April 2022

Earliest Evidence Of Plate Tectonics Found In 3.8-Billion-Year-Old Crystals

Earth History, Geology, Tectonic 11:20 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://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjHGhDYSMtvWCpwn04genuQK9TKVUjdcnrIA5ysif-nYc32ehI3Wkb39nP0m1xchX1oyhvhS1xJREQOsdp4F0wVQAfSZP7O659m42sjeh8Xyv2Uf5Xsak-QGZ9vZn-phrwGyOtTofmMmUPfsFlnNn2usPxrRa9KaCpog3rp2Spe7t4MtKOR5DNvPgfo/s1200/Cross-section%20of%20Earth's%20crust%20to%20explain%20subduction%20and%20plate%20tectonics%20(1.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="720" data-original-width="1200" height="384" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjHGhDYSMtvWCpwn04genuQK9TKVUjdcnrIA5ysif-nYc32ehI3Wkb39nP0m1xchX1oyhvhS1xJREQOsdp4F0wVQAfSZP7O659m42sjeh8Xyv2Uf5Xsak-QGZ9vZn-phrwGyOtTofmMmUPfsFlnNn2usPxrRa9KaCpog3rp2Spe7t4MtKOR5DNvPgfo/w640-h384/Cross-section%20of%20Earth's%20crust%20to%20explain%20subduction%20and%20plate%20tectonics%20(1.jpg" title="Earliest Evidence Of Plate Tectonics Found In 3.8-Billion-Year-Old Crystals" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Cross-section of Earth's crust to explain subduction and plate tectonics. GETTY<br /></td></tr></tbody></table> <br /></p><p>A handful of ancient zircon crystals found in South Africa hold the oldest evidence of subduction, a key element of plate tectonics, according to a new study published in the open access journal AGU Advances.<br /></p><p style="text-align: left;">A handful of ancient zircon crystals found in South Africa hold the oldest evidence of subduction, a key element of plate tectonics, according to a new study published today in AGU Advances, AGU’s journal for high-impact, open-access research and commentary across the Earth and space sciences.<br /><br />These rare time capsules from Earth’s youth point to a transition around 3.8 billion years ago from a long-lived, stable rock surface to the active processes that shape our planet today, providing a new clue in a hot debate about when plate tectonics was set in motion.<br /><br />Earth’s crust and the top layer of mantle just under it are broken up into rigid plates that move slowly on top of viscous but mobile lower layers of mantle rock. Heat from Earth’s core drives this slow but inexorable motion, responsible for volcanoes, earthquakes, and the uplift of mountain ranges.<br /><br />Estimates for when this process revved up and modern crust formed range from over 4 billion years ago to just 800 million years ago. Uncertainty arises because the geologic record from Earth’s youth is sparse, due to the surface recycling effect of plate tectonics itself. Almost nothing remains from the Hadean Eon, Earth’s first 500 million years.<br /><div style="width:100%;margin: 0px auto">
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</div><br />“The Hadean Earth is this big mystery box,” said Nadja Drabon, a geologist at Harvard University and the lead author of the new study.<br /></p><h4 style="text-align: left;"><span style="font-family: georgia;">TINY TIME CAPSULES</span></h4><p style="text-align: left;">In an exciting step forward in solving this mystery, in 2018 Drabon and her colleagues unearthed a chronological series of 33 microscopic zircon crystals from a rare, ancient block of crust in the Barberton Greenstone Belt in South Africa, that formed at different times over a critical 800-million-year span from 4.15 to 3.3 billion years ago.<br /><br />Zircon is a relatively common accessory mineral in Earth’s crust, but ancient representatives from the Hadean Eon, 4 to 4.56 billion years ago, are exceedingly rare, found in only 12 places on Earth, and usually in numbers fewer than three at each location.<br /><br />Hafnium isotopes and trace elements preserved in the Greenstone Belt zircons told a story about the conditions on Earth at the time they crystalized. Zircons 3.8-billion-years-old and younger appeared to have formed in rock experiencing pressures and melting similar to modern subduction zones, suggesting the crust may have started moving.<br /><br />“When I say plate tectonics, I’m specifically referring to an arc setting, when one plate goes under another and you have all that volcanism — think of the Andes, for example, and the Ring of Fire,” Drabon said, describing a classic example of subduction.<br /><br />“At 3.8 billion years there is a dramatic shift where the crust is destabilized, we have new rocks forming and we see geochemical signatures becoming more and more similar to what we see in modern plate tectonics,” Drabon said.<br /><br />In contrast, the older zircons preserved evidence of a global cap of “protocrust” derived from remelting mantle rock that had remained stable for 600 million years, the study found.<br /></p><h4 style="text-align: left;"><span style="font-family: georgia;">SIGNS OF GLOBAL CHANGE</span></h4><p style="text-align: left;">The new study found a similar transition to conditions resembling modern subduction in zircons from other locations around the world, dating to within about 200 million years of the South African zircons.<br /><br />“We see evidence for a significant change on the Earth around 3.8 to 3.6 billion years ago and evolution toward plate tectonics is one clear possibility.” Drabon said.<br /><br />While not conclusive, the results suggest a global change may have begun, Drabon said, possibly starting and stopping in scattered locations before settling into the efficient global engine of constantly moving plates we see today.<br /><br />Plate tectonics shapes Earth’s atmosphere as well as its surface. Release of volcanic gasses and production of new silicate rock, which consumes large amounts carbon dioxide from the atmosphere, temper large temperature swings from too much or too little greenhouse gas.<br /><br />“Without all of the recycling and new crust forming, we might be going back and forth between boiling hot and freezing cold,” Drabon said. “It’s kind of like a thermostat for the climate.”<br /><br />Plate tectonics has, so far, only been observed on Earth, and may be essential to making a planet livable, Drabon said, which makes the origins of plate motions of interest in research into the early development of life.<br /><br />“The record we have for the earliest Earth is really limited, but just seeing a similar transition in so many different places makes it really feasible that it might have been a global change in crustal processes,” Drabon said. “Some kind of kind of reorganization was happening on Earth.” </p><p style="text-align: left;"><br /></p><p style="text-align: left;"><br /><i><u>The above story is based on <a href="https://news.agu.org/press-release/earliest-geochemical-evidence-of-plate-tectonics-found-in-3-8-billion-year-old-crystal/" rel="nofollow" target="_blank">materials </a>provided by  <a href="https://sites.agu.org/" rel="nofollow" target="_blank">American Geophysical Union</a>.</u></i><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #888888; display: inline !important; float: none; font-family: Arial, "Helvetica Neue", Helvetica, Helvetica, sans-serif; font-size: 11.52px; 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;"><span><br /></span></span></p>

