Newswise — New research from Adelaide University has revealed that geological processes dating back billions of years are critical to locating the rare earth elements needed for modern technologies and the global clean energy transition.

Published today in Science Advances, the study shows a strong global link between ancient subduction zones – where tectonic plates collide – and the formation of rare earth element (REE) deposits and carbonatites, a type of hot molten rock called magma, known to host these valuable resources.

Rare earth elements are essential components in technologies such as electric vehicles, wind turbines, smartphones, and defence systems. However, locating economically viable deposits remains a major global challenge.

Led by Professor Carl Spandler from the School of Physics, Chemistry and Earth Sciences, the research team reconstructed Earth’s geological history over the past two billion years using advanced plate tectonic modelling.

They identified regions of the Earth’s mantle that had been fertilised by subduction processes, where material from one tectonic plate is forced beneath another, releasing fluids and elements into the overlying mantle.

The Adelaide University researchers found that these fertilised mantle regions now underlie approximately 67% of carbonatites and 72% of REE deposits formed over the past 1.8 billion years. For older deposits, that figure rises to 92%.

Prof Spandler said the findings provide compelling evidence that ancient subduction zones play a fundamental role in creating the conditions needed for rare earth deposits to form.

“This research shows that the ingredients for these critical mineral deposits were put in place many million to even billions of years ago,” Prof Spandler said. “By identifying where these ancient processes occurred, we can significantly narrow down the search areas for future discoveries.”

The study also challenges previous theories that linked these deposits primarily to mantle plumes –columns of hot material rising from deep within the Earth.

Instead, the research highlights a two-stage process: an initial fertilisation of the mantle during subduction, followed – sometimes hundreds of millions or even billions of years later – by a separate event that triggers melting and magma formation.

“This time lag is one of the most surprising aspects of our findings,” Prof Spandler said. “It shows that the Earth’s mantle can store these enriched zones for incredibly long periods before the right conditions arise to form mineral deposits.”

The research team mapped these regions across the globe, finding they cover around 35% of the Earth’s continental crust. Importantly, areas where multiple subduction events overlapped were found to host particularly high concentrations of REE deposits.

Co-author Dr Andrew Merdith said the work has significant implications for mineral exploration.

“By focusing on these ancient tectonic zones, exploration companies and governments can take a more targeted and efficient approach to finding new deposits,” Dr Merdith said. “This is especially important as demand for rare earth elements continues to grow.”

The findings also provide new insights into Earth’s geological evolution, including how continents have been shaped over billions of years and how deep Earth processes influence surface resources.

Beyond resource exploration, the study highlights the long-term storage of carbon and water in the Earth’s mantle, with implications for understanding past climate and volcanic activity.

The research was conducted in collaboration with the ARC Centre in Critical Resources for the Future.

‘Linking carbonatites, rare earth ores, and subduction-fertilized mantle lithosphere’ is published in Science Advances. DOI: 10.1126/sciadv.aeb2942

BYLINE: Kitta MacPherson

Newswise — Meteor impacts may have helped spark life on Earth, creating hot, chemical-rich environments where the first living cells could take shape, according to research integrated by a recent Rutgers University graduate.

“No one knows, from a scientific perspective, how life could have been formed from an early Earth that had no life,” said Shea Cinquemani, who earned her bachelor’s degree in marine biology and fisheries management from the Rutgers School of Environmental and Biological Sciences in May 2025. “How does something come from nothing?”

 Cinquemani is the lead author of a scientific review, published in the peer-reviewed Journal of Marine Science and Engineering, examining where life may have first formed on Earth. The paper focuses on hydrothermal vents, places where hot, mineral-rich water flows through rock and emerges into surrounding water, creating the chemical conditions and energy gradients needed for complex reactions.

 Her research points to hydrothermal systems created by meteor impacts as a potentially critical and underappreciated setting for the origin of life, strengthening the case beyond conventional deep-sea vent theories. Cinquemani said such systems would have been widespread on early Earth, making them especially compelling environments for life to begin.

 The paper, co-authored with Rutgers oceanographer Richard Lutz, marks a rare achievement for a recent undergraduate whose work began as a class assignment and was transformed into a publication in a highly respected scientific journal.

 “It’s amazing,” Lutz said. “You often have undergraduates that are part of papers – faculty choose undergraduates all the time to work on papers and projects. But for an undergraduate to be the lead author is a huge deal.” 

 The project started in the spring of Cinquemani’s senior year in a course called “Hydrothermal Vents,” taught by Lutz, a Distinguished Professor in the Department of Marine and Coastal Sciences. Cinquemani’s assignment was to examine whether hydrothermal vents on Mars could have been harbingers of life there.

 “I was like, ‘I know nothing about this topic,’” she said. “Thinking about the origins of biology on another planet was like, whoa. Not sure how I’m going to do this.” The topic went beyond her usual comfort zone of biology and extended into chemistry, physics and geology, she said.

