What 8-million-year-old stalagmites reveal about Saudi Arabia’s lost green past

Special What 8-million-year-old stalagmites reveal about Saudi Arabia’s lost green past
Researchers at Northumbria University discovered there were multiple humid phases in central Arabia over millions of years. (Getty Images)
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Updated 27 April 2025
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What 8-million-year-old stalagmites reveal about Saudi Arabia’s lost green past

What 8-million-year-old stalagmites reveal about Saudi Arabia’s lost green past
  • Researchers discovered there were multiple humid phases in central Arabia that likely fed ancient river systems
  • These wet periods likely transformed arid deserts into green corridors for animal and early human migration out of Africa

LONDON: Two major surprises greeted researchers in the Department of Geography and Environmental Sciences at Northumbria University when they returned to the UK from Saudi Arabia with samples of ancient stalagmites collected in caves northeast of Riyadh.

The plan was to use the samples to identify specific humid phases in central Arabia over the past million years or so which would have temporarily “greened” the more usually arid region, transforming the so-called Saharo-Arabian Desert Barrier into a land bridge across which many mammalian species ­—­ including early humans — would have made the journey out of Africa.




Hubert Vonhof (right), geologist at the Max Planck Institute for Chemistry, and Alexander Budsky, scientist at the State Museum in Kärten, were part of the team that analyzed dripstones from Saudi Arabian caves. (Supplied)

The initial surprise was that the first, commonly employed technique they used to date such samples did not work.

Two different radiometric dating methods are used to date the calcium carbonate laid down in stalagmites — uranium-thorium (U-Th) and uranium-lead (U-Pb) — which both measure the extent to which radioactive isotopes in the material have decayed.

“At first we suspected the stalagmites might be quite a lot younger, so we used the uranium-thorium method,” said Monika Markowska, a senior research fellow in the Geography and Environmental Sciences Department at Northumbria University in Newcastle, England.

“This method is good only for about 600,000 years, and we kept finding we couldn’t date anything.”

Then came the second surprise, revealed in a paper published in the journal Nature this month.

“So, we switched to the uranium-lead method and all of a sudden it revealed just how old these stalagmites were,” she said.

“There was this sudden realization in the lab: ‘Oh my goodness, these are 8 million years old.’ It was quite a moment.”

At a stroke, the story of life in central Arabia had been pushed back more than 7 million years.

Stalagmites, stalactites and “flowstones,” known collectively as speleothems, are created on the floors, roofs and walls of caves by rainwater dripping through from the surface.




A cross-section of one of the stalagmites taken for analysis. (Supplied)

As water passes through the soil or rock above a cave, it collects minerals, including calcium carbonate. In the case of stalagmites, over many millennia, these minerals form conical towers, slowly growing up from the floor of the cave.

The age and rate at which these stalagmites have grown can be accurately measured using various methods of radiometric dating, which calculates a material’s age by measuring the presence of radioactive elements.

Until recently, evidence of environmental conditions in Arabia extended back only 450,000 years. But in 2020, a paper published in the International Journal of Earth, Climate and Life Interactions reported that analysis of stalagmites collected from caves in southern Arabia — Yemen and northern Oman — had pushed the record back 1.1 million years.

In that time, analysis of the stalagmites revealed there had been no fewer than 21 “pluvial periods” — periods of increased rainfall, creating “numerous opportunities” for early humans to migrate out of Africa and into Eurasia, unimpeded by the more typical periods of arid weather and desert conditions that otherwise acted as barriers to early human dispersal.

But, as the authors of the latest research report in Nature said, “although numerous humid phases occurred in southern Arabia during the past 1.1 million years, little is known about Arabia’s paleoclimate before this time.”

The new research has now pushed back the region’s hydroclimate record a further 7 million years, in the process revealing much earlier “recurrent humid periods characterized by increased water availability and vegetation cover.”

The caves selected for the study, located in the Al-Sulb Plateau, northeast of Riyadh, had been identified by the Saudi Geological Survey.




The Saudi Geological Survey (SGS) says there are over 150 caves recognized for their remarkable scientific significance in Saudi Arabia. (SPA)

“What drew us to this site was the fact that the modern landscape there is hyper arid, yet in the caves we see lots of evidence of stalactite and stalagmite growth,” said Markowska. “This means that it was wetter in the past because these just don’t form under the modern conditions.”

For “conservation reasons,” the paper gives only the general locations of the caves. However, the precise coordinates are available to some professional organizations and researchers from the Saudi Heritage Commission and the Saudi Geological Survey.

