...

'Icelandia': Is Iceland the Tip of a Vast, Sunken Continent?

earth, Geology 6:20 PM

<p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://1.bp.blogspot.com/-2kxuzPWRDy0/YOcTdibx21I/AAAAAAAATL0/c2aKdaJeb_AmLNsqQgDRanAvI24-E59bgCLcBGAsYHQ/s1280/%2527Icelandia%2527%2BIs%2BIceland%2Bthe%2BTip%2Bof%2Ba%2BVast%252C%2BSunken%2BContinent%2B%25281%2529.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="720" data-original-width="1280" height="225" src="https://1.bp.blogspot.com/-2kxuzPWRDy0/YOcTdibx21I/AAAAAAAATL0/c2aKdaJeb_AmLNsqQgDRanAvI24-E59bgCLcBGAsYHQ/w400-h225/%2527Icelandia%2527%2BIs%2BIceland%2Bthe%2BTip%2Bof%2Ba%2BVast%252C%2BSunken%2BContinent%2B%25281%2529.jpg" title="'Icelandia': Is Iceland the Tip of a Vast, Sunken Continent?" width="400" /></a></div> <br /><p></p><p>Academics believe they have identified a remarkable geological secret: A sunken continent hidden under Iceland and the surrounding ocean,which they have dubbed "Icelandia."<br /><br />An international team of geologists, led by Gillian Foulger, Emeritus Professor of Geophysics in the Department of Earth Sciences at Durham University (UK), believe the sunken continent could stretch from Greenland all the way to Europe.<br /><br />It is believed to cover an area of ~600,000 km2 but when adjoining areas west of Britain are included in a "Greater Icelandia," the entire area could be ~1,000,000 km2 in size.<br /><br />If proven, it means that the giant supercontinent of Pangaea, which is thought to have broken up over 50 million years ago, has in fact not fully broken up.<div style="width:100%;margin: 0px auto">
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</div>This new theory challenges long-held scientific ideas around the extent of oceanic and continental crust in the North Atlantic region, and how volcanic islands, like Iceland, formed.<br /><br />The presence of continental—rather than oceanic—crust could also spark discussions about a new source of minerals and hydrocarbons, both of which are contained in continental crust.<br /><br />The revolutionary new theory was born from an innovative series of expert meetings held in Durham and is included in a dedicated chapter of In the Footsteps of Warren B. Hamilton: New Ideas in Earth Science (published 29 June 2021 by the Geological Society of America), which Professor Foulger has co-written with Dr. Laurent Gernigon of the Geological Survey of Norway and Professor Laurent Geoffroy of the Ocean Geosciences Laboratory, University of Brest (France).<br /><br />Speaking about the new theory, Professor Foulger said, "Until now Iceland has puzzled geologists, as existing theories that it is built of and surrounded by oceanic crust are not supported by multiplegeological data. For example, the crust under Iceland is over 40 km thick—seven times thicker than normal oceanic crust. This simply could not be explained.<br /><br />"However, when we considered the possibility that this thick crust is continental, our data suddenly all made sense. This led us immediately to realize that the continental region was much bigger than Iceland itself—there is a hidden continent right there under the sea.<br /><br />"There is fantastic work to be done to prove the existence of Icelandia but it also opens up a completely new view of our geological understanding of the world. Something similar could be happening at many more places.<br /><br />"We could eventually see maps of our oceans and seas being redrawn as our understanding of what lies beneath changes."<br /><br />The research team is now working with collaborators from across the globe on work to test their theory, which will begin once COVID-19 restrictions allow.<br /><br />This work could involve electrical conductivity surveys, and the collection of zircon crystals in Iceland and elsewhere. Other tests such as seismic profiling and drilling would need millions of pounds to fund, but such is the importance of this work that funding may well be forthcoming.<br /><br />Professor Foulger is a world-leading geologist whose research has contributed to mapping the geological composition of the seabed in relation to continental land masses.<br /><br />This work has important legal and political ramifications, as under certain conditions, the United Nations Convention on the Law of the Sea grants coastal states exclusive rights to the non-living resources of their adjacent seabed if scientists can prove that the seabed is a submerged extension of the continental landmass.<br /><br />Professor Philip Steinberg, Director of IBRU, Durham University's Centrefor Borders Research, noted, "Countries around the world are spending enormous resources conducting subsea geologic research in order to identify their continental shelves and claim exclusive mineral rights there.<br /><br />"Research like Professor Foulger's, which forces us to rethink the relationship between seabed and continental geology, can have far-reaching impact for countries trying to determine what area of the seabed are their exclusive preserve and what areas are to be governed by the International Seabed Authority as the 'common heritage of humankind." </p><p><br /></p><p><u><i>The above story is based on <a href="https://pubs.geoscienceworld.org/books/book/2323/chapter/130412282/Icelandia" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.geosociety.org/" rel="nofollow" target="_blank">Geological Society of America.</a></i></u><br /></p>

'Icelandia': Is Iceland the Tip of a Vast, Sunken Continent?

