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Life underground suited newly discovered dinosaur fine

Fona herzogae. Credit: Jorge Gonzales
Fona herzogae. Credit: Jorge Gonzales

The age of dinosaurs wasn’t conducted solely above ground. A newly discovered ancestor of Thescelosaurus shows evidence that these animals spent at least part of their time in underground burrows. The new species contributes to a fuller understanding of life during the mid-Cretaceous — both above and below ground.

The new dinosaur, Fona [/Foat’NAH/] herzogae lived 99 million years ago in what is now Utah. At that time, the area was a large floodplain ecosystem sandwiched between the shores of a massive inland ocean to the east and active volcanoes and mountains to the west. It was a warm, wet, muddy environment with numerous rivers running through it.

Paleontologists from North Carolina State University and the North Carolina Museum of Natural Sciences unearthed the fossil — and other specimens from the same species — in the Mussentuchit Member of the Cedar Mountain Formation, beginning in 2013. The preservation of these fossils, along with some distinguishing features, alerted them to the possibility of burrowing.

Fona was a small-bodied, plant-eating dinosaur about the size of a large dog with a simple body plan. It lacks the bells and whistles that characterize its highly ornamented relatives such as horned dinosaurs, armored dinosaurs, and crested dinosaurs. But that doesn’t mean Fona was boring.

Fona shares several anatomical features with animals known for digging or burrowing, such as large bicep muscles, strong muscle attachment points on the hips and legs, fused bones along the pelvis — likely to help with stability while digging — and hindlimbs that are proportionally larger than the forelimbs. But that isn’t the only evidence that this animal spent time underground.

“The bias in the fossil record is toward bigger animals, primarily because in floodplain environments like the Mussentuchit, small bones on the surface will often scatter, rot away, or become scavenged before burial and fossilization,” says Haviv Avrahami, Ph.D. student at NC State and digital technician for the new Dueling Dinosaurs program at the North Carolina Museum of Natural Sciences. Avrahami is first author of the paper describing the work.

“But Fona is often found complete, with many of its bones preserved in the original death pose, chest down with splayed forelimbs, and in exceptionally good condition,” Avrahami says. “If it had already been underground in a burrow before death, it would have made this type of preservation more likely.”

Lindsay Zanno, associate research professor at NC State, head of paleontology at the North Carolina Museum of Natural Sciences and corresponding author of the work, agrees.

“Fona skeletons are way more common in this area than we would predict for a small animal with fragile bones,” Zanno says. “The best explanation for why we find so many of them, and recover them in small bundles of multiple individuals, is that they were living at least part of the time underground. Essentially, Fona did the hard work for us, by burying itself all over this area.”

Although the researchers have yet to identify the subterranean burrows of Fona, the tunnels and chamber of its closest relative, Oryctodromeus, have been found in Idaho and Montana. These finds support the idea that Fona also used burrows.

The genus name Fona comes from the ancestral creation story of the Chamorro people, who are the indigenous populations of Guam and the Pacific Mariana Islands. Fo’na and Pontan were brother and sister explorers who discovered the island and became the land and sky. The species name honors Lisa Herzog, the paleontology operations manager at the North Carolina Museum of Natural Sciences, for her invaluable contributions and dedication to the field of paleontology.

“I wanted to honor the indigenous mythology of Guam, which is where my Chamorro ancestors are from,” Avrahami says. “In the myth, Fo’na became part of the land when she died, and from her body sprung forth new life, which to me, ties into fossilization, beauty, and creation. Fona was most likely covered in a downy coat of colorful feathers. The species name is for Lisa Herzog, who has been integral to all this work and discovered one of the most exceptional Fona specimens of several individuals preserved together in what was likely a burrow.”

Fona is also a distant relative of another famous North Carolina fossil: Willo, a Thescelosaurus neglectus specimen currently housed at the museum and also thought to have adaptations for a semifossorial — or partially underground — lifestyle, research that was published late in 2023 by Zanno and former NC State postdoctoral researcher David Button.

“T. neglectus was at the tail end of this lineage — Fona is its ancestor from about 35 million years prior,” Avrahami says.

The researchers believe Fona is key to expanding our understanding of Cretaceous ecosystems.

“Fona gives us insight into the third dimension an animal can occupy by moving underground,” says Avrahami. “It adds to the richness of the fossil record and expands the known diversity of small-bodied herbivores, which remain poorly understood despite being incredibly integral components of Cretaceous ecosystems.”

“People tend to have a myopic view of dinosaurs that hasn’t kept up with the science,” Zanno says. “We now know that dinosaur diversity ran the gamut from tiny arboreal gliders and nocturnal hunters, to sloth-like grazers, and yes, even subterranean shelterers.”

The work appears in The Anatomical Record. Peter Makovicky of the University of Minnesota and Ryan Tucker of Stellenbosch University also contributed to the work.

Reference:
Haviv M. Avrahami, Peter J. Makovicky, Ryan T. Tucker, Lindsay E. Zanno. A new semi‐fossorial thescelosaurine dinosaur from the Cenomanian‐age Mussentuchit Member of the Cedar Mountain Formation, Utah. The Anatomical Record, 2024; DOI: 10.1002/ar.25505

Note: The above post is reprinted from materials provided by North Carolina State University. Original written by Tracey Peake

Sixty-million-year-old grape seeds reveal how the death of the dinosaurs may have paved the way for grapes to spread

Lithouva - the earliest fossil grape from the Western Hemisphere, ~60 million years old from Colombia. Top figure shows fossil accompanied with CT scan reconstruction. Bottom shows artist reconstruction. Photos by Fabiany Herrera, art by Pollyanna von Knorring.
Lithouva – the earliest fossil grape from the Western Hemisphere, ~60 million years old from Colombia. Top figure shows fossil accompanied with CT scan reconstruction. Bottom shows artist reconstruction. Photos by Fabiany Herrera, art by Pollyanna von Knorring.

If you’ve ever snacked on raisins or enjoyed a glass of wine, you may, in part, have the extinction of the dinosaurs to thank for it. In a discovery described in the journal Nature Plants, researchers found fossil grape seeds that range from 60 to 19 million years old in Colombia, Panama, and Peru. One of these species represents the earliest known example of plants from the grape family in the Western Hemisphere. These fossil seeds help show how the grape family spread in the years following the death of the dinosaurs.

“These are the oldest grapes ever found in this part of the world, and they’re a few million years younger than the oldest ones ever found on the other side of the planet,” says Fabiany Herrera, an assistant curator of paleobotany at the Field Museum in Chicago’s Negaunee Integrative Research Center and the lead author of the Nature Plants paper. “This discovery is important because it shows that after the extinction of the dinosaurs, grapes really started to spread across the world.”

It’s rare for soft tissues like fruits to be preserved as fossils, so scientists’ understanding of ancient fruits often comes from the seeds, which are more likely to fossilize. The earliest known grape seed fossils were found in India and are 66 million years old. It’s not a coincidence that grapes appeared in the fossil record 66 million years ago-that’s around when a huge asteroid hit the Earth, triggering a massive extinction that altered the course of life on the planet. “We always think about the animals, the dinosaurs, because they were the biggest things to be affected, but the extinction event had a huge impact on plants too,” says Herrera. “The forest reset itself, in a way that changed the composition of the plants.”

Herrera and his colleagues hypothesize that the disappearance of the dinosaurs might have helped alter the forests. “Large animals, such as dinosaurs, are known to alter their surrounding ecosystems. We think that if there were large dinosaurs roaming through the forest, they were likely knocking down trees, effectively maintaining forests more open than they are today,” says Mónica Carvalho, a co-author of the paper and assistant curator at the University of Michigan’s Museum of Paleontology. But without large dinosaurs to prune them, some tropical forests, including those in South America, became more crowded, with layers of trees forming an understory and a canopy.

These new, dense forests provided an opportunity. “In the fossil record, we start to see more plants that use vines to climb up trees, like grapes, around this time,” says Herrera. The diversification of birds and mammals in the years following the mass extinction may have also aided grapes by spreading their seeds.

In 2013, Herrera’s PhD advisor and senior author of the new paper, Steven Manchester, published a paper describing the oldest known grape seed fossil, from India. While no fossil grapes had ever been found in South America, Herrera suspected that they might be there too.

“Grapes have an extensive fossil record that starts about 50 million years ago, so I wanted to discover one in South America, but it was like looking for a needle in a haystack,” says Herrera. “I’ve been looking for the oldest grape in the Western Hemisphere since I was an undergrad student.”

But in 2022, Herrera and his co-author Mónica Carvalho were conducting fieldwork in the Colombian Andes when a fossil caught Carvalho’s eye. “She looked at me and said, ‘Fabiany, a grape!’ And then I looked at it, I was like, ‘Oh my God.’ It was so exciting,” recalls Herrera. The fossil was in a 60-million-year-old rock, making it not only the first South American grape fossil, but among the world’s oldest grape fossils as well.

The fossil seed itself is tiny, but Herrera and Carvalho were able to identify it based on its particular shape, size, and other morphological features. Back in the lab, they conducted CT scans showing its internal structure that confirmed its identity. The team named the fossil Lithouva susmanii, “Susman’s stone grape,” in honor of Arthur T. Susman, a supporter of South American paleobotany at the Field Museum. “This new species is also important because it supports a South American origin of the group in which the common grape vine Vitis evolved,” says co-author Gregory Stull of the National Museum of Natural History.

The team conducted further fieldwork in South and Central America, and in the Nature Plants paper, Herrera and his co-authors ultimately described nine new species of fossil grapes from Colombia, Panama, and Perú, spanning from 60 to 19 million years old. These fossilized seeds not only tell the story of grapes’ spread across the Western Hemisphere, but also of the many extinctions and dispersals the grape family has undergone. The fossils are only distant relatives of the grapes native to the Western Hemisphere and a few, like the two species of Leea are only found in the Eastern Hemisphere today. Their places within the grape family tree indicate that their evolutionary journey has been a tumultuous one. “The fossil record tells us that grapes are a very resilient order. They’re a group that has suffered a lot of extinction in the Central and South American region, but they also managed to adapt and survive in other parts of the world,” says Herrera.

Given the mass extinction our planet is currently facing, Herrera says that studies like this one are valuable because they reveal patterns about how biodiversity crises play out. “But the other thing I like about these fossils is that these little tiny, humble seeds can tell us so much about the evolution of the forest,” says Herrera.

This study was authored by Fabiany Herrera (Field Museum), Mónica Carvalho (University of Michigan), Gregory Stull (National Museum of Natural History, Smithsonian Institution), Carlos Jarramillo (Smithsonian Tropical Research Institute), and Steven Manchester (Florida Museum of Natural History, University of Florida).

Reference:
Fabiany Herrera, Mónica R. Carvalho, Gregory W. Stull, Carlos Jaramillo, Steven R. Manchester. Cenozoic seeds of Vitaceae reveal a deep history of extinction and dispersal in the Neotropics. Nature Plants, 2024; DOI: 10.1038/s41477-024-01717-9

Note: The above post is reprinted from materials provided by Field Museum.

Newly discovered dinosaur boasts big, blade-like horns

Reconstruction of Lokiceratops in the 78-million-year-old swamps of northern Montana, as two Probrachylophosaurus move past in the background. Artwork by Fabrizio Lavezzi © Evolutionsmuseet, Knuthenborg
Reconstruction of Lokiceratops in the 78-million-year-old swamps of northern Montana, as two Probrachylophosaurus move past in the background. Artwork by Fabrizio Lavezzi © Evolutionsmuseet, Knuthenborg

What do you get when you cross Norse mythology with a 78-million-year-old ancestor to the Triceratops? Answer: Lokiceratops rangiformis, a plant-eating dinosaur with a very fancy set of horns.

The new dinosaur was identified and named by Colorado State University affiliate faculty member Joseph Sertich and University of Utah Professor Mark Loewen. The dinosaur’s name, announced today in the scientific journal PeerJ, translates roughly to “Loki’s horned face that looks like a caribou.”