The story told by the 22 speleothems collected from the seven cave systems, all found within a 10 km radius, is an extraordinary one. Analysis of the samples has revealed a series of humid episodes over four distinct periods — between 0.86 and 1.37 million years ago (Ma), 2.01 and 2.29 Ma, 3.16 and 4.10 Ma, and 6.25 and 7.44 Ma.

This last humid episode occurred during what geologists classify as the Late Miocene. This is the period from which numerous fossils found further south, in the UAE, date — the remains of animals such as elephants, hippopotamuses, crocodiles, antelopes, hyenas and large carnivores, including saber-toothed cats, which have been unearthed in the Western Region of the emirate of Abu Dhabi.

These animals flourished there, according to a summary of decades of research published in 2012, thanks to “a very large river system flowing slowly through the area, along which was flourishing vegetation, including large trees.”

That river system may well have flowed from the interior of Arabia — and the fresh evidence from the caves northeast of Riyadh suggests the possibility that it was rainfall here that fed it.




Monika Markowska in the lab at Northumbria University. (Supplied)

“There is evidence in Arabia of rivers in the past, and certainly in the UAE fossils have been found where a river channel once ran,” said Markowska.

“But rivers can have very distant origins and the big thing about our paper is that for the first time we were able to determine that there was rainfall specifically in the center of the desert — evidence of actual rainfall in that area, rather than humidity from rivers that were sourced from distant locations.

“Before now, we knew a little bit about what was going on in the south of Arabia, that there were numerous humid phases going back over the past 1.1 million years. But we’ve been able to push that back to 8 million years, and this is for the center of the desert, where there was really no information before.”

The importance of this discovery is highlighted by the vast well of international specialist knowledge upon which the study drew. This is reflected in the list of the paper’s 31 co-authors, who include researchers and specialists from universities in the UK, Germany, Switzerland, Australia and the US.

It also includes the College of Tourism and Archaeology at King Saud University in Riyadh, the Kingdom’s Heritage Commission, Geotourism Department and the Saudi Geological Survey.

The paper thanks Prince Badr bin Abdullah bin Farhan Al-Saud, the Saudi minister of culture, for giving his permission for the research to be carried out, and acknowledges the vital role of the Heritage Commission in providing logistical and technical field support.




Prince Badr bin Abdullah bin Farhan, culture minister of Saudi Arabia. (SPA)

So far, as the paper makes clear, the “vertebrate fossil record of Arabia is scant,” with remains found only in two principal locations: The sandstone and mudstone Baynunah Formation in the UAE and the Nefud Desert in northwestern Saudi Arabia.

The fossils in the Nefud are “only” about 500,000 years old, and 6 million years younger than those from the Baynunah Formation, currently the only site where animal remains dating from the Late Miocene have been found.

But, said Markowska, the lack of fossil evidence from the same period in central Arabia “doesn’t necessarily mean there wasn’t fauna there at that time, but only that we haven’t found them yet.”

And, as the paper concludes, “considering our findings, it seems probable that movements between Africa and Eurasia would have taken place through the Arabian Peninsula, which, during humid phases, was likely characterized by well-watered grasslands and woodlands.”

Many of the animal species identified from fossilized remains in the UAE “would have been well suited for life in (central) Arabia during the wet episodes identified in our speleothem record. The scant fossil record aside, we suggest that Arabia probably acted as a hitherto unrecognized but important crossroad for biogeographic exchange between Africa and Eurasia over the past 8 million years.”

The researchers add that “the nature of these exchanges, and the exact role of Arabia in these, may only be elucidated with an improved fossil record.”

For now, a more pressing piece of research is underway, for the stalagmites of Saudi Arabia have more secrets to divulge.




Stunning view of Ain Heet cave, located in a mountain called Al-Jubayl in a small village in Wadi Al-Sulay, Riyadh.  Ain Heet is named after its entrance, which resembles the shape of the eye. The cave is formed with limestone. (AN file photo)

Finding out exactly what plants and trees thrived during the wet periods over the past 8 million years is key to understanding what species of herbivorous mammals — and, therefore, the meat-eaters that preyed upon them — might have existed in the once greener, lusher Saudi Arabia.

“This vegetation issue is our big next research question,” said Markowska.

“We have been able to identify these humid periods, and to identify what the dominant mechanisms for causing them were — basically, more moisture coming up from the south, during monsoon seasons. But we’re also very interested in this vegetation story.”

As speleothems grow, “they trap tiny amounts of pollen within their structure, and now we’re going to see if we can extract some ancient pollen from the speleothems, which is a technique we specialize in at Northumbria.”

