It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Saturday, June 28, 2025
Hadean-age rocks preserved in the Nuvvuagittuq Greenstone Belt, Canada
Summary author: Walter Beckwith
American Association for the Advancement of Science (AAAS)
The Nuvvuagittuq Greenstone Belt (NGB) – a complex geological sequence in northeastern Canada – harbors surviving fragments of Earth’s oldest crust, dating back to ~4.16 billion years old, according to a new study. The preservation of Hadean rocks on Earth’s surface could provide valuable insights into the planet’s earliest times. Much about Earth’s earliest geologic history remains poorly understood due to the rarity of Hadean-age (>4.03 billion-year-old) rocks and minerals. These ancient materials are typically altered or destroyed as the planet’s crust is recycled through ongoing tectonic processes. One candidate for surviving Hadean-age crustal rock is the NGB, which contains rock argued to be as old as 4.3 billion years. However, this claim is controversial; some argue that the isotopic data underpinning these estimates may instead reflect later geological mixing processes rather than the true age of the formation. If shown to be Hadean in origin, the NGB would represent the oldest preserved rock sequence on Earth. It would offer critical insights into early Earth geology, including the potential setting for the emergence of life.
To constrain the age of the NGB, Christian Sole and colleagues focused on a specific type of ancient rocks – metagabbroic intrusions – within the belt. According to the authors, these intrusions intersect older basaltic rocks, and this feature allowed the authors to use combined uranium-lead (U-Pb) dating with both short- and long-lived neodymium (Sm-Nd) isotopic analyses to determine a lower age limit on the more ancient formations (the older basaltic rocks). Sole et al. report that the Sm-Nd data yielded consistent isochron ages around 4.16 billion years, regardless of sample location or mineral composition. The fact that both isotopic systems yield the same age in rocks linked by clear evidence of magmatic differentiation strongly supports their Hadean-age crystallization. This, in turn, supports the idea that fragments of mafic crust from the Hadean Eon have survived in the NGB.
A team of Canadian and French researchers has confirmed that northern Quebec is home to the oldest known rocks on Earth, dating back 4.16 billion years.
Under the leadership of Jonathan O’Neil, an associate professor in the Department of Earth and Environmental Sciences at the University of Ottawa, this major discovery is the fruit of a collaboration involving Christian Sole (who completed a master’s at the University of Ottawa in 2021), Hanika Rizo, (a professor at Carleton University), Jean-Louis Paquette (a now-deceased researcher at France’s Centre national de la recherche scientifique (CNRS) in the Université Clermont-Auvergne’s Laboratoire Magmas et Volcans), David Benn (a former bachelor’s student at uOttawa) and Joeli Plakholm (a former bachelor’s student at Carleton University).
O’Neil, who supervised the original study, explains: “The results obtained during Christian Sole’s master’s were very promising. We continued the research after he completed his master’s to confirm the exceptional age of these rocks.”
An exceptional geological site
Samples were collected in 2017 near the municipality of Inukjuak, Nunavik, as part of Sole’s master’s. After preliminary analysis, additional work was carried out at the University of Ottawa and Carleton University, to confirm the age of the rocks.
“For over 15 years, the scientific community has debated the age of volcanic rocks from northern Quebec. Our previous research suggested that they could date back 4.3 billion years, but this wasn’t the consensus,” O’Neil recalls.
A window onto primitive Earth
The current study shows that the intrusive rocks crossing these volcanic formations are 4.16 billion years old, which confirms that the volcanic rocks must be older, and thus, that this region of the Canadian north is indeed home to the oldest known rocks on Earth. “This confirmation positions the Nuvvuagittuq Belt as the only place on Earth where we find rocks formed during the Hadean eon, that is, the first 500 million years of our planet’s history,” says O’Neil.
To establish the age of these rocks, the researchers combined petrology and geochemistry and applied two radiometric dating methods using different isotopes of the elements samarium and neodymium as two separate chronometers indicating the same age, 4.16 million years. This discovery opens a unique window on the early Earth. “Understanding these rocks is going back to the very origins of our planet. This allows us to better understand how the first continents were formed and to reconstruct the environment from which life could have emerged,” says O’Neil.
Scientists at the Royal Botanic Gardens, Kew and Queen Mary University of London have discovered that a new generation of ash trees, growing naturally in woodland, exhibits greater resistance to the disease compared to older trees. They find that natural selection is acting upon thousands of locations within the ash tree DNA, driving the evolution of resistance. The study, published in Science, offers renewed hope for the future of ash trees in the British landscape and provides compelling evidence for a long-standing prediction of Darwinian theory.
Ash dieback, caused by the fungus Hymenoscyphus fraxineus, arrived in Britain in 2012, prompting an emergency COBRA meeting. The disease has since wrought havoc on the British countryside, leaving behind skeletal remains of dying ash trees. Past predictions estimate that up to 85% of ash trees will succumb to the disease, with none displaying complete immunity.
The new study compared the DNA of ash trees established before and after the fungal invasion. Researchers observed subtle shifts in the frequencies of DNA variants associated with tree health across thousands of locations in the genome. These shifts indicate that the younger generation possesses greater resistance than their predecessors, offering hope for the survival of ash trees.
This research provides a real-world example of natural selection in action, as theorised by Charles Darwin. It also demonstrates selection on a trait influenced by numerous genes, a phenomenon that has been widely assumed but difficult to prove.
Professor Richard Nichols, Professor of Evolutionary Genetics at Queen Mary University of London, commented: "A tragedy for the trees has been a revelation for scientists: allowing us to show that thousands of genes are contributing to the ash trees’ fightback against the fungus. Our detection of so many small genetic effects was possible because of the exceptional combination of circumstances: the sudden arrival of such a severe disease and the hundreds of offspring produced by a mature tree."
Dr Carey Metheringham, whose PhD research included this study, commented: “Thanks to natural selection, future generations of ash should have a better chance of withstanding infection. However, natural selection alone may not be enough to produce fully resistant trees. The existing genetic variation in the ash population may be too low, and as the trees become scarcer, the rate of selection could slow. Human intervention, such as selective breeding and the protection of young trees from deer grazing, may be required to accelerate evolutionary change.”
Professor Richard Buggs, Senior Research Leader (Plant health and adaptation) at the Royal Botanic Gardens Kew, and Professor of Evolutionary Genomics at Queen Mary University of London, commented: “We are so glad that these findings suggest that ash will not go the way of the elm in Britain. Elm trees have struggled to evolve to Dutch elm disease, but ash are showing a very different dynamic because they produce an abundance of seedlings upon which natural selection can act when they are still young. Through the death of millions of ash trees, a more resistant population of ash is appearing.”
Buggs added: “Lots of textbooks about evolution have hypothetical examples of natural selection driving change in quantitative traits (for example, size and speed of wolves) but these are actually hard to prove in real life cases. Here, we provide a real example which is characterised at the DNA level.”
The study, which was mainly funded by the Department for Environment Food and Rural Affairs (Defra), was carried out in Marden Park wood in Surrey, which is owned and managed by the Woodland Trust. Rebecca Gosling, Lead Policy Advocate (Tree Health and Invasive Species) at the Woodland Trust said: “Ash dieback demonstrates how devastating introduced pathogens can be for our trees and the species which rely upon them. This important research gives us hope for the future of our ash populations. The findings highlight how vital it is to support natural regeneration in woodlands, furthering our understanding of how to best manage our ash woodlands.”
Professor Nicola Spence, Defra’s Chief Plant Health Officer, said: “Tackling the growing threat from tree pests and diseases due to climate change is critical to protect the long-term health and resilience of our trees. Defra has invested over £9 million in ash dieback related research since the confirmation of the disease in the UK in 2012. This study, funded by Defra, contributes significantly to our knowledge base by demonstrating that tolerance to ash dieback is heritable, and highlighting that breeding programmes and natural regeneration could work together to secure the future of our native ash tree."
Sensors and observation instruments being lowered into a borehole off the coast of Japan nearly 1,500 feet below the seafloor during an International Ocean Discovery Program mission in 2016. Sensors like these transmit data in real time to researchers in Japan and at the University of Texas Institute for Geophysics, and enabled researchers to detect and describe a slow slip earthquake in motion in a new study in Science.
Credit: Photo courtesy of Dick Peterse - ScienceMedia.nl
Scientists for the first time have detected a slow slip earthquake in motion during the act of releasing tectonic pressure on a major fault zone at the bottom of the ocean.
The slow earthquake was recorded spreading along the tsunami-generating portion of the fault off the coast of Japan, behaving like a tectonic shock absorber. Researchers from The University of Texas at Austin described the event as the slow unzipping of the fault line between two of the Earth’s tectonic plates.
Their results were published in Science.
“It's like a ripple moving across the plate interface,” said Josh Edgington, who conducted the work as a doctoral student at the University of Texas Institute for Geophysics (UTIG) at UT Austin’s Jackson School of Geosciences. Slow slip earthquakes are a type of slow-motion seismic event that take days or weeks to unfold. They are relatively new to science and are thought to be an important process for accumulating and releasing stress as part of the earthquake cycle. The new measurements, made along Japan’s Nankai Fault, appear to confirm that.
This breakthrough research was made possible by borehole sensors that were placed in the critical region far offshore, where the fault lies closest to the seafloor at the ocean trench. Sensors installed in boreholes can detect even the slightest motions – as small as a few millimeters, said UTIG Director Demian Saffer, who led the study. Such movement on the shallow fault is all but invisible to land-based monitoring systems such as GPS networks.
The slow slip earthquake, captured by the team’s sensors in fall of 2015, travelled along the tail of the fault — the region close to the seafloor where shallow earthquakes can generate tsunamis — easing tectonic pressure at a potentially hazardous location. A second slow tremor in 2020 followed the same path.
Although the Nankai Fault is known to generate large earthquakes and tsunamis, the discovery suggests that this part of the fault does not contribute energy to these events – acting more like a shock absorber. The results will help researchers home in on the behavior of subduction zone faults across the Pacific Ring of Fire, the tectonic belt that spawns the planet’s largest earthquakes and tsunamis
The two events, which have only now successfully been analyzed in detail, appear as ripples of deformation traveling through Earth’s crust. Originating about 30 miles off the coast of Japan, borehole sensors tracked this unzipping motion along the fault as it moved out to sea before dissipating at the edge of the continental margin.
Each event took several weeks to travel 20 miles along the fault, and each one happened in places where geologic fluid pressures were higher than normal. The finding is important because it is strong evidence that fluids are a key ingredient for slow earthquakes. This is an idea widely circulated in the scientific community, but finding a direct connection has been elusive until now.
The last time Japan’s Nankai Fault produced a significant earthquake was in 1946. The magnitude 8 earthquake destroyed 36,000 homes and killed over 1,300 people. Although another large earthquake is expected in the future, the observations suggest the fault releases at least some of its pent-up energy harmlessly in regular, re-occurring slow slip earthquakes. The location is also important, because it shows that the part of the fault nearest the surface releases tectonic pressure independently of the rest of the fault.
Armed with that knowledge, scientists can begin to probe other regions of the fault to better understand the overall hazard it poses. The knowledge is also vital for understanding other faults, Saffer said.
For instance, Cascadia, a massive earthquake fault facing the Pacific Northwest, appears to lack Nankai’s natural shock absorber. Although some slow slip has been detected at Cascadia, none has been detected at the tsunami-generating, tail end of the fault, which suggests that it may be strongly locked to the trench, Saffer said.
“This is a place that we know has hosted magnitude 9 earthquakes and can spawn deadly tsunamis,” Saffer said. “Are there creaks and groans that indicate the release of accumulated strain, or is fault near the trench deadly silent? Cascadia is a clear top-priority area for the kind of high-precision monitoring approach that we’ve demonstrated is so valuable at Nankai.”
The borehole observatories used in the Japan study were installed by the Integrated Ocean Drilling Program and funded by the U.S. National Science Foundation. Other data were supplied by ocean floor cable observatories operated by Japan Agency for Marine-Earth Science and Technology (JAMSTEC).
