Ancient tectonic processes the key to locating rare minerals

Adelaide University

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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

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Journal

Science Advances

DOI

10.1126/sciadv.aeb2942 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

Linking carbonatites, rare earth ores, and subduction-fertilized mantle lithosphere

Article Publication Date

8-Apr-2026

 

Researchers warn against securitized response to global biodiversity loss

University of East Anglia

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Scientists have warned that a new UK Government report on global biodiversity loss and national security risks distorting evidence and driving ineffective policy by framing ecological degradation and its impacts on migration as a security threat.

The report, ‘Global biodiversity loss, ecosystem collapse and national security’, was published in early 2026 and argues that accelerating biodiversity loss and ecosystem collapse pose mounting security threats to the UK.  

Writing in the journal PLOS Climate, researchers from the University of East Anglia (UEA) and University of Exeter welcome the attention on biodiversity and nature loss. However, they say the report which views environmental change and biodiversity loss - alongside climate impacts - through a national security lens could lead to poorly targeted actions and policy.

Past attempts to cast climate issues as security risks often relied on simplified causal claims, shifting authority towards military and border agencies in policymaking, and ultimately failed to motivate constructive climate action.

Instead, they sometimes triggered political backlash or restrictive migration policies. The researchers warn this strategy risks repeating the problems associated with the securitisation of climate change.

Attempting to galvanise action by framing any environmental issue as a security threat to elicit positive action creates its own risks, relying on “ethically questionable foundations” and is often based on overly simplified evidence.

Concerns over migration claims

The researchers highlight migration as a major weakness in the report’s analysis, arguing the evidence does not support claims that biodiversity loss will drive large-scale international migration towards the UK.

Decades of empirical research show that most environmentally-linked migration is short distance, occurring within countries or neighbouring regions - not across continents.

Dr Mark Tebboth, of UEA’s School of Global Development and lead author of the opinion article, said: “Biodiversity loss and ecosystem collapse are rightly recognised as serious global risks and the UK Government report raises an important and timely issue around the security implications of accelerating ecological degradation.

“However, it fails to present a credible causal link between biodiversity loss and UK-bound migration. Environmentally-linked migration is translated directly into security impacts for the UK, but current evidence does not support this assumption.

“Conflating environmental stress with national security risks leads to speculative conclusions, distracts from real threats, and misdirects resources.”

The researchers say the report also overstates the evidence by promoting a poorly sourced and mischaracterised claim that a 1 per cent rise in food insecurity leads to a 1.9 per cent rise in migration.

That figure originates from a non-peer-reviewed report based on a 2017 World Food Programme study - and the original study examined refugee flows from armed conflict, not general migration or biodiversity loss. Applying it to broad future migration trends is, the researchers say, “inappropriate”.

Security lens risks narrowing responses

“Positive actions to build resilience include supporting farmers to avoid food insecurity through food production harmonious with nature; avoiding urban development on flood plains to make space for water and nature; and accelerating climate action to avoid the consequences of runaway climate change,” said Dr Tebboth, Associate Professor in Environment and Global Development.

“But securitising biodiversity loss creates a policy environment where certain voices within government such defence and border agencies can disproportionately shape government responses. This sidelines institutions better suited to address ecological decline, food system fragility, and community resilience.”

The authors also caution that security-driven narratives tend to produce worst case scenarios such as mass displacement - scenarios not supported by current evidence.

Overemphasising such risks can obscure the most significant, and empirically grounded, risks to the UK associated with biodiversity loss, including the erosion of livelihoods and food systems, governance pressures in environmentally-stressed regions, and the growing vulnerability of populations who may be unable to move or adapt.

Call for evidence-based, non-securitised policy

The team warns that unfounded claims about mass displacement risk distorting the national debate and could push the UK towards counterproductive policy decisions.

“While biodiversity loss and ecosystem collapse are indeed major global threats, we argue the UK must ground its national risk assessments in rigorous evidence rather than deterministic models or speculative migration projections,” said Dr Tebboth.

“Policy should focus on protecting and restoring ecosystems critical to food security, supporting governance and adaptive capacity in vulnerable regions, and investing in early warning systems that track livelihood and ecological stress. They should avoid unfounded claims about mass displacement triggered by biodiversity decline.”