Loewen and Sertich, co-lead authors of the PeerJ study, dubbed the new species Lokiceratops (lo-Kee-sare-a-tops) rangiformis because of the unusual, curving blade-like horns on the back of its frill — the shield of bone at the back of the skull — and the asymmetrical horns at the peak of the frill, reminiscent of caribou antlers.

“The dinosaur now has a permanent home in Denmark, so we went with a Norse god, and in the end, doesn’t it just really look like Loki with the curving blades?” Loewen said, referring to the trickster god’s weapon of choice.

Loewen, a paleontologist at the Natural History Museum of Utah, and Sertich, a paleontologist with the Smithsonian Tropical Research Institute, are both scientific consultants for the Museum of Evolution in Denmark, Lokiceratops’ new home.

“It’s one of those stories with a happy ending, where it didn’t go to somebody’s mansion,” Sertich said. “It ended up in a museum, where it will be preserved forever so people can study it and enjoy visiting it.”

New dinosaur discovery

Lokiceratops was discovered in 2019 in the badlands of northern Montana, two miles (3.2 kilometers) south of the U.S.-Canada border. Sertich and Loewen helped reconstruct the dinosaur from fragments the size of dinner plates and smaller. Once they had pieced the skull together, they realized the specimen was a new type of dinosaur.

Estimated to be 22 feet (6.7 meters) long and weigh 11,000 pounds (5 metric tonnes), Lokiceratops is the largest dinosaur from the group of horned dinosaurs called centrosaurines ever found in North America. It has the largest frill horns ever seen on a horned dinosaur and lacks the nose horn that is characteristic among its kin.

“This new dinosaur pushes the envelope on bizarre ceratopsian headgear, sporting the largest frill horns ever seen in a ceratopsian,” Sertich said in a press release announcing the dinosaur’s unveiling at the Natural History Museum of Utah, where a replica is displayed. “These skull ornaments are one of the keys to unlocking horned dinosaur diversity and demonstrate that evolutionary selection for showy displays contributed to the dizzying richness of Cretaceous ecosystems.”

Sertich likened dinosaur horns to feathers on birds. Birds use feather colors and patterns to differentiate their own species among other, similar species of birds.

“We think that the horns on these dinosaurs were analogous to what birds are doing with displays,” Sertich said. “They’re using them either for mate selection or species recognition.”

What Loki’s horns tell us about dinosaurs

Lokiceratops was excavated from the same rock layer as four other dinosaur species, indicating that five different dinosaurs lived side by side 78 million years ago in the swamps and coastal plains along the eastern shore of Laramidia, the western landmass of North America created when a seaway divided the continent. Three of these species were closely related but not found outside the region.

“It’s unheard-of diversity to find five living together, similar to what you would see on the plains of East Africa today with different horned ungulates,” Sertich said.

Unlike the broad range of large wild mammals that roam the U.S. West today, such as elk, these ancient animals were geographically limited, he added. Loki’s discovery provides evidence that these species evolved rapidly within a small area, a process sometimes seen in birds.

By the time Triceratops came onto the scene 12 million years later, regional differences had been homogenized into just two species of horned dinosaurs from Canada to Mexico — possibly in response to a more homogenous climate, Sertich said.

The study shows that dinosaur diversity has been underestimated and presents the most complete family tree of horned dinosaurs to date.

“Lokiceratops helps us understand that we only are scratching the surface when it comes to the diversity and relationships within the family tree of horned dinosaurs,” Loewen said.

Reference:
Mark A. Loewen, Joseph J. W. Sertich, Scott Sampson, Jingmai K. O’Connor, Savhannah Carpenter, Brock Sisson, Anna Øhlenschlæger, Andrew A. Farke, Peter J. Makovicky, Nick Longrich, David C. Evans. Lokiceratops rangiformis gen. et sp. nov. (Ceratopsidae: Centrosaurinae) from the Campanian Judith River Formation of Montana reveals rapid regional radiations and extreme endemism within centrosaurine dinosaurs. PeerJ, 2024; 12: e17224 DOI: 10.7717/peerj.17224

Note: The above post is reprinted from materials provided by Colorado State University. Original written by Jayme DeLoss.

Recent volcanic ‘fires’ in Iceland triggered by storage and melting in crust

Drone imagery of April 2024 eruption at Sundhnúkur, Iceland. Photo: Geoffrey Cook/Scripps Oceanography
Drone imagery of April 2024 eruption at Sundhnúkur, Iceland. Photo: Geoffrey Cook/Scripps Oceanography

Scientists from UC San Diego’s Scripps Institution of Oceanography have detected geochemical signatures of magma pooling and melting beneath the subsurface during the “Fagradalsfjall Fires,” that began on Iceland’s Reykjanes peninsula in 2021.

Continuous sampling of the erupted lavas from the Fagradalsfjall volcano enabled a detailed time-series analysis of geochemical signals. These show that the start of the eruption began with massive pooling of magma, contrasting initial hypothesis for magma ascent straight from the mantle.

Scripps Oceanography geologist James Day and his colleagues report on the analyses July 31 in the journal Nature.

“By collecting lavas in regular intervals, and then measuring their compositions in the laboratory, we can tell what’s feeding the volcano at depth,” said study lead Day. “It’s a bit like taking regular measurements of someone’s blood. In this case, the volcano’s ‘blood’ are the molten lavas that emanate so spectacularly from it.”

Day, students at Scripps Oceanography, and international colleagues have been studying basaltic lavas from other recent volcanic eruptions in addition to Iceland. These include the 2021 eruption of the Tajogaite volcano on the island of La Palma in the Canary Islands and the 2022 eruption of Mauna Loa in Hawai’i. They have found evidence for similar magma pooling beneath La Palma.

“What makes the Iceland eruption so remarkable is the huge signal of crust within the earliest lavas,” said Day. “Along with our studies from La Palma, it suggests crustal magma storage may be a common process involved in the run up to larger basaltic eruptions like those in Iceland or the Canary Islands. This information will be important for understanding volcanic hazard in the future,” he added, “as it may help to forecast volcanic activity.”

Previous studies had suggested that the Fagradalsfjall Fires erupted from the surface without interaction with the crust. Day’s team, including UC San Diego undergraduate student Savannah Kelly, used the isotopic composition of the element osmium to understand what was happening beneath the volcano.

“What’s useful about using osmium,” said Day, “is that one of its isotopes is produced by the radiogenic decay of another metal, rhenium. Because the elements behave differently during melting, one of the elements, rhenium, is enriched in Earth’s crust.” Day and colleagues took advantage of the distinct behaviors of rhenium and osmium to show that the early lavas from the Fagradalsfjall Fires were contaminated by crust.

Earth can be broken up into a series of layers. The deepest portion is the metallic core. The shallowest layers are the atmosphere, ocean, and the rocky crust. All human beings live on the crust, which is dominated by rock types such as granite or basalt like that found in Iceland’s lavas. In between the core and crust is the vast mantle of the Earth. This mantle layer is where melting occurs to produce the magmas feeding volcanoes like those in Iceland.

Previous works published on the recent volcanic eruptions on the Reykjanes Ridge had used other geochemical fingerprints to study the lavas. These fingerprints suggested only mantle contributions to the lavas. Osmium isotopes are highly sensitive to crust and enabled the unambiguous identification of its addition into the early lavas.

“The work began as undergraduate research experience for Savannah (Kelly) and we fully expected to see mantle signatures in the lavas throughout the eruption,” said Day. “You can imagine our astonishment when we were sitting in front of the mass spectrometer measuring the early samples and saw obvious signals of crust within them.”

The team analyzed lavas erupting from the Fagradalsfjall volcano in 2021 and in 2022. The 2021 lavas were contaminated by crust, the 2022 lavas were not. They conclude that the earliest lavas pooled in the crust and interaction with the crust may have helped trigger the eruption.

“After that, it appears that the magma of later eruptions used pre-existing pathways to get to the surface,” Day said.

Day and colleagues plan to continue their work on Iceland and other basaltic eruptions into the future. Previous eruptions on the Reykjanes peninsula have lasted for centuries.

“It seems that the volcanic ‘fires’ in Iceland will outlast me,” Day said. “The eruptions that are likely to continue there will provide a treasure trove of important scientific information on how volcanoes work and their associated hazards. Our study shows that the beginning of the eruption was not just visually spectacular, but was also geochemically so.”

Besides Day and Kelly, Geoffrey Cook of Scripps Oceanography, William Moreland and Thor Thordarsson from the University of Iceland, and Valentin Troll from Uppsala University in Sweden were involved in the research. The National Science Foundation (NSF) Petrology and Geochemistry program partly funded the research.

Reference:
James M. D. Day, Savannah Kelly, Valentin R. Troll, William M. Moreland, Geoffrey W. Cook, Thor Thordarson. Deep crustal assimilation during the 2021 Fagradalsfjall Fires, Iceland. Nature, 2024; DOI: 10.1038/s41586-024-07750-0

Note: The above post is reprinted from materials provided by University of California – San Diego. Original written by Robert Monroe

A blue miracle: How sapphires formed in volcanoes

A sapphire from sediment in the Kyll, a river in the western Eifel. The crystal measures approximately 0.9 mm in diameter. | © Sebastian Schmidt
A sapphire from sediment in the Kyll, a river in the western Eifel. The crystal measures approximately 0.9 mm in diameter. | © Sebastian Schmidt

Sapphires are among the most precious gems, yet they consist solely of chemically “contaminated” aluminum oxide, or corundum. Worldwide, these characteristically blue-colored crystals are mainly found in association with silicon-poor volcanic rocks. This connection is widely assumed to result from sapphires originating in deep crustal rocks and accidentally ending up on the Earth’s surface as magma ascended. Through geochemical analyses, geoscientists at Heidelberg University have shown that the millimeter-sized sapphire grains found in the Eifel (Germany) formed in association with volcanism.

The Eifel is a volcanic region in the center of Europe where magma from the Earth’s mantle has been penetrating the overlying crust for nearly 700,000 years. The melts are poor in silicon dioxide but rich in sodium and potassium. Magmas similar in composition worldwide are known for their abundance of sapphire. Why this extremely rare variant of corundum is frequently found in this type of volcanic deposit has been a mystery until now. “One explanation is that sapphire in the Earth’s crust originates from previously clayey sediments at very high temperatures and pressure and the ascending magmas simply form the elevator to the surface for the crystals,” explains Prof. Dr Axel Schmitt, a researcher at Curtin University in Perth (Australia) who is investigating isotope geology and petrology as an honorary professor at the Institute of Earth Sciences at Heidelberg University — his former home institution.

To test this assumption, the researchers examined a total of 223 sapphires from the Eifel. They found a portion of these millimeter-sized crystals in rock samples collected from volcanic deposits in the numerous quarries in the region. Most of the sapphires, however, come from river sediments. “Like gold, sapphire is very weathering-resistant compared to other minerals. Over protracted time periods, the grains are washed out of the rock and deposited in rivers. Because of their high density, they are easy to separate from lighter sediment components using a gold pan,” explains Sebastian Schmidt, who conducted the studies as part of his master’s degree at Heidelberg University.

The researchers determined the age of the sapphires from the Eifel using the uranium-lead method on mineral inclusions in the sapphire using a secondary ion mass spectrometer that could also identify the composition of oxygen isotopes. The different relative abundances of the light isotope O-16 and the heavy isotope O-18 provide information on the origin of the crystals like a fingerprint. Deep crustal rocks have more O-18 than melts from the Earth’s mantle. As the age determinations show, the sapphires in the Eifel formed at the same time as the volcanism. In part, they inherited the isotopic signature of the mantle melts, which were contaminated by heated and partially melted crustal rock at a depth of about five to seven kilometers. Other sapphires originated in contact with the subterranean melts, whereby melts permeated the adjacent rock and thus triggered sapphire formation. “In the Eifel, both magmatic and metamorphic processes, in which temperature changed the original rock, played a role in the crystallization of sapphire,” states Sebastian Schmidt.