Academics believe they have identified a remarkable geological secret: A sunken continent hidden under Iceland and the surrounding ocean,w...

Researchers Discover Why Gold Is Concentrated Alongside Arsenic

Geochemistry, Gold 8:20 PM

<p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://1.bp.blogspot.com/-EkJwQIKqF_o/YOM_EPTCucI/AAAAAAAATLo/fZZBxoNTF0EIysUFvtyvKLYajWafHPklQCLcBGAsYHQ/s1106/Researchers%2BDiscover%2BWhy%2BGold%2BIs%2BConcentrated%2BAlongside%2BArsenic%2B%25281%2529.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="533" data-original-width="1106" height="308" src="https://1.bp.blogspot.com/-EkJwQIKqF_o/YOM_EPTCucI/AAAAAAAATLo/fZZBxoNTF0EIysUFvtyvKLYajWafHPklQCLcBGAsYHQ/w640-h308/Researchers%2BDiscover%2BWhy%2BGold%2BIs%2BConcentrated%2BAlongside%2BArsenic%2B%25281%2529.jpg" title="Researchers Discover Why Gold Is Concentrated Alongside Arsenic" width="640" /></a></div> <br /><p></p><p>Why are gold deposits found at all? Gold is famously unreactive, and there seems to be little reason why gold should be concentrated, rather than uniformly scattered throughout the Earth’s crust. Now an international group of geochemists have discovered why gold is concentrated alongside arsenic, explaining the formation of most gold deposits. This may also explain why many gold miners and others have been at risk from arsenic poisoning. This work is presented at the Goldschmidt conference, after recent publication.<br /><br />Gold is prized for its purity and stability. It's also rare enough to retain its value—the World Gold Council estimates that all the gold ever mined in the world would fit into a 20 x 20 x 20-meter cube. Additionally, because it is one of the most inert metals in the whole periodic table, it doesn't easily react with other substances. So why should gold come together in sufficient quantity to mine—in other words, why do gold deposits exist?<br /><br />Some gold is found as gold nuggets, but an appreciable amount is bound up with minerals. Gold is known to be related to iron- and arsenic-containing minerals, such as pyrite and arsenopyrite. These minerals act sort of like a sponge, and are capable of concentrating gold up to 1 million times more than is found elsewhere in nature, such as in the hot spring waters that transport gold. This gold becomes chemically bound in these minerals, so it is invisible to the naked eye.<div style="width:100%;margin: 0px auto">
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</div>The scientific team studied the action of the gold-concentrating minerals using the intense X-rays beam produced by the European Synchrotron (ESRF) at Grenoble in France, which can probe the chemical bonds between the mineral and gold.<br /><br />They found that when the mineral is enriched with arsenic, gold can enter mineral structural sites by directly binding to arsenic (forming, chemically speaking, Au(2+) and As(1-) bonds), which allows gold to be stabilised in the mineral. However, when the arsenic concentration is low, gold doesn't enter the mineral structure but only forms weak gold-sulfur bonds with the mineral surface.<br /><br />Lead researcher, Dr. Gleb Pokrovski, directeur de recherche at CNRS, GET-CNRS-University of Toulouse Paul Sabatier, said, "Our results show that arsenic drives the concentration of gold. This arsenic-driven gold pump explains how these iron sulfides can massively capture and then release gold, so controlling ore deposit formation and distribution. In practical terms, it means that it will make it easier to find new sources of gold and other precious metals, which bind to arsenic-containing iron sulfides. It may also open the door to controlling the chemical reactions, and if we can improve gold processing, we can recover more gold."<br /><br />The new model identifies just why gold tends to be found with arsenic. Dr. Pokrovski said, "It has been known for centuries that gold is found with arsenic, and this has caused severe health problems for gold miners. Now we know what happens at an atomic level, we can begin to see if there's anything we can do to prevent this."<br /><br />The noxious link between arsenic and gold is well-known in France and elsewhere in the world, including at the Salsigne mine near Carcassonne. This was one of Western Europe's largest gold mines, and the world's largest arsenic producer at one time. It closed in 2004, but the environmental consequences of the arsenic pollution still persist in the region.<br /><br />Dr. Jeffrey Hedenquist, University of Ottawa, said, "Geologists as well as prospectors have long known that gold can be associated with arsenic-rich minerals, and over the past few decades, others have quantified this association. The findings of Dr. Pokrovski and his team now help to explain why we see this association, caused by an atomic-scale attraction between gold and arsenic, with this marriage arranged by the structure of certain minerals."<br /><br /></p><p><br /><u><i>The above story is based on materials provided by <a href="https://goldschmidt.info/2016/" rel="nofollow" target="_blank">Goldschmidt Geochemistry Conference.</a></i></u></p>

Researchers Discover Why Gold Is Concentrated Alongside Arsenic

Why are gold deposits found at all? Gold is famously unreactive, and there seems to be little reason why gold should be concentrated, rath...