This is a painstaking effort, “which involves a lot of microscope work. You extract the material, put it on a microscope slide and then count and identify the different pollen grains you find. I work with other colleagues who are experts on (ancient) pollen, and together I think we should be able to unwrap this other side of the story.”
 

 


Saudi defense minister, Yemen PM discuss relations 

Saudi defense minister, Yemen PM discuss relations 
Updated 06 May 2025
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Saudi defense minister, Yemen PM discuss relations 

Saudi defense minister, Yemen PM discuss relations 

RIYADH: Prince Khalid bin Salman, Saudi minister of defense, met with Yemen’s newly-appointed Prime Minster Salem Saleh Bin Braik.

The pair discussed ways to boost Saudi-Yemeni relations, in addition to regional developments and the situation in Yemen. 

”I reaffirmed the Kingdom’s continued support for the government of Yemen in ways that will meet the aspirations of the Yemeni people,” Prince Khalid said in a post on X.

He also conveyed the Saudi leadership’s best wishes to Bin Braik after his appointment as Prime Minister, as well as their hopes for his success and for the stability, security, and prosperity of the people of Yemen. 

Yemen’s internationally recognized government named finance minister Bin Braik as its new prime minister on Saturday.


UNESCO delegation visits North Riyadh Geopark after global network listing

UNESCO delegation visits North Riyadh Geopark after global network listing
Updated 05 May 2025
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UNESCO delegation visits North Riyadh Geopark after global network listing

UNESCO delegation visits North Riyadh Geopark after global network listing
  • Destination showcases Kingdom’s natural and cultural diversity, UNESCO official says
  • In April, UNESCO listed North Riyadh Geopark and Salma as part of its Global Geoparks Network

RIYADH: UNESCO’s Assistant Director-General for Natural Sciences, Lidia Brito, visited North Riyadh Geopark on Sunday, praising the destination for preserving both nature and history.

The UN Educational, Scientific, and Cultural Organization designated North Riyadh Geopark in April as part of its Global Geoparks Network, which aims to protect geological heritage sites and promote sustainable development.

Hussam Zuhair Al-Turki, director of the Saudi Geoparks Initiative, and Hamoud Alnughaymishi, director of the Science Sector at the Saudi National Commission for Education, Culture, and Science, accompanied Brito during her visit.

They explored significant geological features at the North Riyadh Geopark, including the Abu Shaddad Cave and the Edge of the World cliff. They also stopped to explore Ghamra Village, known for its natural adventure routes on the outskirts of Riyadh.

Brito said that the North Riyadh Geopark showcases the natural and cultural diversity of Saudi Arabia, and will enhance eco-tourism in the Kingdom, the Saudi Press Agency reported.

In April, UNESCO designated North Riyadh Geopark and Salma Geopark as part of its Global Geoparks Network. The Kingdom hopes to register 13 other sites on UNESCO’s network, the SPA added.


Riyadh’s latest group game spot encourages social connection

Pixel Games adds to the Kingdom’s capital’s growing roster of homegrown gaming concepts. (Supplied)
Pixel Games adds to the Kingdom’s capital’s growing roster of homegrown gaming concepts. (Supplied)
Updated 05 May 2025
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Riyadh’s latest group game spot encourages social connection

Pixel Games adds to the Kingdom’s capital’s growing roster of homegrown gaming concepts. (Supplied)
  • Center designed to engage people physically, mentally

RIYADH: As Saudi Arabia encourages more active and social lifestyles, a group of young Saudi entrepreneurs in Riyadh has created a space that blends movement, mental challenges, and social connection.

Opened in 2024, Pixel Games is a locally developed gaming center designed to engage people both physically and mentally. It is also a testament to the vision and drive of young Saudis, who are shaping the Kingdom’s entertainment landscape.

Pixel Games adds to Saudi Arabia’s capital’s growing roster of homegrown gaming concepts. (Supplied)

Riyadh has no shortage of entertainment options, and Pixel Games adds to the city’s growing roster of homegrown concepts.

While the founders would like to keep a low profile, they are working behind the scenes to address the local appetite for interactive social spaces that go beyond traditional arcades or seasonal pop-ups.

FASTFACTS

• Activities at Pixel Games range from strategic puzzles to movement-based games, all designed for groups of friends and families to enjoy together.

• Each session lasts an hour, and visitors can reserve private rooms for a more personal experience.

The center features nine themed “moving rooms,” with more than 40 group-based physical and mental challenges.

Riyadh has no shortage of entertainment options, and Pixel Games adds to the city’s growing roster of homegrown concepts. (Supplied)

Activities range from strategic puzzles to movement-based games, all designed for groups of friends and families to enjoy together. Each session lasts an hour, and visitors can reserve private rooms for a more personal experience.