The research results were published in the journal “Contributions to Mineralogy and Petrology.” Support for the work came from the Dr. Eduard Gübelin Association for Research and Identification of Precious Stones in Switzerland as well as the German Research Foundation.

Reference:

Sebastian Schmidt, Andreas Hertwig, Katharina Cionoiu, Christof Schäfer, Axel K. Schmitt. Petrologically controlled oxygen isotopic classification of cogenetic magmatic and metamorphic sapphire from Quaternary volcanic fields in the Eifel, Germany. Contributions to Mineralogy and Petrology, 2024; 179 (6) DOI: 10.1007/s00410-024-02136-x

Note: The above post is reprinted from materials provided by Heidelberg University.

New study supports stable mantle chemistry dating back to Earth’s early geologic history and over its prodigious evolution

A thin slice of the ancient rocks collected from Gakkel Ridge near the North Pole, photographed under a microscope and seen under cross-polarized light. Field width ~ 14mm.Credit: E. Cottrell, Smithsonian.
A thin slice of the ancient rocks collected from Gakkel Ridge near the North Pole, photographed under a microscope and seen under cross-polarized light. Field width ~ 14mm.
Credit: E. Cottrell, Smithsonian.

A new analysis of rocks thought to be at least 2.5 billion years old by researchers at the Smithsonian’s National Museum of Natural History helps clarify the chemical history of Earth’s mantle — the geologic layer beneath the planet’s crust. The findings hone scientists’ understanding of Earth’s earliest geologic processes, and they provide new evidence in a decades-long scientific debate about the geologic history of Earth. Specifically, the results provide evidence that the oxidation state of the vast majority of Earth’s mantle has remained stable through geologic time and has not undergone major transitions, contrary to what has been suggested previously by other researchers.

“This study tells us more about how this special place in which we live came to be the way it is, with its unique surface and interior that have allowed life and liquid water to exist,” said Elizabeth Cottrell, chair of the museum’s department of mineral sciences, curator of the National Rock Collection and co-author of the study. “It’s part of our story as humans because our origins all trace back to how Earth formed and how it has evolved.”

The study, published today in the journal Nature, centered on a group of rocks collected from the seafloor that possessed unusual geochemical properties. Namely, the rocks show evidence of having melted to an extreme degree with very low levels of oxidation; oxidation is when an atom or molecule loses one or more electrons in a chemical reaction. With the help of additional analyses and modeling, the researchers used the unique properties of these rocks to show that they likely date back to at least 2.5 billion years ago during the Archean Eon. Further, the findings show that the Earth’s mantle has overall retained a stable oxidation state since these rocks formed, in contrast to what other geologists have previously theorized.

“The ancient rocks we studied are 10,000 times less oxidized than typical modern mantle rocks, and we present evidence that this is because they melted deep in the Earth during the Archean, when the mantle was much hotter than it is today,” Cottrell said. “Other researchers have tried to explain the higher oxidation levels seen in rocks from today’s mantle by suggesting that an oxidation event or change has taken place between the Archean and today. Our evidence suggests that the difference in oxidation levels can simply be explained by the fact that Earth’s mantle has cooled over billions of years and is no longer hot enough to produce rocks with such low oxidation levels.”

The research team — including lead study author Suzanne Birner who completed a pre-doctoral fellowship at the National Museum of Natural History and is now an assistant professor at Berea College in Kentucky — began their investigation to understand the relationship between Earth’s solid mantle and modern seafloor volcanic rocks. The researchers started by studying a group of rocks that were dredged from the seafloor at two oceanic ridges where tectonic plates are spreading apart and the mantle is churning up to the surface and producing new crust.

The two places the studied rocks were collected from, the Gakkel Ridge near the North Pole and the Southwest Indian Ridge between Africa and Antarctica, are two of the slowest-spreading tectonic plate boundaries in the world. The slow pace of the spreading at these ocean ridges means that they are relatively quiet, volcanically speaking, compared to faster spreading ridges that are peppered with volcanoes such as the East Pacific Rise. This means that rocks collected from these slow-spreading ridges are more likely to be samples of the mantle itself.

When the team analyzed the mantle rocks they collected from these two ridges, they discovered they had strange chemical properties in common. First, the rocks had been melted to a much greater extent than is typical of Earth’s mantle today. Second, the rocks were much less oxidized than most other samples of Earth’s mantle.

To achieve such a high degree of melting, the researchers reasoned that the rocks must have melted deep in the Earth at very high temperatures. The only period of Earth’s geologic history known to include such high temperatures was between 2.5 and 4 billion years ago during the Archean Eon. Consequently, the researchers inferred that these mantle rocks may have melted during the Archean, when the inside of the planet was 360-540 degrees Fahrenheit (200-300 degrees Celsius) hotter than it is today.

Being so extremely melted would have protected these rocks from further melting that could have altered their chemical signature, allowing them to circulate in Earth’s mantle for billions of years without significantly changing their chemistry.

“This fact alone doesn’t prove anything,” Cottrell said. “But it opens the door to these samples being genuine geologic time capsules from the Archean.”

To explore the geochemical scenarios that might explain the low oxidation levels of the rocks collected at Gakkel Ridge and the Southwest Indian Ridge, the team applied multiple models to their measurements. The models revealed that the low oxidation levels they measured in their samples could have been caused by melting under extremely hot conditions deep in the Earth.

Both lines of evidence backed the interpretation that the rocks’ atypical properties represented a chemical signature from having melted deep in the Earth during the Archean, when the mantle could produce extremely high temperatures.

Previously, some geologists have interpreted mantle rocks with low oxidation levels as evidence that the Archean Earth’s mantle was less oxidized and that through some mechanism it has become more oxidized over time. Proposed oxidation mechanisms include a gradual increase in oxidation levels due to a loss of gasses to space, recycling of old seafloor by subduction and ongoing participation of Earth’s core in mantle geochemistry. But, to date, proponents of this view have not coalesced around any one explanation.

Instead, the new findings support the view that the oxidation level of Earth’s mantle has been largely steady for billions of years, and that the low oxidation seen in some samples of the mantle were created under geologic conditions the Earth can no longer produce because its mantle has since cooled. So, instead of some mechanism making Earth’s mantle more oxidized over billions of years, the new study argues that the high temperatures of the Archean made parts of the mantle less oxidized. Because Earth’s mantle has cooled since the Archean, it cannot produce rocks with super low oxidation levels anymore. Cottrell said the process of the planet’s mantle cooling provides a much simpler explanation: Earth simply does not make rocks like it used to.

Cottrell and her collaborators are now seeking to better understand the geochemical processes that shaped the Archean mantle rocks from the Gakkel Ridge and the Southwest Indian Ridge by simulating in the lab the extremely high pressures and temperatures found in the Archean.

This research contributes to the museum’s Our Unique Planet initiative. As a public-private research partnership, Our Unique Planet investigates what sets Earth apart from its cosmic neighbors by exploring the origins of the planet’s oceans and continents, as well as how minerals may have served as templates for life.

In addition to Birner and Cottrell, Fred Davis of the University of Minnesota Duluth and Jessica Warren of the University of Delaware were co-authors of the study.

The research was supported by the Smithsonian and the National Science Foundation.

Reference:

Suzanne K. Birner, Elizabeth Cottrell, Fred A. Davis, Jessica M. Warren. Deep, hot, ancient melting recorded by ultralow oxygen fugacity in peridotites. Nature, 2024; 631 (8022): 801 DOI: 10.1038/s41586-024-07603-w.

Note: The above post is reprinted from materials provided by Smithsonian.

Scientists discover missing piece in climate models

Photo-like satellite image of southern Greenland on the afternoon of September 4, 2022. Bare, dirty ice at the margin of the ice sheet appears gray. Snow-covered ice is bright white. Pale blue ribbons and circles are lakes, rivers and ponds of melt water. NASA image from Worldview
Photo-like satellite image of southern Greenland on the afternoon of September 4, 2022. Bare, dirty ice at the margin of the ice sheet appears gray. Snow-covered ice is bright white. Pale blue ribbons and circles are lakes, rivers and ponds of melt water. NASA image from Worldview

As the planet continues to warm due to human-driven climate change, accurate computer climate models will be key in helping illuminate exactly how the climate will continue to be altered in the years ahead.

In a study published in the Journal of Geophysical Research: Atmospheres, a team led by researchers from the UC Irvine Department of Earth System Science and the University of Michigan Department of Climate and Space Sciences and Engineering reveal how a climate model commonly used by geoscientists currently overestimates a key physical property of Earth’s climate system called albedo, which is the degree to which ice reflects planet-warming sunlight into space.

“We found that with old model versions, the ice is too reflective by about five percent,” said Chloe Clarke, a project scientist in UC Irvine professor Charlie Zender’s group.

“Ice reflectivity was much too high.”

The amount of sunlight the planet receives and reflects is important for estimating just how much the planet will warm in the coming years.

Previous versions of the model, called the Energy Exascale Earth System Model (E3SM), overestimated albedo because they did not account for what Clarke described as the microphysical properties of ice in a warming world.

Those properties include the effects things like algae and dust have on albedo.

Dark-colored algae and dust can make snow and ice less reflective and less able to reflect sunlight.

To do the analysis, Clarke and her team studied satellite data to track the albedo of the Greenland Ice Sheet.

They found that E3SM reflectivity overestimates the reflectivity of the ice sheet, “meaning the model estimates less melt than what would be expected from the ice microphysical properties,” said Clarke.

But with the new ice reflectivity incorporated into the model, the Greenland Ice Sheet is melting at a rate of about six gigatons more than in older model versions.

This is based on albedo measurements that are more consistent with satellite observations.

Clarke hopes her team’s study stresses the importance of the seemingly minuscule properties that can have far-reaching consequences for the overall climate.

“I think our work is going to help models do a much better job of helping us capture snow and ice-related climate feedbacks,” she said.

Next, Clarke wants to study different icy parts of the planet to gauge how widespread the albedo discrepancy is in E3SM.

“Our next steps are to get it so it is functional globally and not just valid over Greenland,” said Clarke, who also intends to compare the new Greenland Ice Sheet melt rates to observations to measure how much more accurate the new ice albedo is. “It would be useful to apply it to glaciers in places like the Andes and Alaska.”

Additional authors include Raf Antwerpen (Lamont-Doherty Earth Observatory), Mark G. Flanner (University of Michigan), Adam Schneider (National Oceanic and Atmospheric Administration), Marco Tedesco (Lamont-Doherty Earth Observatory) and Charlie S. Zender (UC Irvine). Funding information is listed in the study.

Reference:

C. A. Whicker‐Clarke, R. Antwerpen, M. G. Flanner, A. Schneider, M. Tedesco, C. S. Zender. The Effect of Physically Based Ice Radiative Processes on Greenland Ice Sheet Albedo and Surface Mass Balance in E3SM. Journal of Geophysical Research: Atmospheres, 2024; 129 (7) DOI: 10.1029/2023JD040241

Note: The above post is reprinted from materials provided by University of California – Irvine.

Hot traces in rock

Porous dolomite rock with cavities that would be ideal for geothermal utilisation.© RUB, Marquard
Porous dolomite rock with cavities that would be ideal for geothermal utilisation.
© RUB, Marquard

Rocks undergo changes over millions of years. Yet it is possible to extract information from them about the climate at the time of their formation.

Fluids circulating underground change rocks over the course of time. These processes must be taken into account if they are to be used as a climate archive. In collaboration with international colleagues, Dr. Mathias Müller from the Sediment and Isotope Geology research group at Ruhr University Bochum, Germany, has used 380-million-year-old limestones from Hagen-Hohenlimburg to show in detail which climate information is still preserved in the rock. What’s more, his analyses allow him to draw conclusions about how suitable the rock is today for deep geothermal use. The results of his research have been published in the journal Geochimica et Cosmochimica Acta on July 1, 2024.