Journal
Science
Method of Research
Data/statistical analysis
Subject of Research
Not applicable
Article Title
Migrating shallow slow slip on the Nankai Trough megathrust captured by borehole observatories
Article Publication Date
26-Jun-2025
Review: New framework needed to assess complex “cascading” natural hazards
Summary author: Walter Beckwith
American Association for the Advancement of Science (AAAS)
In a Review, Brian Yanites and colleagues argue the need for a unified, interdisciplinary approach to studying cascading land surface hazards. Earth’s surface is continually shaped by a range of natural processes, from slow erosion to sudden disasters like earthquakes and floods. Notably, one hazardous event can trigger a series of subsequent, interrelated disasters, or ”cascading hazards,” that unfold over timescales ranging from seconds to centuries. However, despite their growing impact on human populations, a comprehensive mechanistic framework from which to understand, predict, and manage these interconnected threats remains lacking. Here, Yanites et al. review current research on how Earth systems and the resulting land surface processes can interact in complex, sequential ways that intensify hazard risk. Unlike compound hazards, where multiple events occur independently but simultaneously, cascading hazards involve a direct causal link – one event alters the physical state of the landscape in a way that increases the likelihood of subsequent hazards. For example, earthquakes can destabilize hillslopes, raising landslide risk for years, while wildfires can transform vegetation and soil properties, amplifying the potential for debris flows during post-fire storms. According to the authors, the dynamic nature of these hazards challenges current risk assessment tools. To address this critical gap, Yanites et al. present a collaborative, cross-disciplinary framework that leverages recent technological advances and brings together atmospheric scientists, geologists, geomorphologists, engineers, and others to refine theory, models, and hazard monitoring. The authors argue that the development of a cascading hazards index could offer a promising tool by serving as an integrative, location-specific metric that synthesizes process-based models, observational data, and knowledge of hazard evolution to help communities assess these chains of evolving, interlinked hazards.
BLOOMINGTON, Ind. – When an extreme weather event occurs, the probability or risk of other events can often increase, leading to what researchers call “cascading” hazards.
For example, the danger of landslides or debris flows following wildfires in California, recent flash floods in West Virginia or when historic flooding occurred in North Carolina as Hurricane Helene made its way inland. Such occurrences leave lasting imprints on the landscape that can prime the Earth’s surface for subsequent events.
As part of a collaboration by dozens of researchers across the country, a new paper published in Science, "Cascading land surface hazards as a nexus in the Earth’s system,” outlines a framework to better predict, understand and forecast the cascade (or chain reaction) of these hazards across the landscape.
“There is a scientific need for improving our understanding of these cascading hazards,” said Brian Yanites, lead author and associate professor of earth and atmospheric sciences in The College of Arts and Sciences at Indiana University. “If we want to better prepare for events like hurricanes, we need to also understand a hurricane’s connection to other hazards.”
"How does a hurricane or an earthquake impact the landscape and change the risk for future landslides or floods? How do landslides change river systems’ flooding potential downstream because they suddenly have extra sediment? And how does the Earth’s biosphere, including the microbes converting rock to moveable sediment and tree roots holding soil in place, impact these cascades?”
The paper is the result of a two-year grant from the National Science Foundation, which supported the creation of the Center for Land Surface Hazards Catalyst, or CLaSH. Led by Marin Clark of the University of Michigan, the center catalyst brought together experts from across the country to analyze existing research gaps to better understand connections between Earth systems and processes that change as a consequence of Earth’s shifting surface.
"It's really been work that's come forward in just the last 10 years, following some major events—fires, earthquakes, hurricanes," said Clark, co-author and professor of earth and environmental science at the University of Michigan. "These have given rise to data sets and the thinking about how we can piece together these processes to predict future hazard conditions."
In real time
“It's a vivid memory for me – the Tuesday before Hurricane Helene,” said Yanites. “I emailed the research team that's been working on this new National Center, and I said, ‘This is going to be bad for southern Appalachia.’ We started monitoring it that night, knowing that there were going to be landslides and flooding. But we don't really have the scientific tools to go and say, 'How many landslides? Where are they going to be? What are the consequences for downstream processes and impacts?’”
Researchers say this new framework could also help with disaster response to build societal resilience after natural hazards.
"The federal government and state agencies are charged with reducing losses related to disasters, but we really lack an academic research community in the U.S. focused on primary basic research," said Clark. "That underpins disaster response and enables training a future workforce capable of meeting the urgent and growing need for resilience to natural hazards. This resilience is essential for both safety and economic growth."
Yanites added that this could also help the insurance industry better understand potential hazards.
"In California, we’re seeing a number of major insurance companies that aren’t offering new homeowner insurance in areas because of cascading hazards, such as a debris flow that happens five years after a wildfire,” said Yanites. “They don’t understand how to price cascading hazards into their models.”
Researchers hope to use this future framework to provide a path toward developing actionable plans for communities to prepare for cascading hazards. They also hope to create a “cascading hazards index” to give local communities context for potential cascading events.
For reporters: More information, including a copy of the paper, can be found online at the Science press package.