 Cinquemani expanded the assignment after graduation into a full scientific review of both impact-generated and deep-sea vent systems, which was accepted after what Lutz described as a demanding peer-review evaluation.

 “I have never seen such a rigorous review process,” Lutz said. “There were 15 pages of comments and five different rounds of reviews. She had the patience and perseverance, and the paper turned out magnificently.”

 Deep-sea hydrothermal vents have long been considered a possible birthplace of life. Discovered in the deep ocean in the late 1970s, these systems host entire ecosystems that thrive without sunlight. Instead of photosynthesis, microbes use chemical energy from compounds released by vent fluids, such as hydrogen sulfide, in a process known as chemosynthesis.

 Some deep-sea vents are powered by heat from the Earth’s interior near volcanic activity while others are driven by chemical reactions between water and rock that generate heat without magma. This heat facilitates chemical processes and provides a warm oasis in the otherwise barren seafloor of the deep ocean. 

 Cinquemani’s paper places more focus on a different category that has recently begun gaining attention: hydrothermal systems created by meteor impacts.

 When a large meteor strikes Earth, the impact generates intense heat and melts surrounding rock. As the area cools and water fills the crater, a hot, mineral-rich environment can form, similar in some ways to deep-sea vents.

 “You have a lake surrounding a very, very warm center,” Cinquemani said. “And now you get a hydrothermal vent system, just like in the deep sea, but made by the heat from an impact.”

 To explore how these systems might support life, she examined research on three well-studied crater sites that span vastly different periods of Earth’s history. The oldest is the Chicxulub impact structure beneath Mexico’s Yucatán Peninsula, formed about 65 million years ago and later shown to have hosted a long-lived hydrothermal system. Next is the Haughton impact structure in the Canadian Arctic, formed about 31 million years ago. The youngest is Lonar Lake in India, created about 50,000 years ago, where the crater still contains water and offers clues about how these systems evolve over time.

 These impact-generated systems may last thousands to tens of thousands of years, giving simple molecules time to form more complex structures that could lead to life.

 Scientists say such environments may have been especially important on early Earth, which experienced frequent asteroid impacts. In that sense, events often seen as destructive also may have helped create the conditions for life.

 The idea builds on decades of research into deep-sea vents while expanding the search for life’s origins into new territory.

 Lutz helped explore these deep-sea environments several decades ago when they were still a scientific mystery. As a young postdoctoral researcher, he joined the first biological expedition to study hydrothermal vents and descended more than a mile beneath the ocean surface in the research deep-sea submersible Alvin, where he observed thriving communities of organisms in total darkness.

 Those dives helped open a new field of research and shaped scientists’ understanding of how life can exist in extreme environments without sunlight.

 “We have talked for many years about the possibility that life may have originated at deep-sea hydrothermal vents,” Lutz said.

 Cinquemani’s work brings together those long-standing ideas with newer evidence that impact-generated systems also could play a role and may in some cases offer favorable conditions for early chemical reactions.

 The implications extend beyond Earth. Hydrothermal activity is thought to exist on the ocean floors of icy moons such as Jupiter’s Europa and Saturn’s Enceladus, and may have existed in impact craters on young Mars. If these environments on Earth can support the chemistry of life, they could become key targets in the search for life elsewhere.

 For Cinquemani, the work is driven by curiosity.

 “Humans are insanely curious beings,” said Cinquemani, who works as a technician at Rutgers’ New Jersey Aquaculture Innovation Center in Cape May, N.J., where she supports aquaculture research while preparing to pursue advanced study in marine science. “We question everything. We may never know exactly how we began, but we can try our best to understand how things might have occurred.”

Explore more of the ways Rutgers research is shaping the future.

Newswise — For decades, global soil moisture monitoring from space has depended on reference datasets. Satellite observations, while indispensable, are rarely used alone; instead, their retrieval algorithms are typically calibrated or constrained using external soil moisture products derived from other satellites, models, or reanalysis systems. This practice has helped stabilize retrievals, but it has also introduced fundamental limitations—reducing transparency, constraining transferability across regions, and complicating long-term consistency as reference products evolve. A growing question in Earth observation is whether this dependence is truly unavoidable.

In a study published (DOI: 10.34133/remotesensing.0939) on January 7, 2026, in the Journal of Remote Sensing, researchers from the Chinese Academy of Sciences, Peking University, and the China Meteorological Administration present PHYsics-based Soil rEflectivity Retrieval (PHYSER)—a physics-based framework for spaceborne GNSS-R soil moisture retrieval. The study demonstrates that global soil moisture can be retrieved independently, without relying on any external soil moisture referenSatellite Observationce products.

A long-standing constraint in satellite soil moisture retrieval

Soil moisture governs the exchange of water, energy, and carbon between the land surface and the atmosphere, influencing droughts, floods, ecosystem functioning, and agricultural productivity. Satellite remote sensing has become essential for monitoring soil moisture at regional to global scales, yet existing approaches face persistent challenges.