This Tiny, 120-Million-Year-Old Fossil Has a T. Rex-Like Skull on a Bird Body

evolution, extinction, Fossils 7:21 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/-UowGEjak6pw/YN88l3I6skI/AAAAAAAATLE/u5Gji1uly4wha_UrW4VzDNEsUnfE0aBjQCLcBGAsYHQ/s1280/This%2BTiny%252C%2B120-Million-Year-Old%2BFossil%2BHas%2Ba%2BT.%2BRex-Like%2BSkull%2Bon%2Ba%2BBird%2BBody.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="906" data-original-width="1280" height="283" src="https://1.bp.blogspot.com/-UowGEjak6pw/YN88l3I6skI/AAAAAAAATLE/u5Gji1uly4wha_UrW4VzDNEsUnfE0aBjQCLcBGAsYHQ/w400-h283/This%2BTiny%252C%2B120-Million-Year-Old%2BFossil%2BHas%2Ba%2BT.%2BRex-Like%2BSkull%2Bon%2Ba%2BBird%2BBody.jpg" title="This Tiny, 120-Million-Year-Old Fossil Has a T. Rex-Like Skull on a Bird Body" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">The new bird fossil. (Min Wang)</td></tr></tbody></table> <br /></p><p>A tiny, 120 million-year-old fossil, discovered in northeast China, is neither bird nor dinosaur but is perched on its own evolutionary branch, somewhere in between.<br /><br />Researchers from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences have discovered a 120-million-year-old partial fossil skeleton of a tiny extinct bird that fits in the palm of the hand and preserves a unique skull with a mix of dinosaurian and bird features.<br /><br />The two-centimeter-long (0.75 inch) skull of the fossil shares many structural and functional features with the gigantic Tyrannosaurus rex, indicating that early birds kept many features of their dinosaurian ancestors and their skulls functioned much like those of dinosaurs rather than living birds.<br /><br />The bird was deposited 120 million years ago in a shallow lake in what is today Liaoning Province in northeastern China.<br /><br />Through detailed reconstruction of the bird family tree, the researchers demonstrated that the new fossil bird species belongs to an extinct group of birds called enantiornithines, or "opposite birds." They are the most diverse group of birds from the time of the dinosaurs in the Cretaceous and have been found all over the world.<br /><br />In living birds, the quadrate is one of the most movable bones in the skull and allows for the unique feature of living birds known as "kinetic skull," which allows the upper jaw to move independently of the brain and the lower jaw.<br /><br />In contrast with living birds, however, the skull of this new "opposite bird", as well as those of dinosaurs like Tyrannosaurus rex and the close dinosaurian relatives of birds (e.g., troodontids and dromaeosaurs), is not kinetic. Instead, its bones are "locked up" and unable to move.<br /><br />The temporal regions (sides) of the skull of this bird fossil are very different from living birds. This new species has two bony arches for jaw muscle attachment like those found in reptiles such as lizards, alligators, and dinosaurs, making the rear of the skull rigid and resistant to movement among the bones.<br /><br />"When reconstructing all parts of the skull three-dimensionally from the high resolution CT scans of the fossil, I had a problem figuring out one bone in particular," said Dr. WANG Min, the lead and corresponding author of the study. He said his colleague Dr. Thomas Stidham proposed that the bone was the pterygoid and looked "exactly like that of the dromaeosaur Linheraptor." The fossil has the first well-preserved pterygoid bone found in an early bird.<br /><br />The researchers compared CT scans of the bird skull to scans of the skull of the well-known dromaeosaur Linheraptor from Inner Mongolia, China. The results showed that many other features of the rear portion of the skull, including the shape of the basisphenoid bone and its connections with other skull bones, also resemble dromaeosaurs rather than living birds.<br /><br />"The fossil bird and dinosaurs also lack the discrete contact between the pterygoid and quadrate near the palate that is used in skull kinesis in living birds. In combination with the 'locked up' temporal bones, the difference in the palate structure also points to the absence of kinesis among early birds," said Dr. Stidham, co-author of the study.<br /><br />Furthermore, the team's discovery and meticulous anatomical research help to reinforce the already well-supported contention, based on many different lines of evidence, that birds are not only living dinosaurs, but evolved from the branch of dinosaurs that includes troodontids and dromaeosaurs like the "four-winged" Microraptor and swift Velociraptor.<br /><br />"Having a 'dinosaur' skull on a bird body certainly did not stop the enantiornithines, or other early birds, from being highly successful in places all around the world for tens of millions of years during the Cretaceous," said Dr. WANG.<br /></p><p><br /><i><u> The above story is based on <a href="https://english.cas.cn/newsroom/research_news/life/202106/t20210624_273072.shtml" rel="nofollow" target="_blank">materials </a>provided by <a href="http://english.ivpp.cas.cn/" rel="nofollow" target="_blank">Institute of Vertebrate Paleontology and Paleoanthropology.</a></u></i></p>

This Tiny, 120-Million-Year-Old Fossil Has a T. Rex-Like Skull on a Bird Body

The new bird fossil. (Min Wang) A tiny, 120 million-year-old fossil, discovered in northeast China, is neither bird nor dinosaur but is pe...

Geology In