Earliest Evidence Of Plate Tectonics Found In 3.8-Billion-Year-Old Crystals

Cross-section of Earth's crust to explain subduction and plate tectonics. GETTY A handful of ancient zircon crystals found in South Af...

Ancient Spider Reveals a Secret Glow That Sustained It For Eternity

extinction, Fossils 10:08 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://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgrvQINI5AhM_8XEdOqTZ-84pD0Sxc90HFyDzhxzeygVd8FVOxsUov_1-sIK8Z870gos81ONVpVUrLV2iBpMKXkcD5ayWxR-cRG3LTIS2q9Yr4_DnOHIO42jwnx46Rxc_npz6qyA7J6Gijvh4vA3sRd1v2nOvBQdY_fCZWUh7iqDiF-9pPpDNMPJGL1/s1584/Ancient%20Spider%20Reveals%20a%20Secret%20Glow%20That%20Sustained%20It%20For%20Eternity.jpg" style="margin-left: auto; margin-right: auto;"><img alt="Ancient Spider Reveals a Secret Glow That Sustained It For Eternity" border="0" data-original-height="1379" data-original-width="1584" height="558" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgrvQINI5AhM_8XEdOqTZ-84pD0Sxc90HFyDzhxzeygVd8FVOxsUov_1-sIK8Z870gos81ONVpVUrLV2iBpMKXkcD5ayWxR-cRG3LTIS2q9Yr4_DnOHIO42jwnx46Rxc_npz6qyA7J6Gijvh4vA3sRd1v2nOvBQdY_fCZWUh7iqDiF-9pPpDNMPJGL1/w640-h558/Ancient%20Spider%20Reveals%20a%20Secret%20Glow%20That%20Sustained%20It%20For%20Eternity.jpg" title="Fossilized spider from the Aix-en-Provence Formation in France seen in hand sample overlain with fluorescent microscopy image of the same fossil. Under normal lighting the spider fossil is hard to differentiate from the surrounding rock matrix, but when the fossil is excited by UV-illumination its chemical composition causes it to autofluoresce brightly, revealing additional details of its preservation. Credit: Olcott et al" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: times;">Ancient Spider Reveals a Secret Glow That Sustained It For Eternity. Fossilized spider from the Aix-en-Provence Formation in France seen in hand sample overlain with fluorescent microscopy image of the same fossil. Under normal lighting the spider fossil is hard to differentiate from the surrounding rock matrix, but when the fossil is excited by UV-illumination its chemical composition causes it to autofluoresce brightly, revealing additional details of its preservation. Credit: Olcott et al</span><br /></td></tr></tbody></table><br /><p></p><p>A fossilized spider that glows under ultraviolet light has given away the secret of its exceptional 23-million-year-long existence.<br /></p><p>A geologic formation near Aix-en-Provence, France, is famed as one of the world’s chief treasure troves of fossil species from the Cenozoic Era. Since the late 1700s, scientists there have been unearthing amazingly well-preserved fossilized plants and animals.<br /><br />The Aix-en-Provence formation is particularly known for its fossilized terrestrial arthropods from the Oligocene Period (between roughly 23-34 million years ago). Because arthropods — animals with exoskeletons like spiders — are rarely fossilized, their abundance at Aix-en-Provence is remarkable.<br /><br />A new study in the journal Communications Earth & Environment from researchers at the University of Kansas is the first to ask: What are the unique chemical and geological processes at Aix-en-Provence that preserve spiders from the Oligocene Period so exquisitely?<br /><br />“Most life doesn’t become a fossil,” said lead author Alison Olcott, associate professor of geology and director of the Center for Undergraduate Research at KU. “It's hard to become a fossil. You have to die under very specific circumstances, and one of the easiest ways to become a fossil is to have hard parts like bones, horns and teeth. So, our record of soft-body life and terrestrial life, like spiders, is spotty — but we have these periods of exceptional preservation when all circumstances were harmonious for preservation to happen.”<br /></p><div style="margin: 0px auto; width: 100%;">