Conventional microwave sensors provide physically meaningful measurements but often struggle to balance spatial resolution, temporal coverage, and mission cost. More recently, Global Navigation Satellite System Reflectometry (GNSS-R) has emerged as a promising alternative. By passively receiving L-band signals continuously transmitted by navigation satellites such as GPS and BeiDou, GNSS-R offers low power consumption, all-weather capability, and dense spatiotemporal sampling.

Despite these advantages, most GNSS-R soil moisture retrieval methods still rely on empirical or semi-empirical relationships calibrated against external soil moisture products. This reliance weakens the physical interpretability of the results and limits their robustness when applied across regions, time periods, or future satellite missions. As GNSS-R constellations rapidly expand, the absence of an independent, physics-based retrieval framework has become a critical bottleneck.

Retrieving soil moisture from physical principles

PHYSER addresses this bottleneck by rethinking GNSS-R soil moisture retrieval from first principles. Rather than fitting GNSS-R observations to existing soil moisture datasets, the framework derives soil moisture directly from the physical interaction between navigation signals and the land surface.

At the core of PHYSER is the accurate reconstruction of soil surface reflectivity from GNSS-R measurements. This is achieved through a stepwise physical correction strategy. First, system-related biases inherent to the GNSS-R “multi-transmitter, single-receiver” observation geometry are corrected using inland water bodies as stable natural calibration targets. This step ensures consistency across different navigation signals and viewing geometries.

Second, land surface effects—particularly vegetation attenuation and surface roughness—are explicitly corrected using a physically based radiative transfer model. These land surface factors are shown to introduce larger uncertainties than satellite system errors, underscoring the importance of addressing them through physics-based correction rather than statistical adjustment.

With these corrections applied, soil reflectivity is transformed into soil permittivity using Fresnel equations. Soil moisture is then retrieved using established dielectric mixing models informed by global soil texture data.

Independent validation across space and ground observations

The PHYSER framework was evaluated using one year of observations from the BuFeng-1 A/B twin satellites, China’s first spaceborne GNSS-R mission designed for technology demonstration. The retrieved soil moisture fields were compared with SMAP satellite products, ERA5-Land reanalysis data, and hundreds of in situ measurement sites worldwide.

Across diverse climatic and land surface conditions, the PHYSER-based retrievals show strong spatial and temporal consistency with these independent datasets. While retrieval errors are comparable to—or only slightly higher than—those of empirical GNSS-R approaches, PHYSER achieves this performance while remaining fully independent of reference soil moisture products.

“This work shows that GNSS-R soil moisture retrieval does not have to be a statistical imitation of other products,” said a member of the research team. “By grounding the retrieval in physics, we gain transparency, robustness, and the ability to extend the method to future missions without retraining against external datasets.”

Implications for future Earth observation missions

As GNSS-R missions multiply and satellite constellations become denser, the need for scalable and physically interpretable retrieval methods is becoming increasingly urgent. PHYSER provides a pathway toward soil moisture monitoring that is not tied to any specific reference product or satellite mission.

The framework has the potential to strengthen climate reanalysis, improve hydrological forecasting, and support agricultural decision-making, particularly in data-sparse regions. With further refinement—especially in densely vegetated environments—PHYSER could help enable operational GNSS-R soil moisture products that complement, and potentially stand alongside, traditional microwave remote sensing systems.

###

References

DOI

10.34133/remotesensing.0939

Original Source URL

https://spj.science.org/doi/10.34133/remotesensing.0939

Funding information

This study is supported by the Chinese Academy of Sciences, the Shandong Provincial Natural Science Foundation (Grant No. ZR2024QD048), the National Natural Science Foundation of China (NSFC) project (Grant No. 42471511), the BUFENG-1 Application Extension Program of the China Spacesat Co., Ltd., the ESA-MOST China Dragon5 Programme (ID.58070), the Fengyun Application Pioneering Project (FY-APP-2021.0301), the Beijing Nova Program (Grant Nos. 20230484327 and 20240484540), and the Hunan Provincial Natural Science Foundation project (Grant No. 2024JJ9186).

About Journal of Remote Sensing

The Journal of Remote Sensing, an online-only Open Access journal published in association with AIR-CAS, promotes the theory, science, and technology of remote sensing, as well as interdisciplinary research within earth and information science.

Newswise — Around 56 million years ago, Europe and North America began pulling apart to form what became the ever-expanding North Atlantic Ocean. Vast amounts of molten rock from Earth’s mantle reached the ocean floor as the crust stretched and thinned, creating a volcanic rifted margin between Norway and Greenland, a marine feature that has intrigued scientists for decades.

They have long argued over why so much magma surfaced here in what was among the biggest volcanic events in Earth’s history, one that is implicated in a period of intense global warming during the Eocene Epoch. Was a deep, superhot mantle plume responsible, or did crustal thinning play the bigger role?