‘Risks and limits from a securitisation framing of nature and biodiversity crises: Lessons from climate change’, Mark Tebboth, Sarah Redicker, Neil Adger, Reetika Revathy Subramanian, is published in PLOS Climate on April 8.

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Journal

PLOS Climate

DOI

10.1371/journal.pclm.0000873 

Article Title

Risks and limits from a securitisation framing of nature and biodiversity crises: Lessons from climate change

Article Publication Date

8-Apr-2026

LA Teachers Strike: 68,000 Education Workers in 3 Unions Set to Walk

Glenn Sacks

 April 8, 2026

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Image by LaTerrian McIntosh.

Three unions representing 68,000 education workers are set to strike against the Los Angeles Unified School District beginning Tuesday, April 14.

United Teachers Los Angeles has been working without a contract for nine months, in contravention of the long-held labor position of “no contract, no work!”, and we have been negotiating for over a year. Service Employees International Union Local 99 and Associated Administrators of Los Angeles have also been unable to reach an agreement with LAUSD.

In 2019, UTLA struck alone. In 2023, SEIU, which represents LAUSD bus drivers, special education assistants, custodians, and cafeteria workers, launched a three-day “Unfair Practice Charge” strike, and UTLA, refusing to cross their picket lines, conducted a three-day Solidarity Strike.

This time the three unions plan to strike together.

What Is This Strike About?

LAUSD claims it is in a financial crisis and doesn’t have the money to pay the salaries and other provisions the three unions want. UTLA and its allied unions believe LAUSD is vastly overstating its financial challenges.

LAUSD started this school year with a $5.03 billion reserve, its highest ever. In fact, LAUSD has greatly underprojected reserves every year from 2013 to 2025.

Moreover, the percentage LAUSD holds in reserve is often double or triple that held by other major California school districts. Legally, LAUSD is required to hold only 1% of its budget in reserve ($188 million).

To Be Fair to LAUSD…

…the district does face real problems, as the unaffordability ​of housing and changing demographics have combined to shrink LAUSD enrollment, and federal immigration actions have stemmed the flow of new students into LAUSD.

Yet LAUSD attempts to link these problems to contract negotiations and greatly exaggerates its challenges in order to mislead Los Angeles education workers into accepting an inferior contract.

LAUSD Negotiator: Teachers Take Away Money from Our Students

At a recent LAUSD-UTLA session, a consultant employed by LAUSD actually told the many educators present “all teachers are taking from their students to fund teachers’ healthcare.”

As charming as this accusation was, it isn’t an outlier. In recent months LAUSD has tried to make it appear as if UTLA’s demands are outlandish, and has implied that they can’t be met, or can only be met at the expense of others. Those others include:

Younger teachers, who LAUSD implies may be displaced or laid off due to UTLA’s demands

Non-UTLA education workers, such as those at LAUSD’s central offices (aka “Beaudry”)

Students, who will lose out as money is diverted away from them and towards educators

None of this is true, but it makes good PR.

And the Master of PR Is…

…LAUSD’s Alberto Carvalho. As the battle heated up late last year and early this year, Superintendent Carvalho, having fed the media LAUSD’s financial distortions and gotten headlines screaming “Layoffs, Cuts and Closures Are Coming” and “LAUSD warns of layoffs and cuts”, etc., did a Clinton-style “I feel your pain” routine, telling reporters that when it comes to losing teachers, he cares deeply and is “working around the clock to minimize any and all impact.”

The message is: LAUSD is in deep crisis but our superintendent is doing everything he can to save teachers’ jobs and (sigh) UTLA leadership just refuses to be reasonable and understand the position he and LAUSD are in.

Except the only “crisis” is the one he’s manufactured and then is swooping in to “save” us from. This man is talented.

Will LAUSD Bring Carvalho Back?

Carvalho was put on administrative leave by LAUSD on February 27 after his home and office were raided by federal agents as part of a Department of Justice investigation into the failed artificial intelligence company, AllHere, that the district contracted with for a chatbot called Ed.

Carvalho has recently expressed a desire to come back to work, but his return in the near term seems unlikely. He is a charismatic leader, and leaving him out of the picture disrupts LAUSD’s leadership. Nonetheless, LAUSD has good reasons to leave him on the sideline.

For one, he and the story surrounding him would be a distraction, and during last-minute negotiations or a strike there could, at any moment, be a disruption from new raids, a criminal indictment, or a public revelation of more damaging information.