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</div><br />Olcott and her KU co-authors Matthew Downen — then a doctoral candidate in the Department of Geology and now the assistant director at Center for Undergraduate Research — and Paul Selden, KU distinguished professor emeritus, along with James Schiffbauer of the University of Missouri, sought to discover the exact processes at Aix-en-Provence that provided a pathway for preservation for the spider fossils.<br /><br />“Matt was working on describing these fossils, and we decided — more or less on a whim — to stick them under the fluorescent microscope to see what happened,” Olcott said. “To our surprise they glowed, and so we got very interested in what the chemistry of these fossils was that made them glow. If you just look at the fossil on the rock, they're almost indistinguishable from the rock itself, but they glowed a different color under the fluorescent scope. So, we started exploring the chemistry and discovered the fossils themselves contain a black polymer made of carbon and sulfur that, under the microscope, looks like the tar you see on the road. We also noticed there were just thousands and thousands and thousands of microalgae all around the fossils and coating the fossils themselves.”<br /><br />Olcott and her colleagues hypothesize that the extracellular substance these microalgae, called diatoms, are known to produce would have protected the spiders from oxygen and promoted sulfurization of the spiders, a chemical change that would explain preservation of the fossils as carbonaceous films over the millions of ensuing years.<br /><br />“These microalgae make the sticky, viscous gloop — that's how they stick together,” the KU researcher said. “I hypothesized the chemistry of those microalgae, and the stuff they were extruding, actually made it possible for this chemical reaction to preserve the spiders. Basically, the chemistry of the microalgae and the chemistry of the spiders work together to have this unique preservation happen.”<br /><br />Indeed, this sulfurization phenomenon is the same as a common industrial treatment used to preserve rubber.<br /><br />“Vulcanization is a naturally occurring process — we do it ourselves to cure rubber in a well-known process,” Olcott said. “Sulfurization takes carbon and cross-links it with sulfur and stabilizes the carbon, which is why we do it to rubber to make it last longer. What I think happened here chemically is the spider exoskeleton is chitin, which is composed of long polymers with carbon units near each other, and it's a perfect environment to have the sulfur bridges come in and really stabilize things.”<br /><br />Olcott said the presence of diatomic mats may potentially act as a guide to find more deposits of well-preserved fossils in the future.<br /><br />“The next step is expanding these techniques to other deposits to see if preservation is tied to diatom mats,” she said. “Of all the other exceptional fossil preservation sites in the world in the Cenozoic Era, something like 80 percent of them are found in association with these microalgae. So, we’re wondering if this explains most of these fossil sites that we have in this time — basically from soon after the dinosaurs went extinct until now. This mechanism could be responsible for giving us information to explore the evolution of insects and other terrestrial life post-dinosaurs and to understand climate change, because there's a period of rapid climate change and these terrestrial organisms help us understand what happened to life last time climate started shifting.”<br /><p></p><p><br /></p><p><i><u>The above story is based on <a href="https://news.ku.edu/2022/04/21/glowing-spider-fossils-prompt-breakthrough-study-how-they-were-preserved-aix-en-provence" rel="nofollow" target="_blank">materials </a>provided by The<a href="https://ku.edu/" rel="nofollow" target="_blank"> University of Kansas.</a></u></i><br /></p>

Ancient Spider Reveals a Secret Glow That Sustained It For Eternity

Ancient Spider Reveals a Secret Glow That Sustained It For Eternity. Fossilized spider from the Aix-en-Provence Formation in France seen in ...

Scientists Confirm Discovery of ‘Hottest Rock on Earth’

Earth History, Earth News, Geochemistry 11:25 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://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi70ggMDLAxt1XYTBugVSKE0LC4ZH512gg1vE_lRQCMV-f4DkhcDVoj1Di5I_xIIcc0VBCMo_ZFD0_S85gN34gkYd7e4mThhcWVbk53EkkCXGBbMyonj_D23KFW4-yQOPFNGsSsTXI-I0joowPc4HYqO60DPsN4bsuwaidwBrN3XKOXkCPaDWwH7Sx5/s1920/Scientists%20Confirm%20Discovery%20of%20%E2%80%98Hottest%20Rock%20on%20Earth%E2%80%99%20(1).jpg" style="margin-left: auto; margin-right: auto;"><img alt="Scientists Confirm Discovery of ‘Hottest Rock on Earth’" border="0" data-original-height="1356" data-original-width="1920" height="452" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi70ggMDLAxt1XYTBugVSKE0LC4ZH512gg1vE_lRQCMV-f4DkhcDVoj1Di5I_xIIcc0VBCMo_ZFD0_S85gN34gkYd7e4mThhcWVbk53EkkCXGBbMyonj_D23KFW4-yQOPFNGsSsTXI-I0joowPc4HYqO60DPsN4bsuwaidwBrN3XKOXkCPaDWwH7Sx5/w640-h452/Scientists%20Confirm%20Discovery%20of%20%E2%80%98Hottest%20Rock%20on%20Earth%E2%80%99%20(1).jpg" title="A sample of glass that recorded at 2,370 degrees Celsius. Image credit: Gavin Tolometti." width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Scientists Confirm Discovery of ‘Hottest Rock on Earth’. A sample of glass that recorded at 2,370 degrees Celsius. Photo credit: Gavin Tolometti.<br /><br /></td></tr></tbody></table><br /><p></p><p style="text-align: left;"><span style="font-family: georgia;">Cubic zirconia from the 28-km- (17.4-mile) wide Mistastin Lake crater in Canada required >2,370 degrees Celsius melt, which is hottest recorded on Earth’s surface.</span> <br /></p><p style="text-align: left;">If there was ever any doubt the 2011 discovery by a post-doctoral student was indeed the hottest rock on Earth, new findings from a Western-led research team are putting that uncertainty to rest.<br /><br />Eleven years after researchers from Western unearthed what was then perceived as the hottest rock on Earth, a recent study found four additional zircon grains – a hard mineral commonly known as a substitute for diamonds – that confirmed the previous rock’s record-high temperature of 2,370 C.<br /><br />The study, published in the journal Earth and Planetary Science Letters, was led by Earth sciences post-doctoral student Gavin Tolometti and co-authors: Timmons Erickson from NASA Johnson Space Center, Gordon Osinski and Catherine Neish from the department of Earth sciences; and Cayron Cyril from the Laboratory of Thermomechanical Metallurgy.<br /><br />In 2011, then PhD student Michael Zanetti was working with Osinski at the Mistastin Lake impact crater in Labrador when he found a glass rock that contained small zircon grains frozen inside it. That rock was later analyzed and found to have been formed at 2,370 C temperature as a result of an asteroid impact. These findings were shared in a study published in 2017.<br /></p><div style="margin: 0px auto; width: 100%;">
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</div><br />In their own study using samples collected between 2009 and 2011, Tolometti and his colleagues were able to find four additional zircon grains that confirmed the 2011 discovery to be true. They researchers also located and found evidence in a different location within the same impact structure that the melt rock – rocks created after rock and soil melt into liquid after a meteor strikes – was differently superheated in more than one location, to a greater degree than previously theorized.<br /><br />“The biggest implication is that we are getting a much better idea of how hot these impact melt rocks are, which initially formed when the meteorite struck the surface, and it gives us a much better idea of the history of the melt and how it cooled in this particular crater,” Tolometti said.<br /><br />“It can also give us insight to study the temperature and melts in other impact craters.”<br /><br />Tolometti also noted that most of the preserved evidence, such as glass samples and impact melt samples, were found close to the crater floor. By applying this knowledge to other impact craters, researchers might be able to find more evidence of the temperature conditions found in other craters but in less extensive studies.<br /><br />“We’re starting to realize that if we’re wanting to find evidence of temperatures this high, we need to look at specific regions instead of randomly selecting across an entire crater,” he said.<br /><p></p><h4 style="text-align: left;">Other discovery</h4><p style="text-align: left;">The paper also noted this is the first time reidites – a mineral formed when zircon undergoes high pressure and temperatures – have been discovered at this site. The team found three reidites that were still preserved in the zircon grains, and evidence that another two were once present but had crystallized when temperatures had exceeded 1,200 C, at which point the reidite was no longer stable.<br /><br />This mineral allows researchers to better constrain the pressure conditions indicating that there may have been a peak pressure condition around 30 to potentially above 40 gigapascals. These are the pressure conditions that were created when the meteorite struck the surface at that time. The closer something is to the impact event, the higher the pressure is going to be. Certain minerals that have been compressed greatly by this event – referred to as ‘shocked’ – leave behind structures that can be studied.<br /><br />“Considering how big the reidite was in our samples, we knew the minimum pressure it probably recorded was about 30 gigapascals. But since there is a lot of reidites still present within some of these grains, we know that it could even be above 40 gigapascals,” Tolometti explained.<br /><br />This provides a better idea of the amount of pressure produced outside of the melting zone when the meteorite struck the surface. The melting zone will, by default, have pressures usually above 100 gigapascals, at which point a rock will completely melt or vaporize outside of those conditions.<br /></p><h4 style="text-align: left;">Research expansion</h4><p style="text-align: left;">The research group plans to expand this work to other impact craters on Earth. Some PhD students will be working with Osinski to look at other craters such as Lac Wiyâshâkimî (Clearwater West crater) in Quebec. Tolometti is also looking to expand this work and look at Apollo lunar samples that were brought back to Earth, which have plenty of evidence to form from impact craters.<br /><br />“If we were to find evidence of microstructures in zircon grains or other grains in pressure conditions, we could get a much better idea of what impact cratering processes are like on the moon,” he said.<br /><br />“It can be a step forward to try and understand how rocks have been modified by impact cratering across the entire solar system. This data can then be applied into impact models to improve the results that we get.” </p><p style="text-align: left;"><br /></p><p style="text-align: left;"><i><u><span style="font-family: trebuchet;">The above story is based on <a href="https://news.westernu.ca/2022/04/western-researcher-confirms-hottest-rock-on-record/" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.uwo.ca/img/homepage/2017/logo-western-crest-ftr.svg" rel="nofollow" target="_blank">Western University.</a></span></u></i><br /></p>

Scientists Confirm Discovery of ‘Hottest Rock on Earth’

Scientists Confirm Discovery of ‘Hottest Rock on Earth’. A sample of glass that recorded at 2,370 degrees Celsius. Photo credit: Gavin Tolom...

Oldest Microfossils On Earth Found In Canada

Earth History, Fossils 10:35 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://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjBGHbHc9fxAXyJE7MAQxEf-1SDH5Ytha9hs48sklS5v91VamZVM59NiLn8v7YX5JC-9v9BOeGcEQ1bcWI0JmVZaND0FiFcyjgMiWzLniwZqgBDA8IXPZ5qSPLGxzUDTKZRvaTlQePKmwoh76r2zOwp0V7zKI_KU_Tc-4oB-HXTGqPO2GWV1yNKsPco/s1171/Oldest%20Microfossils%20On%20Earth%20Found%20In%20Canada%20(1).jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="878" data-original-width="1171" height="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjBGHbHc9fxAXyJE7MAQxEf-1SDH5Ytha9hs48sklS5v91VamZVM59NiLn8v7YX5JC-9v9BOeGcEQ1bcWI0JmVZaND0FiFcyjgMiWzLniwZqgBDA8IXPZ5qSPLGxzUDTKZRvaTlQePKmwoh76r2zOwp0V7zKI_KU_Tc-4oB-HXTGqPO2GWV1yNKsPco/w640-h480/Oldest%20Microfossils%20On%20Earth%20Found%20In%20Canada%20(1).jpg" title="Iron-rich chert from the Nuvvuagittuq Supracrustal Belt, Québec, Canada. Likely the red coloration ...PHOTO:  DOMINIC PAPINEAU" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Iron-rich chert from the Nuvvuagittuq Supracrustal Belt, Québec, Canada. Likely the red coloration PHOTO:  DOMINIC PAPINEAU<br /></td></tr></tbody></table> <br /></p><p>Diverse microbial life existed on Earth at least 3.75 billion years ago, suggests a new study led by UCL researchers that challenges the conventional view of when life began.  <br /><br />For the study, published in Science Advances, the research team analysed a fist-sized rock from Quebec, Canada, estimated to be between 3.75 and 4.28 billion years old. In an earlier Nature paper*, the team found tiny filaments, knobs and tubes in the rock which appeared to have been made by bacteria.  <br /><br />However, not all scientists agreed that these structures – dating about 300 million years earlier than what is more commonly accepted as the first sign of ancient life – were of biological origin.  <br /><br />Now, after extensive further analysis of the rock, the team have discovered a much larger and more complex structure – a stem with parallel branches on one side that is nearly a centimetre long – as well as hundreds of distorted spheres, or ellipsoids, alongside the tubes and filaments.  <br /><div style="width:100%;margin: 0px auto">
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</div><br />The researchers say that, while some of the structures could conceivably have been created through chance chemical reactions, the “tree-like” stem with parallel branches was most likely biological in origin, as no structure created via chemistry alone has been found like it. <br /><br />The team also provide evidence of how the bacteria got their energy in different ways. They found mineralised chemical by-products in the rock that are consistent with ancient microbes living off iron, sulphur and possibly also carbon dioxide and light through a form of photosynthesis not involving oxygen. <br /><br />These new findings, according to the researchers, suggest that a variety of microbial life may have existed on primordial Earth, potentially as little as 300 million years after the planet formed. <br /><br />Lead author Dr Dominic Papineau (UCL Earth Sciences, UCL London Centre for Nanotechnology, Centre for Planetary Sciences and China University of Geosciences) said: “Using many different lines of evidence, our study strongly suggests a number of different types of bacteria existed on Earth between 3.75 and 4.28 billion years ago.”  <br /><br />“This means life could have begun as little as 300 million years after Earth formed. In geological terms, this is quick – about one spin of the Sun around the galaxy.” <br /><br />“These findings have implications for the possibility of extraterrestrial life. If life is relatively quick to emerge, given the right conditions, this increases the chance that life exists on other planets.” <br /><br />For the study, the researchers examined rocks from Quebec’s Nuvvuagittuq Supracrustal Belt (NSB) that Dr Papineau collected in 2008. The NSB, once a chunk of seafloor, contains some of the oldest sedimentary rocks known on Earth, thought to have been laid down near a system of hydrothermal vents, where cracks on the seafloor let through iron-rich waters heated by magma. <br /><br />The research team sliced the rock into sections about as thick as paper (100 microns) in order to closely observe the tiny fossil-like structures, which are made of haematite, a form of iron oxide or rust, and encased in quartz. These slices of rock, cut with a diamond-encrusted saw, were more than twice as thick as earlier sections the researchers had cut, allowing the team to see larger haematite structures in them. <br /><br />They compared the structures and compositions to more recent fossils as well as to iron-oxidising bacteria located near hydrothermal vent systems today. They found modern-day equivalents to the twisting filaments, parallel branching structures and distorted spheres (irregular ellipsoids), for instance close to the Loihi undersea volcano near Hawaii, as well as other vent systems in the Arctic and Indian oceans. <br /><br />As well as analysing the rock specimens under various optical and Raman microscopes (which measure the scattering of light), the research team also digitally recreated sections of the rock using a supercomputer that processed thousands of images from two high resolution imaging techniques. The first technique was micro-CT, or microtomography, which uses X-rays to look at the haematite inside the rocks. The second was focused ion beam, which shaves away miniscule - 200 nanometre-thick - slices of rock, with an integrated electron microscope taking an image in-between each slice.  <br /><br />Both techniques produced stacks of images used to create 3D models of different targets. The 3D models then allowed the researchers to confirm the haematite filaments were wavy and twisted, and contained organic carbon, which are characteristics shared with modern-day iron-eating microbes. <br /><br />In their analysis, the team concluded that the haematite structures could not have been created through the squeezing and heating of the rock (metamorphism) over billions of years, pointing out that the structures appeared to be better preserved in finer quartz (less affected by metamorphism) than in the coarser quartz (which has undergone more metamorphism).<br /><br />The researchers also looked at the levels of rare earth elements in the fossil-laden rock, finding that they had the same levels as other ancient rock specimens. This confirmed that the seafloor deposits were as old as the surrounding volcanic rocks, and not younger imposter infiltrations as some have proposed. <br /><br />Prior to this discovery, the oldest fossils previously reported were found in Western Australia and dated at 3.46 billion years old, although some scientists have also contested their status as fossils, arguing they are non-biological in origin. <br /><br />The new study involved researchers from UCL Earth Sciences, UCL Chemical Engineering UCL London Centre for Nanotechnology, and the Centre for Planetary Sciences at UCL and Birkbeck College London, as well as from the U.S. Geological Survey, the Memorial University of Newfoundland in Canada, the Carnegie Institution for Science, the University of Leeds, and the China University of Geoscience in Wuhan.  </p><p> </p><p><i><u><span style="font-family: trebuchet;">The above story is based on <a href="https://www.nature.com/articles/nature21377" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.ucl.ac.uk/" rel="nofollow" target="_blank">University College London.</a></span></u></i><br /></p>

Oldest Microfossils On Earth Found In Canada

Iron-rich chert from the Nuvvuagittuq Supracrustal Belt, Québec, Canada. Likely the red coloration PHOTO: DOMINIC PAPINEAU Diverse microb...

Paleontologists Find Perfectly Preserved Dinosaur Fossils From the Day of the Asteroid Impact

Earth History, Fossils 10:05 PM

<p></p><p></p><p style="text-align: left;">Scientists believe they have been given an extraordinary view of the last day of the dinosaurs after they discovered the fossil of an animal they believe died that day.<br /><br />An upcoming BBC documentary looks at a slew of fossils found at the Tanis site in North Dakota. It includes the Thescelosaurus leg, seen in a video here, and the skin of a triceratops, pictured above.  <br /><br />The site is rich in well-preserved fossils, including fish, a turtle, and even the embryo of a flying pterosaur encased in an egg.<br /><br />Scientists believe that tiny glass-like particles of molten rock lodged in the gills of fish fossils found at the site were kicked up by the asteroid's explosive impact, the BBC said.<br /><br />"We've got so many details with this site that tells us what happened moment by moment. It's almost like watching it play out in the movies," Robert DePalma, a graduate student from the University of Manchester, UK, who leads the Tanis dig, told the BBC.<br /><br />Prof Phil Manning, DePalma's PhD supervisor at Manchester, told BBC Radio 4's Today program that the discovery was "absolutely bonkers" and something he "never dreamt in all my career."<br /><br /></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZhPl6OprlHsZY7WHNbwAHNyFLXn78yy06-WgoknrOAxmbDfdv_FuTan-hPgPcVihR7L4OQ-JnwOeqcEKBOlRAJCy54gbi0b7xw4tsKKpLm8cQD_YMPGMLksnCupklh70Jf6r6YtPRtScK5ZaoK8MMvvR5Xb1W9vo7jbe6x-cwfPC3OTuL-XGRsyuX/s1543/Paleontologists%20Find%20Perfectly%20Preserved%20Dinosaur%20Fossils%20From%20the%20Day%20of%20the%20Asteroid%20Impact.jpeg" style="margin-left: auto; margin-right: auto;"><img alt="Paleontologists Find Perfectly Preserved Dinosaur Fossils From the Day of the Asteroid Impact" border="0" data-original-height="1115" data-original-width="1543" height="289" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZhPl6OprlHsZY7WHNbwAHNyFLXn78yy06-WgoknrOAxmbDfdv_FuTan-hPgPcVihR7L4OQ-JnwOeqcEKBOlRAJCy54gbi0b7xw4tsKKpLm8cQD_YMPGMLksnCupklh70Jf6r6YtPRtScK5ZaoK8MMvvR5Xb1W9vo7jbe6x-cwfPC3OTuL-XGRsyuX/w400-h289/Paleontologists%20Find%20Perfectly%20Preserved%20Dinosaur%20Fossils%20From%20the%20Day%20of%20the%20Asteroid%20Impact.jpeg" title="Behind the scenes. Ian Kellett on location in Tanis filming the Triceratops skin whilst still in the ground. /BBC" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="background-color: #eeeeee;">Paleontologists Find Perfectly Preserved Dinosaur Fossils From the Day of the Asteroid Impact. Behind the scenes. Ian Kellett on location in Tanis filming the Triceratops skin whilst still in the ground. /BBC</span><br /></td></tr></tbody></table><p></p>
"The time resolution we can achieve at this site is beyond our wildest dreams. This really should not exist, and it's absolutely gobsmackingly beautiful," Manning said.<p></p><h4 style="text-align: left;"><span style="font-family: inherit;">A discovery so 'fabulous' it has attracted skepticism</span></h4><p style="text-align: left;">In the BBC documentary, Robert DePalma, a relative of film director Brian De Palma, can be seen sporting an Indiana Jones-style fedora and tan shirt.<br /><div style="margin: 0px auto; width: 100%;">
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</div><br />He christened the paleontological site "Tanis," the last resting place of the Ark of the Covenant in the 1981 film Raiders of the Lost Ark, per The New Yorker.<br /><br />The findings from Tanis, and the work of DePalma, have attracted controversy over the years. <br /><br />The New Yorker first wrote about the Tanis site in 2019 before presenting the findings in an academic journal. <br /><br />While paleontologists usually cede their rights and curation of the fossils to institutions, DePalma, who had collected few academic laurels until the discovery of the site, insists on contractual clauses that give him oversight over the specimens. He has controlled how the fossils are presented, per The New Yorker.<br /><br />In response to the article, Kate Wong, science editor of Scientific American, said in a 2019 tweet that the findings from the site "have met with a good deal of skepticism from the paleontology community."<br /><br />A few peer-reviewed papers have since been published, and the BBC said that the dig team promises more.<br /><br />The BBC also said that it has called outside consultants to verify the specimens. <br /><br />Prof Paul Barrett from London's Natural History Museum looked at the leg and said it was a Thescelosaurus that likely died "more or less instantaneously."<br /><br />"It's from a group that we didn't have any previous record of what its skin looked like, and it shows very conclusively that these animals were very scaly like lizards. They weren't feathered like their meat-eating contemporaries," Barrett told the BBC.<br /><br />However, Prof Steve Brusatte, an outside consultant on the documentary from the University of Edinburgh, told the BBC he was skeptical about the dinosaurs' findings for now and would like to see the hypotheses being subjected to the scrutiny of peer review. <br /><br />"Those fish with the spherules in their gills, they're an absolute calling card for the asteroid. But for some of the other claims – I'd say they have a lot of circumstantial evidence that hasn't yet been presented to the jury," he said.<br /><br />Prof Brusatte said that it is possible that some of the animals died before the asteroid strike but could have been exhumed and then buried again by the impact.<br /><br />But ultimately, Brussate said the quality of the fossils trumps the controversy about the event's timing. <br /><br />"For some of these discoveries, though, does it even matter if they died on the day or years before? The pterosaur egg with a pterosaur baby inside is super-rare; there's nothing else like it from North America. It doesn't all have to be about the asteroid."</p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"></p><p style="text-align: left;"></p><br /><i><u><span style="font-family: trebuchet;">This article was originally published by <a href="https://www.businessinsider.com/dinosaur-fossil-from-day-extinction-asteroid-hit-earth-scientists-claim-2022-4" rel="nofollow" target="_blank">Business Insider</a>.</span></u></i><br class="Apple-interchange-newline" />

Paleontologists Find Perfectly Preserved Dinosaur Fossils From the Day of the Asteroid Impact

Scientists believe they have been given an extraordinary view of the last day of the dinosaurs after they discovered the fossil of an animal...

