November 2021

Woman Finds 4.38-carat Diamond at Arkansas' Crater of Diamonds State Park

<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/-j7jNJNQA0H0/YZ_F5-3RZ5I/AAAAAAAATaY/cz0F1L5mRWc4ickP3xUy5d0VdPFVCdMbACLcBGAsYHQ/s1200/Woman%2BFinds%2B4.38-carat%2BDiamond%2Bat%2BArkansas%2527%2BCrater%2Bof%2BDiamonds%2BState%2BPark%2B%25281%2529.jpg" 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/-j7jNJNQA0H0/YZ_F5-3RZ5I/AAAAAAAATaY/cz0F1L5mRWc4ickP3xUy5d0VdPFVCdMbACLcBGAsYHQ/w640-h426/Woman%2BFinds%2B4.38-carat%2BDiamond%2Bat%2BArkansas%2527%2BCrater%2Bof%2BDiamonds%2BState%2BPark%2B%25281%2529.jpg" title="The Lucy Diamond discovered by Noreen Wredberg at Crater of Diamonds State Park in Murfreesboro, Arkansas. Photo courtesy of Arkansas State Parks." width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">The Lucy Diamond discovered by Noreen Wredberg at Crater of Diamonds State Park in Murfreesboro, Arkansas. Photo courtesy of Arkansas State Parks. </td></tr></tbody></table>  Finders Keepers! A Lucky Retiree Visited an Arkansas National Park and Discovered a 4.38-Carat, Jellybean-Sized DiamondNoreen Wredberg and her husband, Michael, weren't really expecting to find anything at Arkansas' Crater of Diamonds State Park, she said, and she wasn't sure what she had found when she picked up a stone. A Northern California couple found a 4.38-carat yellow diamond while visiting Arkansas, making it the biggest piece of bling found this year at a state park known for yielding the shiny stones. Noreen and Michael Wredberg took a trip to two national parks in Arkansas last month, then decided on a whim to travel an hour south to Crater of Diamonds State Park in Murfreesboro. About 40 minutes into their walk, Noreen saw something sparkly on the ground. "I didn't know it was a diamond then, but it was clean and shiny, so I picked it up," she told park officials, according to a news release. "We really didn't think we would find one, let alone something that big." Since retiring in 2011, Noreen and her husband Michael have spent much of their leisure time traveling and visiting America’s National Parks. During a recent stop at Hot Springs National Park in Arkansas, Noreen realized that they were also close to another destination she had long wanted to visit, Crater of Diamonds State Park. <div style="margin: 0px auto; width: 100%;">
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</div> “I first saw the park featured on a TV show several years ago,” she said. “When I realized we weren’t too far away, I knew we had to come!” “Arkansas is the only state in the country that has a diamond mine open to the public,” said Arkansas Department of Parks, Heritage and Tourism Secretary Stacy Hurst. “It’s such a unique experience and visitors make lifetime memories, whether or not they find a diamond. Of course, finding a diamond adds to the experience!” The couple arrived at Crater of Diamonds on Thursday, September 23, a sunny-but-cool fall morning. She started to search in a shaded area near the mine entrance, but her husband suggested they venture farther out. “It was cold in the shade that morning,” Michael said, “so I told Noreen that we should go to the middle of the field, where it was warmer.” His suggestion paid off about 40 minutes later. She was walking just north of a central pathway in the search area when she spotted the sparkling gem on top of the ground. She said, “I didn’t know it was a diamond then, but it was clean and shiny, so I picked it up!” She gave the stone to her husband, who brought it to the park’s Diamond Discovery Center for identification. After examining the stone, park staff informed Michael that he was in possession of a very large yellow diamond. Park Superintendent Caleb Howell said, “When I first saw this diamond under the microscope, I thought, ‘Wow, what a beautiful shape and color!’ Mrs. Wredberg’s diamond weighs more than four carats and is about the size of a jellybean, with a pear shape and a lemonade yellow color.” Noreen was surprised and excited when park staff gave her the news a few minutes later, saying, “We really didn’t think we would find one, let alone something that big!” Park Interpreter Waymon Cox says that many of the park’s largest diamonds are found right on top of the ground. “We plow the search area periodically to loosen the soil and promote natural erosion. Diamonds are somewhat heavy for their size and lack static electricity, so dirt doesn’t stick to them. When rain uncovers a larger diamond and the sun comes out, its reflective surface is often easy to see.” Cox noted that weather conditions were perfect for Noreen to find her diamond. “Many visitors surface search for diamonds after a good rain. More than one inch of rain fell at the park between September 19 and 21. The soil had dried a little, and the sun was out when Mrs. Wredberg visited two days later. She was in just the right place to see her diamond sparkle in the morning sunlight!” Weighing 4.38 carats, Noreen’s diamond is the largest found at the park since last October, when a visitor from Fayetteville, Ark., . Finders of large Crater diamonds often choose to name their gems. Noreen named hers Lucy’s Diamond, for her husband’s kitten. “The name is sentimental to us. Lucy is mostly gray but has slight tints of yellow in her fur, similar to the light yellow of my diamond.” Noreen isn’t sure what she will do with her diamond but says she might have it cut, depending on the quality. “I don’t even know what it’s worth yet. It’s all new to me!” Park staff is not trained in diamond appraisals but offers resources to help finders decide what to do with their gems. As of this publication, 258 diamonds have been registered at Crater of Diamonds State Park in 2021, weighing more than 46 carats in total. An average of one to two diamonds are found by park visitors each day. <a href="https://www.geologyin.com/2016/08/the-only-diamond-mine-in-world-where.html" target="_blank">See:  The Only Diamond Mine In the World Where You Can Be the Miner</a> The above story is based on <a href="https://www.arkansasstateparks.com/news/visitor-finds-438-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>