Visitors have responded positively to the experience. Nawaf Aloggayel, a recent guest, said: “The place is beautiful, the games are different and fun, and the prices are reasonable.

Pixel Games adds to Saudi Arabia’s capital’s growing roster of homegrown gaming concepts. (Supplied)

“I advise people to come … it’s the best entertainment place in Riyadh so far.”

Ahmed Al-Ahmed, marketing representative for Pixel Games, said: “Pixels is an entertainment center that gathers challenges and fun into a group of different movement activities.

“Groups can enjoy a private room, which makes it more exciting and comfortable.”

What sets it apart is its year-round availability, making it a go-to spot for spontaneous plans or scheduled outings. It provides a safe and stimulating environment where children can burn off energy, develop problem-solving skills, and socialize with their peers.

Whether you are looking for a quick group activity, a family outing, or a way to try something new with friends, Pixels offers a low-key alternative for playful competition and connection.

 


Biotech program to empower Saudi innovators

General view in Riyadh, Saudi Arabia. (REUTERS)
General view in Riyadh, Saudi Arabia. (REUTERS)
Updated 05 May 2025
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Biotech program to empower Saudi innovators

General view in Riyadh, Saudi Arabia. (REUTERS)
  • The seven-month program offers participants mentorship, capacity development, and networking opportunities with local and international investors and experts

RIYADH: The Ministry of Health has launched a biotechnology accelerator program to empower Saudi innovators in biotechnology and life sciences.

The initiative aims to enhance their scientific and commercial readiness, attract investment, and expand their global market reach, the Saudi Press Agency reported.

It also seeks to boost their contributions to healthcare quality, aligning with the National Biotechnology Strategy and the Health Sector Transformation Program under Vision 2030, which envisions a thriving, innovation-driven economy and a vibrant society with sustainable health and quality of life.

The seven-month program offers participants mentorship, capacity development, and networking opportunities with local and international investors and experts.

It includes workshops, seminars, individual consultations, and a chance to present innovations at the BIO 2025 Conference.

The application deadline is May 8. Interviews and initial selection will take place from May 15-20, with final acceptances announced on May 25.

The ministry continues to advance health innovation and accelerate the progress of promising national projects. It encourages all Saudi innovators, entrepreneurs, and startups to register for the program and inquire via [email protected]

 


Insan spends SR55m on beneficiary families in first quarter of 2025

The society deposited SR27.6 million into families’ bank accounts for basic expenses (cash, clothing, and food). (X @ensanorg)
The society deposited SR27.6 million into families’ bank accounts for basic expenses (cash, clothing, and food). (X @ensanorg)
Updated 05 May 2025
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Insan spends SR55m on beneficiary families in first quarter of 2025

The society deposited SR27.6 million into families’ bank accounts for basic expenses (cash, clothing, and food). (X @ensanorg)
  • Programs aim to meet needs through seasonal initiatives, monthly services, direct assistance

RIYADH: The Charitable Society for Orphans Care in Riyadh, also known as Insan, implemented several programs during the first quarter of 2025 aimed at meeting the needs of families through seasonal initiatives, monthly services, and direct assistance.

Total expenditure on services and initiatives provided during the first quarter amounted to SR55.09 million ($14.66 million), which included basic, seasonal, and other services.

The society deposited SR27.6 million into families’ bank accounts for basic expenses (cash, clothing, and food).

It also deposited SR2,790,600 for the Ramadan Basket Project, benefiting 9,251 families to meet their needs during the holy month of Ramadan, and SR1,060,800 for the Eid Gift Project, helping 5,304 through special gifts during Eid Al-Fitr.

There were more than 21,000 beneficiaries from the Zakat Al-Fitr project during the first quarter, covering their food needs before Eid Al-Fitr, at a cost of SR3.86 million.

The quarterly report issued by Insan highlighted the numerous programs and activities provided by it, including Imaniyat, Pioneers of the Future, Be a Human Compass, Mualham, and Medad.

These programs included developmental and empowerment paths, helping 2,853 beneficiaries.

In line with its commitment to meeting the needs of beneficiary families, Insan provided 7,725 diverse services during the first quarter, including emergency assistance, social and health support, bill payments, housing expenses, furnishing and maintenance, contributions to home purchases, healthcare, and other services. The society spent SR19,773,339 on these services.

It also conducted 1,469 visits to families in the first quarter. These assessed conditions, listened to needs, and identified requirements. The family satisfaction rate reached 93 percent.

In an effort to empower beneficiaries in various fields, the society conducted 436 applications for training, diploma, bachelor’s degree, employment, and project financing.