Central Mongolia’s Hangay Mountains have long posed a conundrum. Rising 4 kilometers above sea level, the dome-shaped range plays a key role in shaping the region’s climate. But it couldn’t have formed in the same way as most equally tall mountain ranges.

“These mountains in central Mongolia are very far from any plate boundary, about 3,000 kilometers away from the Pacific margin,” said Pengfei Li, a geologist at the Chinese Academy of Sciences’ Guangzhou Institute of Geochemistry. “It’s very hard to understand why we have such a mountain range so far from the plate boundary.”

Li recently led research finding that geochemical evidence supports a compelling explanation of how these oddball mountains formed. The researchers proposed that at the site of the future mountains, a U-shaped bend in a tectonic plate led to an extra-thick lithosphere. A chunk of that heavy lithosphere eventually broke off and sunk into the mantle. Free of the extra weight, the crust then rebounded upward as the Hangay Mountains.

Bend and Snap

Tectonic plates are far from rigid. As they move above, below, and against each other, sections of the plates far from the boundary can develop curves and folds like a scrunched up tablecloth. Curved sections, called oroclines, are common around the world. At about 6,000 kilometers long, the Mongolian orocline is one of the longest, and the Hangay Mountains sit right at the curviest part of the orocline’s U shape.

Li and his colleagues suspected that the Hangays’ location along the orocline is no coincidence. During multiple field expeditions from 2018 through 2026, the researchers collected rock samples from several sites in the Hangay Mountains that showed signs of ancient volcanic activity. Uranium-lead dating of zircons within those samples showed that the area experienced volcanic activity in the early Cretaceous period 124–114 million years ago.

“When I saw the age, I was surprised,” Li said. “120 million years—no one had ever reported volcanoes [in the Hangay Mountains] during this period.…It’s the first discovery of volcanism for this period.”

The team also analyzed the samples for major and trace elements to determine the depth at which the rocks formed. Their geochemical analysis revealed that the rocks formed in the lithosphere 80 kilometers below the surface. They published these results in Geology in April.

It’s pretty odd that the rocks originated so deep, Li said, because the modern-day lithosphere is only 70 kilometers thick.

The team proposed that when the continental plate folded and created the Mongolian orocline 200 million years ago, the lithosphere bunched up and became thicker in the curve of the U shape. That thicker section of lithosphere, a root at least 80 kilometers thick, would have been unstable in the long term, Li explained.

The lithospheric root would have been too heavy to remain attached to the crust above for long, and a chunk of it would have eventually snapped off. When it sunk, or foundered, into the deep mantle, it would have melted and generated the volcanic activity recorded in the rocks the team studied. Free from the weight of that lithospheric root, the crust above would have rebounded into the dome-shaped mountain range visible today.

Complicated Yet Compelling

“The story that [the researchers] have put together to explain the massive Hangay topographic ‘dome’ of central west Mongolia is a compelling one that spans more than the past 200 million years of Earth history,” said Stephen Johnston, a tectonics researcher at the University of Alberta in Canada who was not involved with this research. Past research into the Iberian orocline suggested that oroclines might lead to lithospheric thickening, and this explanation of the Hangay Mountains fits that narrative.

“Their story, though complicated, makes a great deal of sense and in a way provides affirmation of a prediction made some time ago regarding oroclines,” Johnston added.

Johnston said that the new explanation of how the Hangay Mountains formed makes him wonder why it took so long—80 million years—between when the orocline formed and when the lithospheric root sank.

“This seems a long time for a gravitationally unstable mantle root to have remained attached to the overlying crust,” he said. He hopes that future work can help determine whether this process has taken place at other oroclines around the world and has simply been overlooked or whether there is something special about the Mongolian orocline.

Li and his team have turned their attention to how the formation of the Hangay Mountains shaped the region’s ancient climate. Today, the towering mountain range prevents moist air from northern Mongolia from reaching the parched Gobi Desert in the south. They hope to connect how a process deep underground, like lithospheric foundering, affected the paleoclimate and, consequently, the region’s habitability.