Perfectly Preserved 310-Million-Year-Old Fossilized Brain Found

Earth History, Fossils 12:11 AM

<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://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEirMFUifv7vFXWJPhIKDso7h3EXUEV6S6-ExpvuaLOMdP7UNX3YaMydKDP-RTGiQ56KOW4JnT9_pGLKOgcnHxeX2Oitk6yZyBfz5493atiy_iNoxPKxbMh5Hy8PT2oviheJ_IezlbW7DzchGTvq6_yIjfSEabby8zF9BD7v5mdJtBvXMm-OvWZ_AleP/s1096/Perfectly%20Preserved%20310-Million-Year-Old%20Fossilized%20Brain%20Found.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="617" data-original-width="1096" height="360" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEirMFUifv7vFXWJPhIKDso7h3EXUEV6S6-ExpvuaLOMdP7UNX3YaMydKDP-RTGiQ56KOW4JnT9_pGLKOgcnHxeX2Oitk6yZyBfz5493atiy_iNoxPKxbMh5Hy8PT2oviheJ_IezlbW7DzchGTvq6_yIjfSEabby8zF9BD7v5mdJtBvXMm-OvWZ_AleP/w640-h360/Perfectly%20Preserved%20310-Million-Year-Old%20Fossilized%20Brain%20Found.jpg" title="Perfectly Preserved 310-Million-Year-Old Fossilized Brain Found" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">(A) Specimen of the fossil horseshoe crab Euproops danae from Mazon Creek, Illinois, USA, preserved with its brain intact. (B) Close-up of brain, as indicated by box in image (A). (C) Reconstruction of Euproops danae, including the position and anatomy of the brain. Credit: Russell Bicknell</td></tr></tbody></table><br /><p></p><p>Scientists say 310-million-year-old horseshoe crab fossil found in Illinois creek shows the crustacean species' brain has barely evolved since then<br /><br /></p><p>Unlike bones and shells, which can endure for millions of years, soft tissues are rarely preserved as fossils.<br /><br />Indeed, the fossil record of animal soft tissues, such as brains and other internal organs, is so limited that there are significant gaps in our understanding of the evolution and fossilization processes of these important anatomical features.<br /><br />A new study published today in the prestigious journal Geology has now closed some of these knowledge gaps. The study—by an international team of scientists, including UNE palaeontologists Dr. Russell Bicknell and Professor John Paterson—describes the delicate brain of an ancient aquatic arthropod and how it was preserved in such remarkable detail.<br /><br />Lead author, Dr. Bicknell, explains what makes the discovery of a 310-million-year-old horseshoe crab with its brain intact so special.<br /></p><div style="margin: 0px auto; width: 100%;">
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</div><br />"Most of our limited knowledge on prehistoric arthropod brains is derived from amber inclusions or Cambrian Burgess Shale-type fossil deposits."<br /><br />"Amber, or fossilized tree resin, often contains a variety of trapped organisms such as insects, preserving the most intricate details. Using sophisticated imaging technology, scientists are able to study these entombed creatures, including their tiny brains.<br /><br />"However, we are somewhat limited when studying these particular fossils, as the oldest arthropods in amber only date back to the Triassic Period, around 230 million years ago."<br /><br />Burgess Shale-type deposits from the Cambrian Period—typically around 500 to 520 million years in age—are much older than the amber and also preserve spectacular brain structures as carbon films in mudstone.<br /><br />"These Burgess Shale-type fossils are very important as they represent some of the oldest animals on Earth, and can inform us on their origins and earliest evolutionary history," Dr. Bicknell said.<br /><br />The team's new fossil effectively demonstrates that arthropod brains can be preserved in an entirely different way.<br /><br />Their specimen of the horseshoe crab, Euproops danae, comes from the world-famous Mazon Creek deposit of Illinois in the U.S.. Fossils from this deposit are preserved within concretions made of an iron carbonate mineral called siderite.<br /><br />"We have shown, for the first time, that the Mazon Creek animals were not only molded by the rapid formation of siderite that entombed their entire bodies, but also that the siderite quickly encased their internal soft tissues before they could decompose," co-author Professor Paterson said.<br /><br />"In our fossil, the brain of Euproops is replicated by a white-colored clay mineral called kaolinite. This mineral cast would have formed later within the void left by the brain, long after it had decayed. Without this conspicuous white mineral, we may have never spotted the brain."<br /><br />The study also reveals that the brain anatomy of horseshoe crabs has remained essentially unchanged throughout most of their evolutionary history.<br /><br />"The fossil's central nervous system is closely comparable to that of living horseshoe crabs and match up in their arrangement of nerves to the eyes and appendages. It also shows the same central opening for the esophagus to pass through. This is quite remarkable, given the substantial morphological and ecological diversification that has taken place in the group over the intervening 310 million years," Prof. Paterson said.<br /><br />"We have been given a rare glimpse into the prehistoric past, allowing us to further our understanding of the biology and evolution of these long-extinct animals."<p></p><p> </p><p><u><i> The above story is based on <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/soft-tissue-preservation" rel="nofollow" target="_blank">materials </a>provided by <a href="https://www.une.edu.au/" rel="nofollow" target="_blank">University of New England.</a></i></u><br /></p>

Perfectly Preserved 310-Million-Year-Old Fossilized Brain Found

(A) Specimen of the fossil horseshoe crab Euproops danae from Mazon Creek, Illinois, USA, preserved with its brain intact. (B) Close-up of b...

Geology In