Woman Finds 4.38-carat Diamond at Arkansas' Crater of Diamonds State Park

The Lucy Diamond discovered by Noreen Wredberg at Crater of Diamonds State Park in Murfreesboro, Arkansas. Photo courtesy of Arkansas State ...

100-Million-Year-Old Insect Fossil Intrigues Scientists

amber, evolution 7:56 PM

<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/-sizzIrbNh7M/YZvLSC37xDI/AAAAAAAATaM/GTUeG7myDHQqK62SvV7bQTwmJmU1dLZAACLcBGAsYHQ/s1275/100-Million-Year-Old%2BInsect%2BFossil%2BIntrigues%2BScientists%2B%25281%2529.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1274" data-original-width="1275" height="640" src="https://1.bp.blogspot.com/-sizzIrbNh7M/YZvLSC37xDI/AAAAAAAATaM/GTUeG7myDHQqK62SvV7bQTwmJmU1dLZAACLcBGAsYHQ/w640-h640/100-Million-Year-Old%2BInsect%2BFossil%2BIntrigues%2BScientists%2B%25281%2529.jpg" title="100-Million-Year-Old Insect Fossil Intrigues Scientists" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Many fossil lacewing larvae possessed extremely elongated appendages and mouthparts. | © Joachim Haug </td></tr></tbody></table>  Scientists found an unusual fossil of an insect larva of the order neuropter (which includes animals known as "lion ants", similar to dragonflies) with different characteristics to the specimens we live with today, estimating that he has lived about 100 million years ago in forests that today correspond to the region of Myanmar (or Burma). All fossils are time capsules. But unlike many other finds, insects encapsulated in amber are often perfectly preserved. "Frequently, their external morphology is as well conserved as if they had been sealed in synthetic resin," says LMU zoologist Professor Joachim T. Haug. He and his colleagues have now obtained new insights into the evolutionary history of insects from specimens that were trapped in natural tree resins 100 million years ago, in forests in what is now Myanmar. Among the finds are fossil lacewing larvae whose morphology differs strikingly from that of the 'typical' insect larva. Their most unusual features are their elongated appendages -- particularly the mouthparts called stylets, which look like hypodermic needles. "As in the case of all modern species of lacewings, these larvae were probably predators, but we know nothing about their prey," says Haug. Modern species feed on aphids, immobilizing them by injecting them with venom, and then feeding on their contents. However, the cuticle of aphids is so soft that much smaller sucking appendages would be sufficient to penetrate them. "The long stylet may have acted as a means of keeping their wounded victims at a distance until the toxin began to take effect," Haug suggests. However, since the most extreme examples of elongated appendages are found in species that are now extinct, he and his colleagues believe that this body organization may have proven to be an evolutionary dead end.<div style="width:100%;margin: 0px auto">
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</div> <h4 style="text-align: left;">The fossil larvae shed light on ecology and developmental biology</h4>Given that lacewings are now comparatively rare, the degree of species richness of the lacewing group found among the amber-encased fossils from Myanmar suggests that the group was more diverse in the Cretaceous Period. This in turn implies that these insects played a much more prominent ecological role at that time. "They were probably an important constituent of the food chain, since they effectively transformed practically inedible materials into nutritious food for birds," says Haug. The fossils also shed light on another aspect of insect evolution. Up to now, it has been assumed that the relative lengths of structures such as antennae, sensory organs and legs are subject to developmental constraints. In most insect larvae, these body parts are usually significantly shorter than they are in the mature adult and -- generally speaking -- the larva is more worm-like in form. However, in many of the lacewing larvae found in amber, antennae, mouthparts and legs tend to be markedly elongated. "This demonstrates that, from the point of view of developmental biology, there are no strictly defined limits to the lengths of such structures," Haug points out. <h4 style="text-align: left;">The nature of the habitat</h4>However, one other aspect of insect evolution continues to puzzle developmental biologists. Did the first insects that were capable of flight spend their larval lives on land or in the water? Joachim Haug and his team found a clue to the solution in 99-million-year-old amber from Myanmar -- a specimen of the fossil dragonfly species Arcanodraco filicauda. They interpret the morphology of this find as indicating that the earliest flying insects spent the initial stages of their life cycle in water. Other evidence supports this notion. Dragonflies, mayflies and stoneflies represent very old lineages of flying insects -- and their modern descendants spend the larval phase (which can last for several years) in water, before they undergo metamorphosis and take to the air as -- short-lived -- adults. "It looks as if the earliest flying insects were highly dependent on an aquatic environment for reproduction," says Haug. Perhaps the first successful take-off from the surface of a pond was accomplished with the aid of wings that acted as sails. The above story is based on <a href="https://www.lmu.de/en/newsroom/news-overview/news/intriguing-insect-fossils-preserved-in-amber.html" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px; box-sizing: border-box; color: #004276; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Materials</a><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"> provided by <a href="https://www.lmu.de/en" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px; box-sizing: border-box; color: #004276; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Ludwig-Maximilians-Universität München</a><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-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;">.