Climate archive in the rock

In order to gain a better understanding of today’s climate, it can help to look into the past. Researchers use so-called proxies for this purpose: indirect indicators of the climate in natural archives such as ice cores, tree rings or dripstones. “If we want to learn anything about the climate several million or even billions of years ago, we examine sedimentary rocks that may even have stored the seawater temperature from hundreds of millions of years ago,” explains Mathias Müller.

One thing that can make this type of far-reaching climate research considerably more difficult is the subsequent change in the climate signatures stored in these rocks. This process is called diagenesis. It begins shortly after sediment deposition in seawater and can continue to this day. “Very old rocks are usually buried to depths of several kilometers,” says Mathias Müller. “Changes in climate information are then caused by hot fluids circulating at depth.” Where they can penetrate the rock, they often lead to recrystallization or new mineral growth in the rock. In addition, when rocks are lifted from the depths to the earth’s surface, they are affected by the weather. This so-called meteoric diagenesis can also impact old climate information or render it completely useless.

From the shallow sea to the mountains

Together with an international research team, Mathias Müller reconstructed in detail which climate information from the shallow sea during the Devonian period is still stored in the rock in the Hagen-Hohenlimburg area and by which processes and under which conditions it has since been changed. The researchers analyzed numerous systematically collected rock samples from the Steltenberg quarry using petrographic and geochemical methods.

“We were surprised that the changes in the rock enabled us to identify a large number of significant geological events, such as the opening of the North Atlantic in the Jurassic and the onset of the folding and subsequent uplift of the Alps hundreds of kilometers away since the late Cretaceous period,” lists Mathias Müller. He considers radiometric uranium-lead dating to be the key to the chronological classification of the so-called overprinting events stored in the rock. “We were particularly pleased to discover during our research that climate information from the Devonian period can still be found even in heavily overprinted rocks,” stresses the researcher.

From climate research to geothermal energy

The findings of the study are also of interest when it comes to the exploitation of rocks for deep geothermal energy, which could be a contributing factor to the energy transition. Predicting which conditions will be encountered in which areas of the subsurface has been a major challenge for researchers to date. “Particularly in carbonate rocks, diagenetic overprinting can lead to both precipitation and dissolution phenomena in the rock, which can have a dramatic effect on the potential viability of geothermal energy,” says Mathias Müller.

The results of the current study allow tentative optimistic conclusions that some of the characterized processes in the deeper subsurface may have increased the usability for geothermal energy. Together with researchers from the Fraunhofer Research Institution for Energy Infrastructures and Geothermal Energy IEG and the Geological Survey of North Rhine-Westphalia, Mathias Müller currently aims to find out which implications the findings from the earth’s surface have for the applicability of geothermal energy at depth.

Reference:

M. Mueller, B.F. Walter, R.J. Giebel, A. Beranoaguirre, P.K. Swart, C. Lu, S. Riechelmann, A. Immenhauser. Towards a better understanding of the geochemical proxy record of complex carbonate archives. Geochimica et Cosmochimica Acta, 2024; 376: 68 DOI: 10.1016/j.gca.2024.04.029

Note: The above post is reprinted from materials provided by Ruhr-University Bochum. Original written by Meike Drießen; translated by Donata Zuber.

Organic material from Mars reveals the likely origin of life’s building blocks

Daybreak at the Gale Crater on Mars where organic material was found Photo: NASA/JPL-Caltech/MSSS
Daybreak at the Gale Crater on Mars where organic material was found Photo: NASA/JPL-Caltech/MSSS

Two samples from Mars together deliver the “smoking gun” in a new study showing the origin of Martian organic material. The study presents solid evidence for a prediction made over a decade ago by University of Copenhagen researchers that could be key to understanding how organic molecules, the foundation of life, were first formed here on Earth.

In a meteor crater on the red planet, a solitary robot is moving about. Right now it is probably collecting soil samples with a drill and a robotic arm, as it has quite a habit of doing. NASA’s Curiosity rover has been active on Mars as the extended arm of science for nearly 12 years, and it continues to make discoveries that surprise and challenge scientists’ understanding of both Mars and our own world here on Earth.

Most recently, the discovery of sedimentary organic material with particular properties has had many researchers scratching their heads. The properties of these carbon-based materials, in particular the ratio of its carbon isotopes, surprised researchers.

Organic materials with such properties, if found on Earth, would typically be a sign of microorganisms, but they can also be the result of non-biological, chemical processes. The find obviously had researchers scrambling for a clear answer, but nothing seemed to fit.

However, for the research collaboration behind a new study published in Nature Geoscience, there has been little hair scratching and much enthusiasm.

In fact, the discovery on Mars provided the missing piece that made everything fall into place for this group of researchers from the University of Copenhagen and the Tokyo Institute of Technology.

As co-author and chemistry professor Matthew Johnson puts it, it is “the smoking gun” needed to confirm a decade old theory of his about so-called photolysis in Mars’ atmosphere.

With the Curiosity sample, the new research is able to prove with reasonable certainty that the Sun broke down CO2 in the Martian atmosphere billions of years ago — as the old theory predicted. And that the resulting carbon monoxide gradually reacted with other chemicals in the atmosphere synthesizing complex molecules — and thus providing Mars with organic materials.

“Such carbon-based complex molecules are the prerequisite of life, the building blocks of life one might say. So, this it is a bit like the old debate about which came first, the chicken or the egg. We show that the organic material found on Mars has been formed through atmospheric photochemical reactions — without life that is. This is the ‘egg’, a prerequisite of life. It still remains to be shown whether or not this organic material resulted in life on the Red Planet.” said Johnson and continued:

“Additionally because Earth, Mars and Venus had very similar CO2 rich atmospheres long ago when this photolysis took place, it can also prove important for our understanding of how life began on Earth,” said Professor Matthew Johnson from Department of Chemistry at University of Copenhagen.

Two pieces separated by 50 Million Kilometers — one puzzle solved

12 years ago Johnson and two colleagues used simulations based on quantum mechanics to determine what happens when a CO2 rich atmosphere is exposed to the UV-light of the Sun, in a process known as photolysis.

Basically, on Mars around 20% of the CO2 is split into oxygen and carbon monoxide. But carbon has two stable isotopes: carbon-12 and carbon-13. Usually they are present in a ratio of one carbon-13 for every 99 carbon-12. However, photolysis works faster for the lighter carbon-12, so the carbon monoxide produced by photolysis has less carbon-13 (is depleted), and the left over CO2 has more (is enriched).

Because of this, Johnson and his colleagues were able to make very precise predictions of the ratio of carbon isotopes after photolysis. And this gave them two distinctive fingerprints to look for. One of these was identified in a different Martian sample, years ago.

“We actually have a piece of Mars here on Earth, which was knocked off that planet by a meteorite, and then became one itself, when it landed here on Earth. This meteorite, called Allan Hills 84001 for the place in Antarctica where it was found, contains carbonate minerals that form from CO2 in the atmosphere. The smoking gun here is that the ratio of carbon isotopes in it exactly matches our predictions in the quantum chemical simulations, but there was a missing piece in the puzzle. We were missing the other product of this chemical process to confirm the theory, and that’s what we’ve now obtained,” says Matthew Johnson.

The carbon in the Allan Hills meteorite is enriched in carbon-13, which makes it the mirror image of the depletion in carbon-13 that has now been measured in the organic material found by Curiousity on Mars.

The new study has thus linked data from two samples, which researchers believe have the same origin in Mars’ childhood but were found more than 50 million kilometers apart.

“There is no other way to explain both the carbon-13 depletion in the organic material and the enrichment in the Martian meteorite, both relative to the composition of volcanic CO2 emitted on Mars, which has a constant composition, similar as for Earth’s volcanos, and serves as a baseline,” said Johnson

Hope to find the same evidence on Earth

Because the organic material contains this isotopic “fingerprint” of where it came from, researchers are able to trace the source of the carbon in the organic material to the carbon monoxide formed by photolysis in the atmosphere. But this also reveals a lot about what happened to it in between.

“This shows that carbon monoxide is the starting point for the synthesis of organic molecules in these kinds of atmospheres. So we have an important conclusion about the origin of life’s building blocks. Although so far only on Mars,” said Matthew Johnson.

Researchers hope to find the same isotopic evidence on Earth, but this has yet to happen, and it could be a much bigger challenge because our geological development has changed the surface significantly compared to Mars, Johnson explains.

“It is reasonable to assume that the photolysis of CO2 was also a prerequisite for the emergence of life here on Earth, in all its complexity. But we have not yet found this “smoking gun” material here on Earth to prove that the process took place. Perhaps because Earth’s surface is much more alive, geologically and literally, and therefore constantly changing. But it is a big step that we have now found it on Mars, from a time when the two planets were very similar,” says Matthew Johnson.

Facts: Organic material

The sample found on Mars contains deposits of so-called organic material. To laymen this may sound more exciting than it is. Organic material in a chemical context does not necessarily mean something living, as one might normally think. The term covers molecules that contain carbon and at least one other element and can easily exist without life. These molecules are rather the building blocks of life.

Facts: What is Photolysis

Photolysis means that the Sun’s UV rays provide molecules with energy to perform a chemical transformation. According to the research this happened in the Martian atmosphere, where 20% of CO2 molecules there were split into oxygen and carbon monoxide.

In earlier research, Johnson and colleagues showed that carbon dioxide containing the carbon-12 isotope is photolysed more quickly than the heavier isotope carbon-13.

Over time, CO is produced that is depleted in 13C, and 13C builds up in the remaining CO2. This results in so-called isotopic enrichment in CO2 and depletion in CO, like mirror images or each other or the two halves of a broken plate.

It is the fractionation ratio in carbon, which serves as evidence of photolysis in the two samples from Mars.

Facts: The oxygen painted Mars red

Photolysis of a CO2 molecule yields carbon monoxide (CO) and an oxygen atom (O). On Mars, only carbon monoxide remains, which is transformed into the organic material found by the Curiosity rover.

But where the oxygen has gone is also no secret. The oxygen combines into O2, which interacts with iron on Mars’ surface. The Red Planet is rust red due to oxidized iron.

Facts: Isotopes Have Different Weights

Isotopes are variants of the same element that have different weights because the nucleus contains more or fewer neutrons.

Carbon has two stable isotopes — Normally, about 99% of carbon has 6 protons and 6 neutrons in its nucleus (12C). About 1% has 6 protons and 7 neutrons instead (13C). The ratio can serve as a chemical fingerprint revealing what reactions the carbon has undergone.

Photolysis favors carbon-12, and a high concentration of the isotope can therefore indicate this process.

Extra Info: The Famous Mars Meteorite

The discovery of organic sediments on Mars with a low ratio of carbon-13 completes the puzzle of empirical evidence for the photolysis theory, since researchers already found the other part of that puzzle years ago in the famous meteorite, Allan Hills 84001. The meteorite contains carbonate with a heightened concentration of heavy carbon 13 isotopes.

Discovered in Antarctica 40 years ago by Roberta Score, the meteorite is believed to originate from the Red Planet and became particularly well known because it contains some deposits that led NASA researchers to announce in 1996 that they believed they had found traces of microscopic fossils of bacteria from Mars.

Today, the consensus is that these deposits are abiotic — that is, stemming from non-biological processes.

Extra info: Mars, Earth, and Venus Had the Same Atmosphere

According to researchers, Earth had approximately the same atmosphere as our neighboring planets Mars and Venus billions of years ago.

When the early planets Venus, Earth, and Mars eventually formed solid surfaces, researchers believe they began to release large amounts of CO2 from extreme volcanic activity. That’s how they formed their first atmospheres with large concentrations of the gas. Oxygen had not yet become part of the atmosphere; this happened later on Earth, after the emergence of life.