Also, while it is certainly possible that in the end Carvalho will be cleared of wrongdoing, there’s no doubt his starpower has been dimmed by the scandal. For LAUSD, this diminishes the potential value of his return.

While I don’t wish Carvalho any harm personally, his demise, or at least his temporary demise, is a break for UTLA. He’s very skilled at public relations and working the media, far more so than our 2019 adversary, then-superintendent Austin Beutner. Also, in a school district filled with immigrant families, he has his own heroic undocumented immigrant story, and speaks fluent Spanish. I was not looking forward to going up against him in a strike.

Carvalho has been replaced, for now, by Acting Superintendent Andres Chait.

Mr. Chait, That’s an Odd Thing to Say for a Guy on the Eve of Provoking a Strike…

On the one-month anniversary of becoming LAUSD Acting Superintendent, Chait sent LAUSD employees an email emphasizing, “We are Los Angeles UNIFIED” and tells us “From our students and families to our teachers and staff, from those who support our classrooms to our civic and philanthropic partners, we are one Los Angeles Unified.”

Why Doesn’t LAUSD Make AALA a Better Offer?

It’s indicative of how unreasonable LAUSD’s bargaining position has been that they’ve even managed to alienate their own partners in management. I assume that one reason for LAUSD’s surprising intransigence with its management partners is that whatever raise AALA gets, UTLA and probably Service Employees International Union will demand at least as much.

Still, strategically LAUSD has put itself in a bad position. In the pre-strike/strike public relations contest in the media, how can LAUSD claim they’re being reasonable when even their own school-site management is against them?

For many years, LAUSD avoided disputes with AALA because AALA had the so-called “me too”, whereby whatever pay raise UTLA won, the administrators got it too. Many in UTLA have long complained about this, but I’ve always ​disagreed.

“Me too” divided administrators’ loyalties, particularly during contract negotiations and strikes. One could see this in 2019 and 2023–while LAUSD principals and vice-principals followed LAUSD’s directives, for the most part their hearts were clearly not in it.

In 2023 LAUSD Labor Relations removed the “me too” clause from compensation negotiations.

Associated Administrators of Los Angeles, which represents principals and assistant principals, is only being offered a 7% pay raise over two years–4% for 2025–26 and 3% for 2026–27.

AALA: a Prediction

As it stands right now, according to Chait, schools will be closed during the strike. He explains:

“When you have three unions, UTLA, SEIU and AALA, who have all indicated that they would strike together, it is exceedingly difficult, if not nearly impossible, to maintain schools open during that scenario.”

I think LAUSD is being foolish, and I expect they’ll make AALA a decent enough offer that they won’t strike with us. I hope I’m wrong.

Striking Alongside Our Bosses?

Striking alongside our bosses is new in LAUSD labor relations, and it does feel a little odd.

The other day my principal said, “It looks like you and I will soon be on the picket line together.” I put my arm around his shoulder and said, “Yes, all of us, comrades fighting for the proletariat against the bosses, the very essence of class struggle–I can hardly wait!”

I’m not sure how comfortable he was with the idea when it’s put that way…

LAUSD–They’re Underpaid, So You Should Accept Being Underpaid

In lecturing us on why we shouldn’t get a bigger raise, LAUSD says, “Over the past 10 years, the 20 biggest school districts in California gave an average pay raise of about 30%. During that same time, LAUSD gave a 36% increase—the highest among comparable districts in the state.” But teachers throughout the state–throughout the country–are underpaid. Because others are underpaid, should we accept being underpaid too?

It’s reminiscent of the famous story about baseball Hall of Famer Joe DiMaggio’s salary negotiations after his stellar sophomore season in 1937. DiMaggio demanded a $40,000 salary. Yankee business manager Ed Barrow told him this was impossible, after all, even Yankee Hall of Famer Lou Gehrig, Barrow claimed, wasn’t making $40,000.

Barrow expected that DiMaggio, just 22 years-old, without an agent, and in an era where baseball players were bound to their teams in perpetuity by the infamous reserve clause, would quickly fold.

Instead, the young DiMaggio looked at Barrow and plainly stated, “Then Mr. Gehrig is a badly underpaid player.”

Glenn Sacks teaches social studies at James Monroe High School in the Los Angeles Unified School District. He was recently recognized by LAUSD Superintendent Austin Beutner for “exceptional levels of performance.”