100-Million-Year-Old Insect Fossil Intrigues Scientists

Many fossil lacewing larvae possessed extremely elongated appendages and mouthparts. | © Joachim Haug Scientists found an unusual fossil o...

Trapiche Emerald: The Superstar of Trapiche Gemstones

gemstones, Mineralogy 6:52 PM

<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://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiTEq8JYiK3Y0VPyzgFi5HWjZlEDpeZJgh6rBPkvT4vA1BOUsjhzBtQZjKlipGBzTf-f69Q1BFjR_5HS2E02LfI4mVcm4UbKvuLW6aiHGRA3KKIp2XVngP7xtB23-Iz048r9KAvyOguMUhw28rDv3gueJZ7n-atqQIpXnrSRn8fTp6E_GA7RGt5xlhx/s1492/Trapiche_emerald_(cropped)%20(1).jpg" style="margin-left: auto; margin-right: auto;"><img alt="Trapiche Emerald: The Superstar of Trapiche Gemstones" border="0" data-original-height="696" data-original-width="1492" height="298" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiTEq8JYiK3Y0VPyzgFi5HWjZlEDpeZJgh6rBPkvT4vA1BOUsjhzBtQZjKlipGBzTf-f69Q1BFjR_5HS2E02LfI4mVcm4UbKvuLW6aiHGRA3KKIp2XVngP7xtB23-Iz048r9KAvyOguMUhw28rDv3gueJZ7n-atqQIpXnrSRn8fTp6E_GA7RGt5xlhx/w640-h298/Trapiche_emerald_(cropped)%20(1).jpg" title="Trapiche emerald" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Trapiche Emerald: The Superstar of Gemstones. Trapiche emerald from Muzo Mine, Colombia. Credit: Left Photo: Luciana Barbosa, Right Photo: © Martin Slama </td></tr></tbody></table> Trapiche emerald is a rare and highly valuable variety of emerald gemstone that features a unique star-like pattern (like wheel spokes). This beautiful gem variety is highly revered by the serious gem collectors and high-end jewelry designers for making expensive jewelry pieces. The radial pattern exhibits considerable variance, and often includes a hexagonal structure at the core. There is not yet consensus about the mechanism by which the pattern forms, or the conditions required for it. Various models have been proposed. Despite its starlike appearance, this unique “spoked” pattern isn’t a case of asterism (the “star stone” effect). However, trapiche emeralds may reveal chatoyancy, a “cat’s eye” effect. Parallel growth tube inclusions can create a cat’s eye in the “pie-shaped” sections as well as, rarely, along the length of whole cabbed trapiche emeralds. Expert lapidaries can orient and cut these stones to bring out this effect. <div style="margin: 0px auto; width: 100%;">
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</div> When emerald miners first discovered these patterned gems, they called them trapiche, the Spanish word for the multi-spoked cogwheels rotated by oxen tied to a yoke to grind cane sugar. They were first described in 1879 by French mineralogist Emile Bertrand at a meeting of the Société Géologique de France. Trapiche emeralds are found in the black shale host rocks of just a few Colombian mines in the western belt of the Eastern Cordillera Basin. Their appearance consists of a central core, six arms and black shale dendrites – a crystalline, branching tree-like structure that forms between the arms and around the core. They are visible when the crystals are viewed perpendicular to the c-axis and are often cut as cabochons to accentuate the six partitions.   <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/-oLcoq8mKehI/YZu7tpI3w4I/AAAAAAAATaE/li6ardyKnD04TIsvLvW3tHP-JcYgp41SACLcBGAsYHQ/s959/d7c714c6-927f-46ff-ba44-300c93c62b96.jpg" style="margin-left: auto; margin-right: auto;"><img alt="Trapiche Emerald: The Superstar of Trapiche Gemstones" border="0" data-original-height="569" data-original-width="959" height="380" src="https://1.bp.blogspot.com/-oLcoq8mKehI/YZu7tpI3w4I/AAAAAAAATaE/li6ardyKnD04TIsvLvW3tHP-JcYgp41SACLcBGAsYHQ/w640-h380/d7c714c6-927f-46ff-ba44-300c93c62b96.jpg" title="Trapiche Emerald: The Superstar of Trapiche Gemstones" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Very rare crystal Trapiche Emerald from Muso Mine, Colombia. Photo: Cricksgemstone</td></tr></tbody></table> During the formation of an emerald crystal, black carbon impurities may enter the gemstone mix. Because of emerald’s hexagonal crystal structure, these impurities may fill in at the crystal junctions, forming a six-point radial pattern. In some trapiche emeralds, inclusions of albite, quartz, carbonaceous materials, or lutite may outline the hexagonal emerald core. From there, they extend in spokes that divide the surrounding emerald material into six trapezoidal sectors. The extraordinarily rare trapiche emeralds are primarily found in the Muzo, Coscuez and Peñas Blancas mines of Colombia. The trapiche pattern is not an asterism, which is a six-rayed star pattern sometimes seen in cabochon-cut rubies, sapphires and other gemstones. <a href="https://www.geologyin.com/2017/12/how-does-trapiche-emerald-form.html" target="_blank">See also: How Does a Trapiche Emerald Form?</a>