The photolysis theory states that UV rays from the sun then start a chain of chemical reactions. A chain that starts with the breakdown of CO2 into carbon monoxide, which is the building block for a multitude of other chemical compounds.

Thus, with the help of the Sun, the foundation for the many carbon compounds and complex molecules we have today was formed — in the case of Earth, the foundation for life.

“Since then the fate of the three planets has been significantly different. Earth’s carbon dioxide reacted with our large amount of surface water and much of it deposited over time as carbonate rocks like limestone, leaving the atmosphere dominated by nitrogen, as we have today. Life arose, and microorganisms produced oxygen, which, among other things, created our ozone layer, while Mars and Venus still have very CO2-dominant atmospheres today,” explains Matthew Johnson.

Today, Venus has a very dense and toxic atmosphere primarily of CO2, which gives it a surface temperature of around 450 degrees Celsius.

On Mars, the atmosphere has become much thinner compared to Earth’s, and has left a desert landscape.

Reference:

Yuichiro Ueno, Johan A. Schmidt, Matthew S. Johnson, Xiaofeng Zang, Alexis Gilbert, Hiroyuki Kurokawa, Tomohiro Usui, Shohei Aoki. Synthesis of 13C-depleted organic matter from CO in a reducing early Martian atmosphere. Nature Geoscience, 2024; 17 (6): 503 DOI: 10.1038/s41561-024-01443-z

Note: The above post is reprinted from materials provided by University of Copenhagen – Faculty of Science.

Investigating newly discovered hydrothermal vents at depths of 3,000 meters off Svalbard

Among the numerous hydrothermal mounds of the Jøtul field is the Nidhogg spring, named after a serpent-like dragon in Norse mythology that lives on the world tree Yggdrasil. The fluids with temperatures of 40 to 50 degrees Celsius at Nidhogg lead to the precipitation of barite and amorphous opal, and the numerous amphipods particularly like these temperatures. Photo: MARUM – Center for Marine Environmental Sciences, University of Bremen
Among the numerous hydrothermal mounds of the Jøtul field is the Nidhogg spring, named after a serpent-like dragon in Norse mythology that lives on the world tree Yggdrasil. The fluids with temperatures of 40 to 50 degrees Celsius at Nidhogg lead to the precipitation of barite and amorphous opal, and the numerous amphipods particularly like these temperatures. Photo: MARUM – Center for Marine Environmental Sciences, University of Bremen

Hydrothermal vents are seeps on the sea floor from which hot liquids escape. “Water penetrates into the ocean floor where it is heated by magma. The overheated water then rises back to the sea floor through cracks and fissures. On its way up the fluid become enriched in minerals and materials dissolved out of the oceanic crustal rocks. These fluids often seep out again at the sea floor through tube-like chimneys called black smokers, where metal-rich minerals are then precipitated,” explains Prof. Gerhard Bohrmann of MARUM and chief scientist of the MARIA S. MERIAN (MSM 109) expedition.

At water depths greater than 3,000 meters, the remote-controlled submersible vehicle MARUM-QUEST took samples from the newly discovered hydrothermal field.

Named after Jøtul, a giant in Nordic mythology, the field is located on the 500-kilometer-long Knipovich Ridge.

The ridge lies within the triangle formed by Greenland, Norway and Svalbard on the boundary of the North American and European tectonic plates.

This kind of plate boundary, where two plates move apart, is called a spreading ridge.

The Jøtul Field is located on an extremely slow spreading ridge with a growth rate of the plates of less than two centimeters per year.

Because very little is known about hydrothermal activity on slow spreading ridges, the expedition focused on obtaining an overview of the escaping fluids, as well as the size and composition of active and inactive smokers in the field.

“The Jøtul Field is a discovery of scientific interest not only because of its location in the ocean but also due to its climate significance, which was revealed by our detection of very high concentrations of methane in the fluid samples, among other things,” reports Gerhard Bohrmann.

Methane emissions from hydrothermal vents indicate a vigorous interaction of magma with sediments.

On its journey through the water column, a large proportion of the methane is converted into carbon dioxide, which increases the concentration of CO2 in the ocean and contributes to acidification, but it also has an impact on climate when it interacts with the atmosphere.

The amount of methane from the Jøtul Field that eventually escapes directly into the atmosphere, where it then acts as a greenhouse gas, still needs to be studied in more detail.

There is also little known about the organisms living chemosynthetically in the Jøtul Field.

In the darkness of the deep ocean, where photosynthesis cannot occur, hydrothermal fluids form the basis for chemosynthesis, which is employed by very specific organisms in symbiosis with bacteria.

In order to significantly expand on the somewhat sparse information available on the Jøtul Field, a new expedition of the MARIA S. MERIAN will start in late summer of this year under the leadership of Gerhard Bohrmann. The focus of the expedition is the exploration and sampling of as yet unknown areas of the Jøtul Field. With extensive data from the Jøtul Field it will be possible to make comparisons with the few already known hydrothermal fields in the Arctic province, such as the Aurora Field and Loki’s Castle.

Reference:

Gerhard Bohrmann, Katharina Streuff, Miriam Römer, Stig-Morten Knutsen, Daniel Smrzka, Jan Kleint, Aaron Röhler, Thomas Pape, Nils Rune Sandstå, Charlotte Kleint, Christian Hansen, Christian dos Santos Ferreira, Maren Walter, Gustavo Macedo de Paula Santos, Wolfgang Bach. Discovery of the first hydrothermal field along the 500-km-long Knipovich Ridge offshore Svalbard (the Jøtul field). Scientific Reports, 2024; 14 (1) DOI: 10.1038/s41598-024-60802-3

Note: The above post is reprinted from materials provided by MARUM – Center for Marine Environmental Sciences, University of Bremen.

Musankwa sanyatiensis, a new dinosaur from Zimbabwe

Musankwa sanyatiensis leg bones as they were discovered in the ground on Spurwing Island, Lake Kariba, Zimbabwe. Credit: Paul Barrett
Musankwa sanyatiensis leg bones as they were discovered in the ground on Spurwing Island, Lake Kariba, Zimbabwe. Credit: Paul Barrett

Fossils found on the shoreline of Lake Kariba in Zimbabwe represent a completely new dinosaur species. This remarkable find, named Musankwa sanyatiensis, marks only the fourth dinosaur species named from Zimbabwe. The research detailing this significant discovery is set to be published in the journal Acta Palaeontologica Polonica. The study was conducted by an international team of scientists from the University of the Witwatersrand (Wits) in South Africa, the Natural History Museum of Zimbabwe, Stony Brook University in New York and was led by Prof Paul Barrett from the Natural History Museum in London.

The discovery of Musankwa sanyatiensis is particularly significant as it is the first dinosaur to be named from the Mid-Zambezi Basin of northern Zimbabwe in over 50 years. Additionally, it is only the fourth dinosaur to be named from Zimbabwe, following the descriptions of “Syntarsus” rhodesiensis in 1969, Vulcanodon karibaensis in 1972, and, most recently, Mbiresaurus raathi in 2022.

The rocks yielding this new specimen date back to the Late Triassic period, approximately 210 million years ago. Musankwa sanyatiensis is represented by the remains of a single hind leg, including its thigh, shin, and ankle bones. “Despite the limited fossil material, these bones possess unique features that distinguish them from those of other dinosaurs living at the same time,” says Dr Kimberley ‘Kimi’ Chapelle, assistant professor at Stony Brook University and an honorary associate at the Evolutionary Studies Institute at Wits.

The discovery was named Musankwa sanyatiensis after the houseboat “Musankwa.” In the Tonga dialect, “Musankwa” means “boy close to marriage.” This vessel served as the research team’s home and mobile laboratory during two field expeditions to Lake Kariba in 2017 and 2018. The vessel was made available to the research team through the generosity of David and Julie Glynn, and the crew — Coster Katupu, Godfrey Swalika, Simbarashe Mangoroma, and Never Mapira — who provided essential logistic support.

Evolutionary analysis reveals that Musankwa sanyatiensis was a member of the Sauropodomorpha, a group of bipedal, long-necked dinosaurs that were widespread during the Late Triassic. Interestingly, this dinosaur appears to be closely related to contemporaries in South Africa and Argentina. Weighing in at around 390 kg, the plant-eating Musankwa sanyatiensis was one of the larger dinosaurs of its era.

Africa has a long history of dinosaur discovery, with the first dinosaur in the southern hemisphere found in South Africa just three years after the term “dinosaur” was coined by Sir Richard Owen in 1842. However, most known dinosaur fossils have been found in just 10 countries, particularly in the northern hemisphere, leading to a sparse representation of African dinosaur diversity in the global fossil record. “The main reason for the underrepresentation of African dinosaur fossils is ‘undersampling’,” says Barrett. “Put simply, there have been fewer people looking for and unearthing dinosaurs in comparison with other regions of the world,” he notes.

Despite the fewer discoveries in Africa, many of these fossils are historically and scientifically significant. These include some of the oldest dinosaurs like Nyasasaurus parringtoni from Tanzania and Mbiresaurus raathi from Zimbabwe, as well as rich dinosaur faunas from South Africa, Tanzania, Niger, and Morocco.

The Late Triassic-Early Jurassic sediments of Zimbabwe are crucial for understanding the End-Triassic extinction, a catastrophic event that dramatically reshaped Earth’s biodiversity around 200 million years ago. These different layers provide insights into how different fossil-bearing sediments around the world correspond in age and help in piecing together the global picture of prehistoric life.

This new dinosaur species also highlights the untapped potential of the region for further paleontological discoveries. Barrett elaborates: “Over the last six years, many new fossil sites have been recorded in Zimbabwe, yielding a diverse array of prehistoric animals, including the first sub-Saharan mainland African phytosaurs (ancient crocodile-like reptiles), metoposaurid amphibians (giant armoured amphibians), lungfish, and other reptile remains.”

As more fossil sites are explored and excavated, there is hope for uncovering further significant finds that will shed light on the early evolution of dinosaurs and the ecosystems they inhabited. “Based on where it sits on the dinosaur family tree, Musanwka sanyantiensis is the first dinosaur of its kind from Zimbabwe,” Dr Kimi Chapelle excitedly explains. “It, therefore, highlights the potential of the region for further palaeontological discoveries,” she says.

Reference:
Paul Barrett, Kimberley Chapelle, Lara Sciscio, Timothy Broderick, Michel Zondo, Darlington Munyikwa, Jonah Choiniere. A new sauropodomorph dinosaur from the Late Triassic of the Mid-Zambezi Basin, Zimbabwe. Acta Palaeontologica Polonica, 2024; 69 DOI: 10.4202/app.01100.2023

Note: The above post is reprinted from materials provided by University of the Witwatersrand.

Origins of ‘Welsh dragons’ finally exposed by experts

Footprint found in Triassic rocks from South Wales Credit: Cindy Howells at the National Museum of Wales
Footprint found in Triassic rocks from South Wales
Credit: Cindy Howells at the National Museum of Wales

A large fossil discovery has helped shed light on the history of dinosaurs in Wales.

Until recently, the land of the dragon didn’t have any dinosaurs. However, in the last ten years, several dinosaurs have been reported, but their life conditions were not well known. In a new study by a team from the University of Bristol and published in Proceedings of the Geologists’ Association, important details have been revealed for the first time.

They found that early Welsh dinosaurs from over 200 million year ago lived on a tropical lowland beside the sea. Dinosaur trackways are known from Barry and other sites nearby, showing that dinosaurs had walked across the warm lowlands.

The discovery was made at Lavernock Point, close to Cardiff and Penarth, where the cliffs of dark-coloured shales and limestones document ancient shallow seas. At several levels, there are accumulations of bones, including the remains of fish, sharks, marine reptiles and occasionally, dinosaurs.

Former student of the Bristol MSc in Palaeobiology Owain Evans led the study. He explained: “The bone bed paints the picture of a tropical archipelago, which was subjected to frequent storms, that washed material from around the surrounding area, both in land and out at sea, into a tidal zone. This means that from just one fossil horizon, we can reconstruct a complex ecological system, with a diverse array of marine reptiles like ichthyosaurs, plesiosaurs and placodonts in the water, and dinosaurs on land.

“I had visited the coast at Penarth all my life, growing up in Cardiff, but never noticed the fossils. Then, the more I read, the more amazing it became. Local geologists had been collecting bones since the 1870s, and most of these are in the National Museum of Wales in Cardiff.”

Cindy Howells, Curator of Palaeontology at the National Museum of Wales, adds: “The collections from Lavernock go all the way back to the 19th century, with many sections of the bone bed being collected over the years. The presence of dinosaur fossils at the site ensure that it remains one of the most significant localities for palaeontology in Wales.”

Two discoveries made by the team while conducting fieldwork at Lavernock were the fossilized remains of a placodont osteoderm, and a single coelacanth gular bone. Supervisor Dr Chris Duffin said: “The remains of coelacanths and placodonts are relatively rare in the UK, which makes these finds even more remarkable. These two fossils alone help build a broader picture of what the Rhaetian in the UK would have looked like.”

Professor Michael Benton from Bristol’s School of Earth Sciences, another project supervisor, adds: “The volume of dinosaur remains found at Lavernock is extremely exciting, and is a chance to study a complex, and often mysterious period in their evolutionary history. We have identified the remains of a large Plateosaurus like animal, along with several bones which likely belonged to a predatory theropod.”

A significant section of the paper is dedicated to the abundant microfossils found at the site, which include fish teeth, scales and bone fragments. By examining thousands of specimens, the team were able to identify the key species in the shallow seas and work out the relative importance of each.

The origins of the Welsh dragons have been pinned down at last.

Reference:
Owain Evans, Christopher J. Duffin, Claudia Hildebrandt, Michael J. Benton. Microvertebrates from the basal Rhaetian Bone Bed (Late Triassic) at Lavernock, South Wales. Proceedings of the Geologists’ Association, 2024; DOI: 10.1016/j.pgeola.2024.05.001

Note: The above post is reprinted from materials provided by University of Bristol.

Ancient polar sea reptile fossil is oldest ever found in Southern Hemisphere

Reconstruction of the oldest sea-going reptile from the Southern Hemisphere. Nothosaurs swimming along the ancient southern polar coast of what is now New Zealand around 246 million years ago. Artwork by Stavros Kundromichalis.
Reconstruction of the oldest sea-going reptile from the Southern Hemisphere. Nothosaurs swimming along the ancient southern polar coast of what is now New Zealand around 246 million years ago. Artwork by Stavros Kundromichalis.

An international team of scientists has identified the oldest fossil of a sea-going reptile from the Southern Hemisphere — a nothosaur vertebra found on New Zealand’s South Island. 246 million years ago, at the beginning of the Age of Dinosaurs, New Zealand was located on the southern polar coast of a vast super-ocean called Panthalassa.

Reptiles first invaded the seas after a catastrophic mass extinction that devastated marine ecosystems and paved the way for the dawn of the Age of Dinosaurs almost 252 million years ago. Evidence for this evolutionary milestone has only been discovered in a few places around the world: on the Arctic island of Spitsbergen, northwestern North America and southwestern China. Although represented by just a single vertebra that was excavated from a boulder in a stream bed at the foot of Mount Harper on the South Island of New Zealand — this discovery has shed new light on the previously unknown record of early sea reptiles from the Southern Hemisphere.

Reptiles ruled the seas for millions of years before dinosaurs dominated the land. The most diverse and geologically longest surviving group were the sauropterygians, with an evolutionary history spanning over 180 million years. The group included the long-necked plesiosaurs, which resembled the popular image of the Loch Ness Monster. Nothosaurs were distant predecessors of the Plesiosaurs. They could grow up to seven metres long and swam using four paddle-like limbs. Nothosaurs had flattened skulls with a meshwork of slender conical teeth that were used to catch fish and squid.

The New Zealand nothosaur was discovered during a geological survey in 1978, but its importance was not fully recognised until palaeontologists from Sweden, Norway, New Zealand, Australia and East Timor joined their expertise to examine and analyse the vertebra and other associated fossils.

“The nothosaur found in New Zealand is over 40 million years older than the previously oldest known sauropterygian fossils from the Southern Hemisphere. We show that these ancient sea reptiles lived in a shallow coastal environment teeming with marine creatures within what was then the southern polar circle,” explains Dr Benjamin Kear from The Museum of Evolution at Uppsala University, lead author on the study.

The oldest nothosaur fossils are around 248 million years old and have been found along an ancient northern low-latitude belt that stretched from the remote northeastern to northwestern margins of the Panthalassa super-ocean. The origin, distribution and timing of when nothosaurs reached these distant areas are still debated. Some theories suggest that they either migrated along northern polar coastlines, or swam through inland seaways, or used currents to cross the Panthalassa super-ocean.

The new nothosaur fossil from New Zealand has now upended these long-standing hypotheses.

“Using a time-calibrated evolutionary model of sauropterygian global distributions, we show that nothosaurs originated near the equator, then rapidly spread both northwards and southwards at the same time as complex marine ecosystems became re-established after the cataclysmic mass extinction that marked the beginning of the Age of Dinosaurs” says Kear.

“The beginning of the Age of Dinosaurs was characterised by extreme global warming, which allowed these marine reptiles to thrive at the South Pole. This also suggests that the ancient polar regions were a likely route for their earliest global migrations, much like the epic trans-oceanic journeys undertaken by whales today. Undoubtedly, there are more fossil remains of long-extinct sea monsters waiting to be discovered in New Zealand and elsewhere in the Southern Hemisphere,” says Kear.

The New Zealand nothosaur fossil is held in the National Palaeontological Collection at GNS Science in New Zealand.

Reference:
Benjamin P. Kear, Aubrey J. Roberts, George Young, Marianna Terezow, Daniel J. Mantle, Isaias Santos Barros, Jørn H. Hurum. Oldest southern sauropterygian reveals early marine reptile globalization. Current Biology, 2024; 34 (12): R562 DOI: 10.1016/j.cub.2024.03.035

Note: The above post is reprinted from materials provided by Uppsala University.

Iceland’s volcano eruptions may last decades

The progression of the 2021 Fagradalsfjall eruption.
The progression of the 2021 Fagradalsfjall eruption.

Scientists predict from geochemical data that Iceland is entering a new volcanic era that will last for decades, possibly centuries. Under an hour’s drive from the country’s capital city, the ongoing eruptions pose considerable risks for economic disruption, and they leave evacuated communities uncertain of a possible return.

Iceland’s ongoing volcanic eruptions may continue on and off for years to decades, threatening the country’s most densely populated region and vital infrastructure, researchers predict from local earthquake and geochemical data.

The eruptions on the Reykjanes Peninsula have forced authorities to declare a state of emergency, with a series of eight eruptions having occurred since 2021. This southwestern region is home to 70 percent of the country’s population, its only international airport, and several geothermal power plants that supply hot water and electricity. The most recent eruption in May through June triggered the evacuation of residents and visitors of the Blue Lagoon geothermal spa, a popular tourist attraction, for the third time in more than two months.

Although Iceland sees regular eruptions because it sits above a volcanic hot spot, the Reykjanes Peninsula has been dormant for 800 years. Its last volcanic era continued over centuries however, prompting scientists to predict the renewed volcanism to be the start of a long episode.

Under an hour’s drive from the island’s capital city Reykjavík, the eruptions pose considerable risks for economic disruption, and they leave evacuated communities uncertain of a possible return.

An international team of scientists has been watching the volcanoes over the past three years. Analyzing seismic tomography imaging and the composition of lava samples, they’ve uncovered parts of the geological processes behind the new volcanic era. They predict the region may have to prepare for recurring eruptions lasting years to decades and possibly centuries.

The researchers report their findings in a paper published June 26 in the journal Terra Nova. The project included collaborations from the University of Oregon, Uppsala University in Sweden, University of Iceland, Czech Academy of Sciences and University of California, San Diego. The work follows an earlier Nature Communications study of the initial Reykjanes eruptions in 2021.

Almost all of Iceland’s island is built from lava, said Ilya Bindeman, a volcanologist and earth sciences professor at the UO. The country sits on the Mid-Atlantic Ridge, the tectonic plate boundary that causes North America and Eurasia to push further apart. The drifting of these plates can spark volcanic eruptions when hot rock from the earth’s mantle — the middle and largest layer of the planet — melts and rises to the surface.

Although scientists know the origin of Reykjanes Peninsula’s current eruptions is plate movement, the kind of magma storage and plumbing systems that feed them are unidentified, Bindeman said. The peninsula consists of eight volcanically active sites, so understanding whether there is one shared magma source or multiple independent ones and their depth can help predict the duration and impact of these eruptions.

Using geochemical and seismic data, the researchers investigated whether the magma of the initial eruptions from one volcano in the peninsula from 2021 to 2023 came from the same source as the magma in the recent eruptions of a different volcano to the west.

Bindeman specializes in isotopic analysis, which can help identify the “fingerprint” of magma. Magma is made of mostly eight elements, including oxygen and hydrogen, and 50 different trace elements in smaller concentrations and various ratios. The unique combination of trace elements can help differentiate magma sources from one another. Scientists can also measure the abundance of isotopes, elements with the same chemical property but different masses, in the magma. There are three different isotopes of oxygen, for example, Bindeman said.

“In the air we breathe, there’s a mixture of these oxygen isotopes and we don’t feel the difference,” he said. “Their differences are usually not important for chemical reactions but are important to recognize as their relative abundances in magma can differentiate one magma source from another.”

Analyzing samples of lava rock from two different volcanoes in the peninsula, their similar fingerprints implied a shared magma storage zone below the peninsula. Imaging of earth’s interior based on local earthquakes also suggested the existence of a reservoir about 5.5 to 7.5 miles in the earth’s crust, the shallowest layer.

However, that storage is ultimately fed by the melting rock deeper in the mantle, which can cause eruptions that last decades, with hundreds of square miles of magma surfacing, Bindeman said. Iceland’s hotspot also will have no problem fountaining that flow, he said.

Although this marks the beginning of potentially persistent volcanic episodes in Iceland, the researchers can’t precisely predict yet how long the episodes and the gaps between each will last.

“Nature is never regular,” Bindeman said. “We don’t know how long and how frequently it will continue for the next ten or even hundred years. A pattern will emerge, but nature always has exceptions and irregularities.”

Discussions are continuing on plans to safely drill into the volcanic sites to glean insights into the geological processes driving the eruptions.

Because the volcanic activity is less volatile and explosive than eruptions in other countries, it provides a rare opportunity for scientists to approach fissures actively erupting lava, Bindeman said. He called it a “natural laboratory” both astonishing and chilling.

“When you witness a volcanic eruption, you can feel that these are the massive forces of nature, and you yourself are very small,” Bindeman said. “These events are ordinary from the geological scale, but from the human scale, they can be devastating.”

Reference:
Valentin R. Troll, Frances M. Deegan, Thor Thordarson, Ari Tryggvason, Lukáš Krmíček, William M. Moreland, Björn Lund, Ilya N. Bindeman, Ármann Höskuldsson, James M. D. Day. The Fagradalsfjall and Sundhnúkur Fires of 2021–2024: A single magma reservoir under the Reykjanes Peninsula, Iceland? Terra Nova, 2024; DOI: 10.1111/ter.12733

Note: The above post is reprinted from materials provided by University of Oregon. Original written by Leila Okahata.

The rotation of Earth’s inner core has slowed, new study confirms

inner core (USC Graphic/Edward Sotelo)
inner core (USC Graphic/Edward Sotelo)

USC scientists have proven that the Earth’s inner core is backtracking — slowing down — in relation to the planet’s surface, as shown in new research published Wednesday in Nature.

Movement of the inner core has been debated by the scientific community for two decades, with some research indicating that the inner core rotates faster than the planet’s surface. The new USC study provides unambiguous evidence that the inner core began to decrease its speed around 2010, moving slower than the Earth’s surface.

“When I first saw the seismograms that hinted at this change, I was stumped,” said John Vidale, Dean’s Professor of Earth Sciences at the USC Dornsife College of Letters, Arts and Sciences. “But when we found two dozen more observations signaling the same pattern, the result was inescapable. The inner core had slowed down for the first time in many decades. Other scientists have recently argued for similar and different models, but our latest study provides the most convincing resolution.”

The relativity of backtracking and slowing down

The inner core is considered to be reversing and backtracking relative to the planet’s surface due to moving slightly slower instead of faster than the Earth’s mantle for the first time in approximately 40 years. Relative to its speed in previous decades, the inner core is slowing down.

The inner core is a solid iron-nickel sphere surrounded by the liquid iron-nickel outer core. Roughly the size of the moon, the inner core sits more than 3,000 miles under our feet and presents a challenge to researchers: It can’t be visited or viewed. Scientists must use the seismic waves of earthquakes to create renderings of the inner core’s movement.

A new take on a repetitive approach

Vidale and Wei Wang of the Chinese Academy of Sciences utilized waveforms and repeating earthquakes in contrast to other research. Repeating earthquakes are seismic events that occur at the same location to produce identical seismograms.

In this study, the researchers compiled and analyzed seismic data recorded around the South Sandwich Islands from 121 repeating earthquakes that occurred between 1991 and 2023. They have also utilized data from twin Soviet nuclear tests between 1971 and 1974, as well as repeated French and American nuclear tests from other studies of the inner core.

Vidale said the inner core’s slowing speed was caused by the churning of the liquid iron outer core that surrounds it, which generates Earth’s magnetic field, as well as gravitational tugs from the dense regions of the overlying rocky mantle.

The impact on the Earth’s surface

The implications of this change in the inner core’s movement for Earth’s surface can only be speculated. Vidale said the backtracking of the inner core may alter the length of a day by fractions of a second: “It’s very hard to notice, on the order of a thousandth of a second, almost lost in the noise of the churning oceans and atmosphere.”

The USC scientists’ future research aspires to chart the trajectory of the inner core in even greater detail to reveal exactly why it is shifting.

“The dance of the inner core might be even more lively than we know so far,” Vidale said.

This research was supported by the National Science Foundation (EAR-2041892) and the Institute of Geology and Geophysics of the Chinese Academy of Sciences (IGGCAS-201904 and IGGCAS-202204).

Reference:
Wei Wang, John E. Vidale, Guanning Pang, Keith D. Koper, Ruoyan Wang. Inner core backtracking by seismic waveform change reversals. Nature, 2024; DOI: 10.1038/s41586-024-07536-4

Note: The above post is reprinted from materials provided by University of Southern California.

Laser tests reveal new insights into key mineral for super-Earths

JPL / NASA
JPL / NASA

Scientists have for the first time observed how atoms in magnesium oxide morph and melt under ultra-harsh conditions, providing new insights into this key mineral within Earth’s mantle that is known to influence planet formation.

High-energy laser experiments — which subjected tiny crystals of the mineral to the type of heat and pressure found deep inside a rocky planet’s mantle — suggest the compound could be the earliest mineral to solidify out of magma oceans in forming “super-Earth” exoplanets.

“Magnesium oxide could be the most important solid controlling the thermodynamics of young super-Earths,” said June Wicks, an assistant professor of Earth and Planetary Sciences at Johns Hopkins University who led the research. “If it has this very high melting temperature, it would be the first solid to crystallize when a hot, rocky planet starts to cool down and its interior separates into a core and a mantle.”

The findings are newly published in Science Advances.

They suggest that the way magnesium oxide transitions from one form to another could have important implications for the factors that control whether a young planet will be a snowball or a molten rock, develop water oceans or atmospheres, or have a mixture of those features.

“In terrestrial super-Earths, where this material is going to be a big component of the mantle, its transformation is going to contribute significantly to how quickly heat moves in the interior, which is going to control how the interior and the rest of the planet form and deform over time,” Wicks said. “We can think of this as a proxy for interiors of these planets, because it’s going to be the material that controls its deformation, one of the most important building blocks of rocky planets.”

Larger than Earth but smaller than giants like Neptune or Uranus, super-Earths are key targets in exoplanet searches because they are commonly found among other solar systems in the galaxy. While the composition of these planets can vary from gas to ice or water, rocky super-Earths are expected to contain significant amounts of magnesium oxide that can influence the planet’s magnetic field, volcanism, and other key geophysics like they do on Earth, Wicks said.

To mimic the extreme conditions this mineral might sustain during planet formation, Wick’s team subjected small samples to ultra-high pressures using the Omega-EP laser facility at the University of Rochester’s Laboratory for Laser Energetics. The scientists also shot X-rays and recorded how those light rays bounced off the crystals to track how their atoms rearranged in response to the increasing pressures, specifically noting at what point they transformed from a solid to a liquid.

When squeezed extremely hard, the atoms of materials like magnesium oxide change their arrangement to sustain the crushing pressures. That’s why the mineral transitions from a rock salt “phase” resembling table salt to a different configuration like that of another salt called cesium chloride as pressure increases. This makes for a transformation that can affect a mineral’s viscosity and impact on a planet as it comes of age, Wicks said.

The team’s results show that magnesium oxide can exist in both of its phases at pressures ranging from 430 to 500 gigapascals and temperatures of around 9,700 Kelvin, nearly twice as hot as the surface of the sun. The experiments also show that the highest pressures the mineral can withstand before melting completely are upward of 600 gigapascals, about 600 times the pressure one would feel in the deepest trenches of the ocean.

“Magnesium oxide melts at a much higher temperature than any other material or mineral. Diamonds may be the hardest materials, but this is what will melt last,” Wicks said. “When it comes to extreme materials in young planets, magnesium oxide is likely going to be solid, whereas everything else that will be hanging out down there in the mantle is going to be turned to liquid.”

The study showcases the stability and simplicity of magnesium oxide under extreme pressures and could help scientists develop more accurate theoretical models to probe key questions about the behavior of this and other minerals within rocky worlds like Earth, Wicks said.

“The study is a love letter to magnesium oxide, because it’s amazing that it has the highest temperature melting point that we know of — at pressures beyond the center of Earth — and it still behaves like a regular salt,” Wicks said. “It’s just a beautiful, simple salt, even at these record pressures and temperatures.”

Other authors are Saransh Singh, Marius Millot, Dayne E. Fratanduono, Federica Coppari, Martin G. Gorman, Jon H. Eggert, and Raymond F. Smith of Lawrence Livermore National Laboratory; Zixuan Ye and Anirudh Hari of Johns Hopkins University; J. Ryan Rygg of the University of Rochester; and Thomas S. Duffy of Princeton University.

This research was supported by NNSA through the National Laser Users’ Facility Program under contract Nos. DE-NA0002154 and DE-NA0002720 and the Laboratory Directed Research and Development Program at LLNL (project No. 15-ERD-012). This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract No. DE-AC52-07NA27344. The research was supported by National Nuclear Security Administration through the National Laser Users’ Facility Program (contract Nos. DE-NA0002154 and DE-NA0002720) and the Laboratory Directed Research and Development Program at LLNL (project Nos. 15-ERD-014, 17-ERD-014, and 20-ERD-044).

Reference:
June K. Wicks, Saransh Singh, Marius Millot, Dayne E. Fratanduono, Federica Coppari, Martin G. Gorman, Zixuan Ye, J. Ryan Rygg, Anirudh Hari, Jon H. Eggert, Thomas S. Duffy, Raymond F. Smith. B1-B2 transition in shock-compressed MgO. Science Advances, 2024; 10 (23) DOI: 10.1126/sciadv.adk0306

Note: The above post is reprinted from materials provided by Johns Hopkins University. Original written by Roberto Molar Candanosa.

A mountainous mystery uncovered in Australia’s pink sands

Garnet washed up as pink sand on a beach in Dhilba Guuranda-Innes National Park. Photo credit: University of Adelaide.
Garnet washed up as pink sand on a beach in Dhilba Guuranda-Innes National Park. Photo credit: University of Adelaide.

Deposits of deep-pink sand washing up on South Australian shores shed new light on when the Australian tectonic plate began to subduct beneath the Pacific plate, as well as the presence of previously unknown ancient Antarctic mountains.

The pink sand is composed of a mineral called garnet, and a University of Adelaide research team, led by PhD candidate Sharmaine Verhaert and Associate Professor Stijn Glorie, used a new, cutting-edge method to show the garnet grains are around 590 million years old.

Garnet is known to have formed locally during the Delamerian orogeny, an event which created the Adelaide Fold Belt around 514-490 million years ago, and during the formation of the Gawler Craton in western South Australia between 3.3-1.4 billion years ago. These ages don’t match the garnet sand on South Australian shores.

“The garnet is too young to have come from the Gawler Craton and too old to have come from the eroding Adelaide Fold Belt,” says Verhaert.

“Garnet requires high temperatures to form and is usually associated with the formation of large mountain belts, and this was a time when the South Australian crust was comparatively cool and non-mountainous.”

The researchers, who published their findings in the journal Communications Earth & Environment, established the garnet does not originate from local source rocks, but they knew it had travelled from nearby as garnet is typically destroyed through prolonged exposure to the marine environment.

They discovered that the glacial sedimentary deposits of the Cape Jervis Formation, cropping out along the South Australian shorelines, contain layers of sand with garnet that is also around 590 million years old.

Ice-flow indicators in these glacial sedimentary deposits tell us that the garnet-rich glacial sands were brought to Australia by a north-west moving ice sheet during the Late Palaeozoic Ice Age, when Australia and Antarctica were connected in supercontinent Gondwana.

Garnet dating to the same period has been found previously in an outcrop in the Transantarctic Mountains in East Antarctica, at the edge of a colossal area that is completely concealed by a thick ice sheet. Researchers believe this area hosts evidence of a 590-million-year-old mountain belt hiding below the Antarctic ice.

“While it is currently not possible to sample directly under this ice sheet, it is conceivable that millions of years of ice transport eroded the bedrock underneath and transported this cargo of garnet north-westwards, towards the conjugate Antarctic-Australian margin,” says Associate Professor Glorie.

“The garnet deposits were then locally stored in glacial sedimentary deposits along the southern Australian margin until erosion liberated them and the waves and tides concentrated them on the South Australian beaches.

“We have effectively uncovered a major mountain building event that redefines the timing of the onset of convergence in the Pacific Ocean.”

The new University of Adelaide-developed approach to lutetium-hafnium dating, which uses a laser system attached to a mass-spectrometer, allowed this momentous discovery to be made from a simple enquiry.

“This journey started with questioning why there was so much garnet on the beach at Petrel Cove,” says Dr Jacob Mulder, who was also in the research team.

“It is fascinating to think we were able to trace tiny grains of sand on a beach in Australia to a previously undiscovered mountain belt under the Antarctic ice.”

Reference:
Sharmaine Verhaert, Stijn Glorie, Martin Hand, Jacob A. Mulder, Anthony R. Milnes, Jacqueline A. Halpin. An Ediacaran orogeny in subglacial East Antarctica is uncovered by detrital garnet geochronology. Communications Earth & Environment, 2024; 5 (1) DOI: 10.1038/s43247-024-01467-8

Note: The above post is reprinted from materials provided by University of Adelaide. Original written by Johnny von Einem.

Cascadia Subduction Zone, one of Earth’s top hazards, comes into sharper focus

A schematic cross section of the Cascadia Subduction Zone shows the ocean floor plate (light grey) moving under the North American continental plate, along with other features. (Courtesy USGS)
A schematic cross section of the Cascadia Subduction Zone shows the ocean floor plate (light grey) moving under the North American continental plate, along with other features. (Courtesy USGS)

A new study has produced the first comprehensive survey of the many complex structures beneath the seafloor in the Cascadia Subduction Zone, off British Columbia, Washington, Oregon and California. It is providing scientists with key insights into how future disasters may unfold.

Off the coasts of southern British Columbia, Washington, Oregon and northern California lies a 600 mile-long strip where the Pacific Ocean floor is slowly diving eastward under North America. This area, called the Cascadia Subduction Zone, hosts a megathrust fault, a place where tectonic plates move against each other in a highly dangerous way. The plates can periodically lock up and build stress over wide areas — eventually to be released when they finally lurch against each other. The result: the world’s greatest earthquakes, shaking both seabed and land, and generating tsunamis 100 feet high or more. Such a fault off Japan caused the 2011 Fukushima nuclear disaster. Similar zones exist off Alaska, Chile and New Zealand, among other places. At Cascadia, big quakes are believed to come roughly every 500 years, give or take a couple hundred. The last occurred in 1700.

Scientists have long been working to understand the Cascadia Subduction Zone’s subterranean structures and mechanics, in order to delineate places most susceptible to quakes, how big they might be and what warning signs they might produce. There is no such thing as predicting an earthquake; rather, scientists try to forecast probabilities of multiple scenarios, hoping to help authorities design building codes and warning systems to minimize the damage when something happens.

A newly published study promises to greatly advance this effort. A research vessel towing an array of the latest geophysical instruments along almost the entire zone has produced the first comprehensive survey of the many complex structures beneath the seafloor. These include the geometry of the down-going ocean plate and overlying sediments, and the makeup of the overriding North American plate. The study was just published in the journal Science Advances.

“The models currently in use by public agencies were based on a limited set of old, low-quality 1980s-era data,” said Suzanne Carbotte, a marine geophysicist at Columbia University’s Lamont-Doherty Earth Observatory, who led the research. “The megathrust has a much more complex geometry than previously assumed. The study provides a new framework for earthquake and tsunami hazard assessment.”

With funding from the U.S. National Science Foundation, the data was gathered during a 41-day cruise in 2021 by Lamont’s research vessel, the Marcus G. Langseth. Researchers aboard the ship penetrated the seafloor with powerful sound pulses and read the echoes, which were then converted into images, somewhat similar to how physicians create interior scans of the human body.

One key finding: the megathrust fault zone is not just one continuous structure, but is divided into at least four segments, each potentially somewhat insulated against movements of the others. Scientists have long debated whether past events, including the 1700 quake, ruptured the entire zone or just part of it — a key question, because the longer the rupture, the bigger the quake.

The data show that the segments are divided by buried features including big faults, where opposing sides slide against each other perpendicular to the shore. This might help buffer against movement on one segment translating to the next. “We can’t say that this definitely means only single segments will rupture, or that definitely the whole thing will go at once,” said Harold Tobin, a geophysicist at the University of Washington and coauthor of the study. “But this does upgrade evidence that there are segmented ruptures.”

The imagery also suggests the causes of the segmentation: the rigid edge of the overriding North American continental plate is composed of many different kinds of rocks, formed at different times over many tens of millions of years, with some being denser than others. This variety in the continental rocks causes the incoming, more pliable oceanic plate to bend and twist to accommodate differences in overlying pressure. In some places, segments go down at relatively steep angles, in others at shallow ones.

The researchers zeroed in on one segment in particular, which runs from southern Vancouver Island alongside Washington state, more or less ending at the Oregon border. The subterranean topography of other segments is relatively rough, with oceanic features like faults and subducted seamounts rubbing up against the upper plate — features that might erode the upper plate and limit how far any quake may propagate within the segment, thus limiting the quake’s size. In contrast, the Vancouver Island to south alongside Washington State segment is quite smooth. This means that it may be more likely to rupture along its entire length at once, making it potentially the most dangerous section.

Also in this segment, the seafloor is subducting under the continental crust at a shallow angle relative to the other segments. In the other segments, most of the earthquake-prone interface between the plates lies offshore, but here the study found the shallow subduction angle means it probably extends directly under Washington’s Olympic Peninsula. This might magnify any shaking on land. “It requires a lot more study, but for places like Tacoma and Seattle, it could mean the difference between alarming and catastrophic,” said Tobin.

With funding from the U.S. Geological Survey, a consortium of state and federal agencies and academic institutions has already been poring over the data since it became available to sort through the implications.

As for tsunami hazard, that is “still a work in progress,” said Kelin Wang, a research scientist at the Geological Survey of Canada who was not involved in the study. Wang’s group is using the data to model features of the seafloor off Vancouver Island that might generate tsunamis. (In general, a tsunami occurs when the deep seafloor moves up or down during a quake, sending a wave to the surface that concentrates its energy and gathers height as it reaches shallower coastal waters.) Wang said his results will go to another group that models tsunamis themselves, and after that to another group that analyzes the hazards on land.

Practical assessments that could affect building codes or other aspects of preparedness may be published as early as next year, say the researchers. “There’s a whole lot more complexity here than was previously inferred,” said Carbotte.

Reference:
Suzanne M. Carbotte, Brian Boston, Shuoshuo Han, Brandon Shuck, Jeffrey Beeson, J. Pablo Canales, Harold Tobin, Nathan Miller, Mladen Nedimovic, Anne Tréhu, Michelle Lee, Madelaine Lucas, Hanchao Jian, Danqi Jiang, Liam Moser, Chris Anderson, Darren Judd, Jaime Fernandez, Chuck Campbell, Antara Goswami, Rajendra Gahlawat. Subducting plate structure and megathrust morphology from deep seismic imaging linked to earthquake rupture segmentation at Cascadia. Science Advances, 2024; 10 (23) DOI: 10.1126/sciadv.adl3198

Note: The above post is reprinted from materials provided by Columbia Climate School. Original written by Kevin Krajick.

Fresh findings: Earliest evidence of life-bringing freshwater on Earth

The quantitative model used in the study explains the enigmatic melt degrees and layered structures observed in most cratons on Earth.
Earth.

New Curtin-led research has found evidence that fresh water on Earth, which is essential for life, appeared about four billion years ago — five hundred million years earlier than previously thought.

Lead author Dr Hamed Gamaleldien, Adjunct Research Fellow in Curtin’s School of Earth and Planetary Sciences and an Assistant Professor at Khalifa University, UAE, said by analysing ancient crystals from the Jack Hills in Western Australia’s Mid West region, researchers have pushed back the timeline for the emergence of fresh water to just a few hundred million years after the planet’s formation.

“We were able to date the origins of the hydrological cycle, which is the continuous process through which water moves around Earth and is crucial for sustaining ecosystems and supporting life on our planet,” Dr Gamaleldien said.

“By examining the age and oxygen isotopes in tiny crystals of the mineral zircon, we found unusually light isotopic signatures as far back as four billion years ago. Such light oxygen isotopes are typically the result of hot, fresh water altering rocks several kilometres below Earth’s surface.

“Evidence of fresh water this deep inside Earth challenges the existing theory that Earth was completely covered by ocean four billion years ago.”

Study co-author Dr Hugo Olierook, from Curtin University’s School of Earth and Planetary Sciences, said the discovery was crucial for understanding how Earth formed and how life emerged.

“This discovery not only sheds light on Earth’s early history but also suggests landmasses and fresh water set the stage for life to flourish within a relatively short time frame — less than 600 million years after the planet formed,” Dr Olierook said.

“The findings mark a significant step forward in our understanding of Earth’s early history and open doors for further exploration into the origins of life.”

The authors are part of the Earth Dynamics Research Group and the Timescales of Mineral Systems Group, which sit within Curtin’s School of Earth and Planetary Sciences, and the John de Laeter Centre.

Part of the research was done using the CAMECA 1300HR3 instrument in the John de Laeter Centre’s Large Geometry Ion Microprobe (LGIM) facility, which was funded by AuScope (via the Commonwealth National Collaborative Research Infrastructure Strategy), the Geological Survey of Western Australia and Curtin University.

Reference:
Hamed Gamaleldien, Li-Guang Wu, Hugo K. H. Olierook, Christopher L. Kirkland, Uwe Kirscher, Zheng-Xiang Li, Tim E. Johnson, Sean Makin, Qiu-Li Li, Qiang Jiang, Simon A. Wilde, Xian-Hua Li. Onset of the Earth’s hydrological cycle four billion years ago or earlier. Nature Geoscience, 2024; DOI: 10.1038/s41561-024-01450-0

Note: The above post is reprinted from materials provided by Curtin University. Original written by Lucien Wilkinson.

A cracking discovery – eggshell waste can recover rare earth elements needed for green energy

Composite image using high-resolution microscopy and spectroscopy showing the absorption and replacement processes of rare earth elements in the eggshell.
Composite image using high-resolution microscopy and spectroscopy showing the absorption and replacement processes of rare earth elements in the eggshell.

A collaborative team of researchers has made a cracking discovery with the potential to make a significant impact in the sustainable recovery of rare earth elements (REEs), which are in increasing demand for use in green energy technologies. The team found that humble eggshell waste could recover REES from water, offering a new, environmentally friendly method for their extraction.

The researchers, from Trinity College Dublin’s School of Natural Sciences, and iCRAG, the Science Foundation Ireland research centre in applied geosciences, have just published their ground-breaking findings in the international journal ACS Omega.

REEs, which are essential for the technologies used in electric cars and wind turbines, for example, are in increasing demand but in relatively short supply. As a result, scientists must find new ways of extracting them from the environment — and in sustainable ways, with current methods often harmful.

Here, the researchers discovered that calcium carbonate (calcite) in eggshells can effectively absorb and separate these valuable REEs from water.

The researchers placed eggshells in solutions containing REEs at various temperatures from a pleasant 25 °C to a scorching 205 °C, and for different time periods of up to three months. They found that the elements could enter the eggshells via diffusion along the calcite boundaries and the organic matrix, and, at higher temperatures, that the rare earth built new minerals on the eggshell surface.

At 90 °C, the eggshell surface helped recover formations of a rare earth compound called kozoite. As things got hotter, the eggshells underwent a complete transformation with the calcite shells dissolving and being replaced by polycrystalline kozoite. And at the highest temperature of 205°C, this mineral gradually transitioned into bastnasite, the stable rare earth carbonate mineral that is used by industry to extract REEs for technology applications.

This innovative method suggests that waste eggshells could be repurposed as a low-cost, eco-friendly material to help meet the growing demand for REES, as the eggshells trap distinct rare earths within their structure over time.

Lead author Dr Remi Rateau commented on the significance of the research, stating, “This study presents a potential innovative use of waste material that not only offers a sustainable solution to the problem of rare earth element recovery but also aligns with the principles of circular economy and waste valorisation.”

Principal Investigator, Prof. Juan Diego Rodriguez-Blanco, emphasised the broader implications of the findings, adding: “By transforming eggshell waste into a valuable resource for rare earth recovery, we address critical environmental concerns associated with traditional extraction methods and contribute to the development of greener technologies.”

Work was conducted at the Department of Geology in the School of Natural Sciences, Trinity. iCRAG (Irish Centre for Research in Applied Geosciences) is an SFI centre dedicated to advancing geosciences research with a focus on sustainable resource management and environmental protection.

Reference:
Rémi Rateau, Melanie Maddin, Adrienn M. Szucs, Luca Terribili, Kerstin Drost, Paul C. Guyett, Juan Diego Rodriguez-Blanco. Utilization of Eggshell Waste Calcite as a Sorbent for Rare Earth Element Recovery. ACS Omega, 2024; DOI: 10.1021/acsomega.4c00931

Note: The above post is reprinted from materials provided by Trinity College Dublin.

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