“It’s very new to try to understand the Earth’s habitability from a deeper sense,” Li said.

—Kimberly M. S. Cartier (@astrokimcartier.bsky.social), Staff Writer

Correction 18 May 2026: The distance between the Hangay Mountains and the Pacific plate margin has been corrected. The location of newly discovered volcanic activity has been corrected.

This news article is included in our ENGAGE resource for educators seeking science news for their classroom lessons. Browse all ENGAGE articles, and share with your fellow educators how you integrated the article into an activity in the comments section below.

Citation: Cartier, K. M. S. (2026), Mongolian mountains rose when the crust bounced back, Eos, 107, https://doi.org/10.1029/2026EO260153. Published on 15 May 2026.

Text © 2026. AGU. CC BY-NC-ND 3.0
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LONDON, June 3 — Britain has imposed new conduct requirements on Google’s search services, including allowing publishers to stop their content being used to power the US tech giant’s AI features, as the watchdog ramps up its oversight.

The country’s Competition and Markets Authority has flagged concerns about Google’s dominance in search, designating the company with the “strategic market status” that allows it to set targeted rules to increase trust and transparency.

Google accounts for more than 90 per cent of UK queries and the regulator said in January it wanted to give publishers more control over how their content was used.

The CMA today said the requirements imposed on Google under the digital markets competition regime gave “publishers more control and stronger bargaining power over the use of their content,” ‌while securing a fair deal.

News websites and other publishers have seen click-through rates drop ⁠sharply as a result of users relying ⁠on overviews generated with the help of AI.

Google said ⁠it was providing “new resources, insights ⁠and control for website owners” ⁠to navigate the changes in how users find and understand information using generative AI.

It said it was testing a new control that lets publishers manage how their links ⁠and content appear in generative AI search features.

Sites that opt out would not receive traffic from AI Overviews and AI Mode, it said in a blog post, but the controls would not affect traditional search results.

It said it was also increasing the number of links in AI responses and it was starting to roll out ⁠new insights for publishers.

The CMA said Google would be required to make sure content from publishers, including news organisations, was properly attributed in AI-generated search results, using ⁠clear links.

“Google has recently announced changes to its search business and the requirements we’ve introduced ⁠today are designed ⁠to respond to what Google is doing now and in the future,” CMA Chief Executive Sarah Cardell said.

Google faces increasing regulatory scrutiny across the world, including in the United States and ‌European Union, and the company in March said it was developing new search controls to address British competition concerns. — Reuters

Pejasar posted a photo:

Demonstrations took off in Washington and across US as Trump throws first private, for-profit sporting event ever held on White House grounds

Dozens of people stood across the entrance gates to the Ellipse, the park south of the White House, on Sunday afternoon, holding protest signs and chanting as the president prepared to host seven mixed martial arts fights on the lawn.

Thousands of fight fans streamed past the protesters into the sprawling public viewing area that the Trump administration and the Ultimate Fighting Championship (UFC), which is hosting the fights, erected steps from the White House. The cage fights, marketed as a celebration of the country’s “fighting spirit” ahead of its 250th anniversary, are being held on Donald Trump’s 80th birthday.

Truus, Bob & Jan too! posted a photo:

Vintage postcard. Filmex NV. Ed. Takken, Utrecht. Magda Schneider in Robinson soll nicht sterben/ The Girl and the Legend (Josef von Baky, 1957), released in The Netherlands as Droom-eiland (Dream Island).

German singer and actress Magda Schneider (1909-1996) is best known as the mother of film star Romy Schneider, but in the 1930s, 1940s and 1950s s she herself starred in some 40 films. First she appeared on the screen as a charming Wiener mädel (Viennese girl) and after the war she often played the understanding mother or aunt.

The United States Trade Representative’s office announced in a press release this week that it will conduct three rounds of negotiations with Mexico about the upcoming Canada–United States–Mexico Agreement (CUSMA) review on July 1 – all of which will continue to exclude Canada from the discussions. 