Trapiche Emerald: The Superstar of Trapiche Gemstones

Trapiche Emerald: The Superstar of Gemstones. Trapiche emerald from Muzo Mine, Colombia. Credit: Left Photo: Luciana Barbosa, Right Photo: ©...

Scientists Figure Out What Happens to Earth's Disappearing Crust

Earth History, Tectonic 7:55 PM

<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/-cXIaii43sR4/YZp5nk9pMVI/AAAAAAAATZ8/EBj_13R9bKk2a-qxDjiUswipmmMftC_1QCLcBGAsYHQ/s1280/fate-of-sinking-tecton%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="835" data-original-width="1280" height="418" src="https://1.bp.blogspot.com/-cXIaii43sR4/YZp5nk9pMVI/AAAAAAAATZ8/EBj_13R9bKk2a-qxDjiUswipmmMftC_1QCLcBGAsYHQ/w640-h418/fate-of-sinking-tecton%2B%25281%2529.jpg" title="Modern plate tectonics may have only got going in the past billion years." width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Researchers including The University of Texas at Austin have published a study in Nature that says subducting tectonic plates become segmented like a slinky snake, in a process similar to geologic boudinage (pictured) but on a much larger scale. Credit: Haakon Fossen, Structural Geology/Cambridge University Press </td></tr></tbody></table>  Like a giant broken-up cookie whose pieces float atop a sea of scalding milk, Earth's outer shell is made of (less-tasty) rocky rafts that constantly bump into and dive beneath each other in a process called plate tectonics. Our world's surface is a jumble of jostling tectonic plates, with new ones emerging as others are pulled under. The ongoing cycle keeps our continents in motion and drives life on Earth. But what happens when a plate disappears into the planet's interior? The question has long puzzled scientists because conventional wisdom said that sinking tectonic plates must remain intact to keep pulling on the portion behind it, but according to geophysical evidence, they are destroyed. Now, in a study published in Nature, scientists say they've found an answer that reconciles the two stories: Plates are significantly weakened as they sink but not so much that they break apart entirely. The finding came after scientists put tectonic plates through a computer-generated gauntlet of destructive geologic forces. The model showed that as the plate enters the mantle, it bends abruptly downward, cracking its cold, brittle back. At the same time, the bending changes the fine grain structure of the rock along its underbelly, leaving it weakened. Combined, the stresses pinch the plate along its weak points, leaving it mostly intact but segmented like a slinky snake. <div style="width:100%;margin: 0px auto">
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</div> This means the plate continues to be pulled under despite becoming folded and distorted. According to the researchers, the model predicted a scenario that matches observations from Japan. Studies of the region where the Pacific tectonic plate dives -- or subducts -- under Japan have turned up large cracks where the plate bends downward, and they have shown signs of weaker material underneath. Deep seismic imaging conducted by The University of Texas at Austin's Steve Grand has also revealed tectonic shapes in the Earth's mantle under Japan that appear a close match for the slinky snake in the model. Co-author Thorsten Becker, a professor in UT's Jackson School of Geosciences, said that the study does not necessarily close the book on what happens to subducting plates, but it certainly gives a compelling case to explain several important geologic processes. "It's an example of the power of computational geosciences," said Becker who assisted in developing the model and is a faculty associate at UT's Oden Institute for Computational Engineering & Sciences. "We combined these two processes that geology and rock mechanics are telling us are happening, and we learned something about the general physics of how the Earth works that we wouldn't have expected. As a physicist, I find that exciting." The study's lead author, Taras Gerya, a professor of geophysics at ETH Zurich, added that until now, geophysicists had lacked a comprehensive explanation for how tectonic plates bend without breaking. Things got interesting when the researchers ran their simulations with a hotter interior, similar to the early Earth. In these simulations, the tectonic snake segments made it only a few miles into the mantle before breaking off. That means that subduction would have occurred intermittently, raising the possibility that modern plate tectonics began only within the past billion years. "Personally, I think there are a lot of good arguments for plate tectonics being much older," Becker said, "but the mechanism revealed by our model suggests things might be more sensitive to the temperature of the mantle than we thought, and that, I think, could lead to interesting new avenues of discussion." Becker and Gerya were joined by David Bercovici, a geophysicist at Yale University whose investigation into how rock grains are altered in the deep mantle helped motivate the research. The study is based on a two-dimensional computer model of plate tectonics incorporating Bercovici's rock deformation research and other plate-weakening mechanics. The researchers are now studying the phenomena using 3D models and plan to investigate what those models can tell them about the occurrence of earthquakes. The above story is based on  <a href="https://news.utexas.edu/2021/11/11/fate-of-sinking-tectonic-plates-is-revealed/" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px !important; box-sizing: border-box; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Materials</a><span style="-webkit-text-stroke-width: 0px; background-color: white; display: inline !important; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"> provided by <a href="https://www.utexas.edu/" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px !important; box-sizing: border-box; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">University of Texas at Austin</a><span style="-webkit-text-stroke-width: 0px; background-color: white; display: inline !important; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;">.

Scientists Figure Out What Happens to Earth's Disappearing Crust

Researchers including The University of Texas at Austin have published a study in Nature that says subducting tectonic plates become segment...

Uncovering the Surprising Secrets Behind Earth’s First Major Mass Extinction

Earth History, Fossils 8:27 PM

<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/-PR4jFcHwVdE/YZPojoumIWI/AAAAAAAATZs/4rX0IeynjEYCOWbItLxPVMTuhYTB0OvSQCLcBGAsYHQ/s1238/1238px-LibertyFormationSlab092313%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1024" data-original-width="1238" height="530" src="https://1.bp.blogspot.com/-PR4jFcHwVdE/YZPojoumIWI/AAAAAAAATZs/4rX0IeynjEYCOWbItLxPVMTuhYTB0OvSQCLcBGAsYHQ/w640-h530/1238px-LibertyFormationSlab092313%2B%25281%2529.jpg" title="Fossiliferous limestone slab from the Liberty Formation (Upper Ordovician) of Caesar Creek State Park near Waynesville, Ohio. Photo: Willy Nelson." width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"> Fossiliferous limestone slab from the Liberty Formation (Upper Ordovician) of Caesar Creek State Park near Waynesville, Ohio. Photo: Willy Nelson.</td></tr></tbody></table>  Around 85% of marine species, most of which lived in shallow oceans near continents, disappeared during that time.We all know that the dinosaurs died in a mass extinction. But did you know that there were other mass extinctions? There are five most significant mass extinctions, known as the “big five,” where at least three-quarters of all species in existence across the entire Earth faced extinction during a particular geological period of time. With current trends of global warming and climate change, many researchers now believe we may be in a sixth. Discovering the root cause of Earth’s mass extinctions has long been a hot topic for scientists, as understanding the environmental conditions that led to the elimination of the majority of species in the past could potentially help prevent a similar event from occurring in the future. A team of scientists from Syracuse University’s Department of Earth and Environmental Sciences, the University of California, Berkeley and the University of California, Riverside, Université Bourgogne Franche-Comté, the University of New Mexico, the University of Ottawa, the University of Science and Technology of China and Stanford University recently co-authored a paper exploring the Late Ordovician mass extinction (LOME), which is the first, or oldest of the “big five (~445 million years ago).” Around 85% of marine species, most of which lived in shallow oceans near continents, disappeared during that time. <div style="width:100%;margin: 0px auto">
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</div> Lead author Alexandre Pohl, from UC Riverside (now a postdoctoral research fellow at Université Bourgogne Franche-Comté in Dijon, France) and his co-authors investigated the ocean environment before, during, and after the extinction in order to determine how the event was brewed and triggered. The results from their study will be published in the journal Nature Geoscience on Nov. 1. To paint a picture of the oceanic ecosystem during the Ordovician Period, mass extinction expert Seth Finnegan, associate professor at UC Berkeley, says that seas were full of biodiversity. Oceans contained some of the first reefs made by animals, but lacked an abundance of vertebrates. “If you had gone snorkeling in an Ordovician sea you would have seen some familiar groups like clams and snails and sponges, but also many other groups that are now very reduced in diversity or entirely extinct like trilobites, brachiopods and crinoids” says Finnegan. Unlike with rapid mass extinctions, like the Cretaceous-Tertiary extinction event where dinosaurs and other species died off suddenly some 65.5 million years ago, Finnegan says LOME played out over a substantial period of time, with estimates between less than half a million to almost two million years. One of the major debates surrounding LOME is whether lack of oxygen in seawater caused that period’s mass extinction. To investigate this question, the team integrated geochemical testing with numerical simulations and computer modeling. Zunli Lu, professor of Earth and environmental sciences at Syracuse University, and his students took measurements of iodine concentration in carbonate rocks from that period, contributing important findings about oxygen levels at various ocean depths. The concentration of the element iodine in carbonate rocks serves as an indicator for changes in oceanic oxygen level in Earth's history. Their data, combined with computer modeling simulations, suggested that there was no evidence of anoxia – or lack of oxygen – strengthening during the extinction event in the shallow ocean animal habitat where most organisms lived, meaning that climate cooling that occurred during the Late Ordovician period combined with additional factors likely was responsible for LOME. On the other hand, there is evidence that anoxia in deep oceans expanded during that same time, a mystery that cannot be explained by the classic model of ocean oxygen, climate modeling expert Alexandre Pohl says. “Upper-ocean oxygenation in response to cooling was anticipated, because atmospheric oxygen preferentially dissolves in cold waters,” Pohl says. “However, we were surprised to see expanded anoxia in the lower ocean since anoxia in Earth’s history is generally associated with volcanism-induced global warming.” They attribute the deep-sea anoxia to the circulation of seawater through global oceans. Pohl says that a key point to keep in mind is that ocean circulation is a very important component of the climatic system. He was part of a team led by senior modeler Andy Ridgwell, professor at UC Riverside, whose computer modeling results show that climate cooling likely altered ocean circulation pattern, halting the flow of oxygen-rich water in shallow seas to the deeper ocean. According to Lu, recognizing that climate cooling can also lead to lower oxygen levels in some parts of the ocean is a key takeaway from their study. “For decades, the prevailing school of thoughts in our field is that global warming causes the oceans to lose oxygen and thus impact marine habitability, potentially destabilizing the entire ecosystem,” Lu says. “In recent years, mounting evidence point to several episodes in Earth’s history when oxygen levels also dropped in cooling climates.” While the causes of Late Ordovician extinction have not been fully agreed upon, nor will they for some time, the team’s study rules out changes in oxygenation as a single explanation for this extinction and adds new data favoring temperature change being the killing mechanism for LOME. Pohl is hopeful that as better climate data and more sophisticated numerical models become available, they will be able to offer a more robust representation of the factors that may have led to the Late Ordovician mass extinction.  The above story is based on <a href="https://thecollege.syr.edu/news-all/news-from-2021/uncovering-the-secrets-behind-earths-first-major-mass-extinction/" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px !important; box-sizing: border-box; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Materials</a><span style="-webkit-text-stroke-width: 0px; background-color: white; display: inline !important; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"> provided by <a href="https://www.syracuse.edu/" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px !important; box-sizing: border-box; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Syracuse University</a><span style="-webkit-text-stroke-width: 0px; background-color: white; display: inline !important; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;">. Original written by Dan Bernardi.

Uncovering the Surprising Secrets Behind Earth’s First Major Mass Extinction

Fossiliferous limestone slab from the Liberty Formation (Upper Ordovician) of Caesar Creek State Park near Waynesville, Ohio. Photo: Willy ...

Diamond Hauled From Deep Inside Earth Holds Never-Before-Seen Mineral

Diamonds, Geochemistry 7:32 PM

<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/--CdIwDw2WjM/YZE2oa55PNI/AAAAAAAATZU/_FN99K6wcO4576kWDJweeSK-TZLyZQntgCLcBGAsYHQ/s1206/111021_cg_mineral-davemaoite_feat-1030x580%2B%25281%2529.jpg" style="margin-left: auto; margin-right: auto;"><img alt="Diamond Hauled From Deep Inside Earth Holds Never-Before-Seen Mineral" border="0" data-original-height="580" data-original-width="1206" height="308" src="https://1.bp.blogspot.com/--CdIwDw2WjM/YZE2oa55PNI/AAAAAAAATZU/_FN99K6wcO4576kWDJweeSK-TZLyZQntgCLcBGAsYHQ/w640-h308/111021_cg_mineral-davemaoite_feat-1030x580%2B%25281%2529.jpg" title="The newfound mineral, dubbed davemaoite, only exists deep in Earth’s mantle" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Diamond Hauled From Deep Inside Earth Holds Never-Before-Seen Mineral. The Tiny Gray Blobs of Mineral Embedded in This Slice of Clear Diamond Are the First Samples of Newly Named Davemaoite, a Calcium Silicate Perovskite Mineral That Only Forms in the Lower Mantle. Aaron Celestian/Natural History Museum of Los Angeles County</td></tr></tbody></table>  This mineral shouldn't exist on Earth's surface. But researchers found it inside a diamond. When it comes to knowing what actually lies deep inside the Earth, diamonds are a geologist’s best friend. A team of researchers affiliated with a host of institutions in the U.S. has found a sample of a mineral previously believed to be unable to exist in nature. In their paper published in the journal Science, the group describes their study of a diamond found in Orapa, Botswana and the mineral specks they found trapped inside. Yingwei Fei with the Carnegie Institution for Science has published a Perspectives piece in the same journal issue outlining the work by the team and explaining why the mineral find is important to geology. In 1975, a team of researchers created what Fei describes as a "high-pressure phase of aSiO3 "—a mineral that had been theorized to exist, but only under certain conditions. To synthesize the mineral, the researchers had to place its building materials under high heat and pressure conditions. They noted that as soon as the pressure was relieved, the mineral immediately changed to a form of glass. This finding suggested that it was not likely that the mineral could exist in nature. That assumption has now been proven wrong, as the diamond found in Botswana contained three tiny samples of it. <div style="margin: 0px auto; width: 100%;">
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</div> Because the mineral, now called calcium silicate perovskite, can only form under extreme heat and pressure conditions, the researchers suspect the specks they found in the diamond had to form deep below the Earth's surface—perhaps as far down as 660 to 900 km. They note that calcium silicate is found in multiple forms, one of which is wollastonite—a mineral found in the Earth's crust. They note also that material in the crust and mantle moves between the two because rocks are pushed around by plate tectonics. Prior research has shown that as they move, minerals in the rocks often undergo transformations, but some become trapped in diamond. Diamond is a sort of base material; once conditions arise for its formation, the resulting diamond remains intact regardless of what goes on around it. The researchers suspect a form of calcium silicate (such as wollastonite) found itself in just the right conditions to form calcium silicate perovskite far below the surface and shortly thereafter found itself surrounded by carbon that was in the process of being pressed into a diamond. After that, the material surrounding the diamond carried it upward until it reached the surface, where it was found. The researchers have named it "davemaoite," after noted geologist Ho-Kwang "Dave" Mao. Diamonds act like time capsules, locking in the original mineral forms on their journey to the surface. The discovery of davemaoite is not only a confirmation of its existence, but it also reveals the location of some sources of heat deep inside Earth. Although it’s a calcium silicate mineral, davemaoite is also host to a rogue’s gallery of different elements that sneak into its crystal structure. That includes radioactive elements such as uranium, thorium and potassium, as well as rare-earth elements. Such radioactive elements have long been thought to produce about a third of the heat circulating in the lower mantle (the other two-thirds is left over from the planet’s original formation 4.55 billion years ago). By identifying the chemical makeup of davemaoite, researchers can now confirm where those elements reside. That’s because the Botswana diamond also contained a high-pressure form of ice as well as another high-pressure mineral known as wüstite. The presence of those inclusions helped narrow down the rough pressures at which the davemaoite might have formed: somewhere between 24 billion pascals and 35 billion pascals, Tschauner says. It’s hard to say exactly what depth that corresponds to, he adds. But the discovery directly links heat generation (the radioactive materials), the water cycle (the ice) and the carbon cycle (represented by the formation of the diamond itself), all in the deep mantle, Tschauner says. Another intriguing aspect of this new mineral is that it’s surprisingly rich in potassium compared with laboratory predictions, says Sang-Heon Shim, a geophysicist at Arizona State University in Tempe. Most experimental efforts to create the mineral came up with “nearly pure calcium silicate perovskite,” Shim says. Scientists can only speculate right now what the source was for the extra potassium, but this unexpected composition hints that the lower mantle may be a more motley mix than thought, with complexity difficult to predict from lab studies alone. The study was published in the journal <a href="https://www.sciencenews.org/article/flaws-make-it-geologists-best-friend" rel="nofollow" target="_blank">Science X Network.</a>

Diamond Hauled From Deep Inside Earth Holds Never-Before-Seen Mineral

Diamond Hauled From Deep Inside Earth Holds Never-Before-Seen Mineral. The Tiny Gray Blobs of Mineral Embedded in This Slice of Clear Diamon...

Baby Bird Fossil Is 'Rarest of the Rare'

evolution, Fossils 9:26 PM

<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/-gMXwT1y6oys/YYwN0kFUtYI/AAAAAAAATZI/9mEhFAzh_VAPTthwITzdiY-mKuH_at_-ACLcBGAsYHQ/s976/Baby%2BBird%2BFossil%2BIs%2B%2527Rarest%2Bof%2Bthe%2BRare%2527%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="976" data-original-width="976" height="640" src="https://1.bp.blogspot.com/-gMXwT1y6oys/YYwN0kFUtYI/AAAAAAAATZI/9mEhFAzh_VAPTthwITzdiY-mKuH_at_-ACLcBGAsYHQ/w640-h640/Baby%2BBird%2BFossil%2BIs%2B%2527Rarest%2Bof%2Bthe%2BRare%2527%2B%25281%2529.jpg" title="The fossil seen under synchrotron radiation" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">The fossil seen under synchrotron radiation. Photo: Fabien Knoll </td></tr></tbody></table> The chick lived 127 million years ago and belonged to a group of primitive birds that shared the planet with the dinosaurs. Fossils of birds from this time period are rare, with baby fossils seen as "the rarest of the rare". The tiny fossil of a prehistoric baby bird is helping scientists understand how early avians came into the world in the Age of Dinosaurs. The fossil, which dates back to the Mesozoic Era (250-65 million years ago), is a chick from a group of prehistoric birds called, Enantiornithes. Made up of a nearly complete skeleton, the specimen is amongst the smallest known Mesozoic avian fossils ever discovered. It measures less than five centimetres -- smaller than the little finger on an average human hand -- and would have weighed just three ounces when it was alive. What makes this fossil so important and unique is the fact it died not long after its birth. This is a critical stage in a bird's skeletal formation. That means this bird's extremely short life has given researchers a rare chance to analyse the species' bone structure and development. Studying and analysing ossification -- the process of bone development -- can explain a lot about a young bird's life the researchers say. It can help them understand everything from whether it could fly or if it needed to stay with its parents after hatching or could survive on its own. The lead author of the study, Fabien Knoll, from The University of Manchester's Interdisciplinary Centre for Ancient Life (ICAL), School of Earth and Environmental Sciences, and the ARAID -- Dinopolis in Spain explains: 'The evolutionary diversification of birds has resulted in a wide range of hatchling developmental strategies and important differences in their growth rates. By analysing bone development we can look at a whole host of evolutionary traits.' With the fossil being so small the team used synchrotron radiation to picture the tiny specimen at a 'submicron' level, observing the bones' microstructures in extreme detail. Knoll said: 'New technologies are offering palaeontologists unprecedented capacities to investigate provocative fossils. Here we made the most of state-of-the-art facilities worldwide including three different synchrotrons in France, the UK and the United States.' The researchers found the baby bird's sternum (breastplate bone) was still largely made of cartilage and had not yet developed into hard, solid bone when it died, meaning it wouldn't have been able to fly. The patterns of ossification observed in this and the other few very young enantiornithine birds known to date also suggest that the developmental strategies of this particular group of ancient avians may have been more diverse than previously thought. However, the team say that its lack of bone development doesn't necessarily mean the hatchling was over reliant on its parents for care and feeding, a trait known as being 'altricial'. Modern day species like love birds are highly dependent on their parents when born. Others, like chickens, are highly independent, which is known as 'precocial'. Although, this is not a black-and-white issue, but rather a spectrum, hence the difficulty in clarifying the developmental strategies of long gone bird species. Luis Chiappe, from the LA Museum of Natural History and study's co-author added: 'This new discovery, together with others from around the world, allows us to peek into the world of ancient birds that lived during the age of dinosaurs. It is amazing to realise how many of the features we see among living birds had already been developed more than 100 million years ago.'   The above story is based on <a href="http://www.manchester.ac.uk/discover/news/127-million-year-old-baby-bird-fossil-sheds-light-on-avian-evolution/" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px !important; box-sizing: border-box; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Materials</a><span style="-webkit-text-stroke-width: 0px; background-color: white; display: inline !important; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"> provided by <a href="http://www.manchester.ac.uk/" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px !important; box-sizing: border-box; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">University of Manchester</a><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline !important; float: none; font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; 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-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px;">.

Baby Bird Fossil Is 'Rarest of the Rare'

The fossil seen under synchrotron radiation. Photo: Fabien Knoll The chick lived 127 million years ago and belonged to a group of primitive ...

Astonishing Fluorite Ball

Minerals 9:52 PM

<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://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitX2ZWD42jPblAsK-H7rFXanDIeyOvRX--t-HoMgb6ZJMaela-F4fuIaiFjbtZHkxiLepwZbQiWbEGskbRi1ClYvblEQFWsz5Hb4u_Q-ScnXktGP9aHpS2WT2c79inMqezDPBL7rCv5NuIpTEu_xrgqm5KkCmYVx0L-JIPNZEYT_9zQWmFdDHpwYP_/s1024/Fluorite%20Ball.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="840" data-original-width="1024" height="526" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitX2ZWD42jPblAsK-H7rFXanDIeyOvRX--t-HoMgb6ZJMaela-F4fuIaiFjbtZHkxiLepwZbQiWbEGskbRi1ClYvblEQFWsz5Hb4u_Q-ScnXktGP9aHpS2WT2c79inMqezDPBL7rCv5NuIpTEu_xrgqm5KkCmYVx0L-JIPNZEYT_9zQWmFdDHpwYP_/w640-h526/Fluorite%20Ball.jpg" title="Fluorite Ball" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Collection & photo: Roger Lang</td></tr></tbody></table> Very nice translucent fluorite ball on a yellowish calcite crystal in a quartz geode in trapp basalt. The diameter of the large fluorite ball. From: Mahodari, Sinnar, Nashik District, Maharashtra, India Color: Green, Blue, White, Yellow, Red, Black, Purple, Pink, Orange, Brown Luster: Vitreous Crystal system: Cubic crystal system Chemical formula: CaF₂ Hardness (Mohs hardness scale): 4

Astonishing Fluorite Ball

Collection & photo: Roger Lang Very nice translucent fluorite ball on a yellowish calcite crystal in a quartz geode in trapp basalt. T...

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