While Canada-U.S. Trade Minister Dominic LeBlanc has indicated he will head to Washington next week, 

Canada’s Chief Trade Negotiator Janice Charette and Prime Minister Mark Carney’s Office of the Privy Council have remained tight-lipped about the upcoming CUSMA review. 

rabble.ca had an opportunity to do a Question and Answer with the Privy Council Office this week, to clarify some expectations about the next phase of negotiations with the United States and Mexico.  

1. What’s it like working with the USTR right now. Is it actually adversarial or confrontational? Jamieson Greer has made several remarks in the past few months indicating that it might be, so we’re trying to filter out political theatre from reality.

Canada continues to be a ready and willing trading partner, favouring durable outcomes built on comprehensive and pragmatic solutions and not short-term fixes.

The proposals Canada has advanced are serious and substantive, having the potential to generate hundreds of billions of dollars in economic value for American industries and workers in exchange for real relief from the unfair tariffs imposed on Canadian products.

As is appropriate, Canada does not negotiate publicly and will continue to engage through diplomatic channels in a manner that reflects the seriousness and importance of these discussions.

2. Can you give me an indication of how your office is working with Mexico directly at this point? Are there effects from the recent Mexican Trade missions that relate your work in any way? 

Canada recently held the latest round of its own bilateral engagements with Mexico, and those discussions were very positive and productive.

Canada remains fully prepared for any and all discussions with the U.S. and Mexico on trade issues and we are engaged in substantive and concrete discussions with both countries.  We are confident in the strength of our position.

As we near the joint review of the CUSMA, we are engaging on a continuous basis with industry and labour representatives as well as provincial and territorial governments to ensure that we can exchange relevant information and keep key partners up-to-date.

We have been clear and consistent with the United States that we are ready to launch the joint review the moment they are. There continues to be meetings between Canadian and American trade officials on a regular basis.

With respect to the upcoming U.S.-Mexico meetings, discussions between any two partners are a normal part of diplomatic engagement, as they serve to address issues particular to that bilateral relationship.

To be clear, any review or renegotiation of the core structure of CUSMA, including foundational elements such as rules of origin, cannot happen without Canada. Canada is committed to maintaining the CUSMA as a trilateral agreement, and any consideration of changes or modifications requires all three parties at the table.

Canada continues to advance its own bilateral discussions, remains in close contact with both partners, and stands ready to move forward with trilateral negotiations as soon as all three parties are prepared to engage together.

3. What are the issues that are being prioritized in the CUSMA review? 

Canada and the United States share one of the most comprehensive and mutually beneficial economic relationships in the world, and Prime Minister Carney’s remarks reflect our commitment to deepening that partnership in a way that works for both countries.

Examples of sectors where deeper integration holds the most significant potential include energy, steel and aluminum, softwood lumber, agriculture, and the automotive sector.

These are areas where our two economies are already deeply integrated, where Canadian inputs form part of high-value supply chains, and where a strengthened, rules-based trading framework can deliver real benefits for workers, farmers, businesses, and communities on both sides of the border.

It is also important to remember that more than 70 per cent of what Canada sends across the border is not finished consumer goods. They are inputs like energy, raw materials, critical minerals, aluminum, steel that go directly into American manufacturing. 

In short, Canadian exports do not displace American production but rather help make it possible and increase the ability of companies in both countries to compete globally.

That said, the Canada-U.S. relationship extends well beyond any single sector or agreement.

More broadly, Canada shares the U.S.’s concerns about unfair competition from non-market economies and has taken steps to protect our industries from unfair trade practices, for example in the steel and aluminum sectors. We are prepared to work collaboratively with the U.S. in this regard.

Canada has consistently been a strong, stable, and reliable partner in trade, in hemispheric security, in defence, and across the full range of shared interests that define our partnership.

The post rabble Q&A with Privy Council Office on CUSMA review appeared first on rabble.ca.

simppdess posted a photo: