A new study has revealed that a rock formed from industrial waste can develop in just a few decades, challenging long-standing ideas that rock formation takes thousands or even millions of years.
Researchers in the United Kingdom have identified a new geological process in which materials from old industrial sites, particularly along coastlines, transform into solid rock within approximately 35 years.
The discovery not only introduces a new type of human-influenced rock cycle but also raises fresh concerns about how quickly industrial waste becomes embedded in the Earth’s geological record.
The research focused on Derwent Howe, a large mound of slag waste left over from iron and steel production on England’s northwest coast. Scientists observed unusual shapes in the slag cliffs, prompting further investigation into how these formations had developed so rapidly.
Coastal conditions speed up waste-to-rock transformation
The findings, published April 10 in the journal Geology, show that coastal conditions, especially exposure to ocean water and air, accelerate the hardening process.
These natural forces react with minerals commonly found in slag, such as calcium, iron, magnesium, and manganese. The interaction helps create natural cement-like materials that bind particles together, accelerating the transformation from loose waste to solid rock.
“For a couple of hundred years, we’ve understood the rock cycle as a natural process that takes thousands to millions of years,” said Amanda Owen, senior lecturer in sedimentology at the University of Glasgow and lead author of the study.
Evidence from coins and cans narrows the timeline
To study the process in detail, the team collected samples from 13 different locations across the site. They used specialized tools to analyze the chemical composition of the slag.
One particular sample included both a King George V coin from 1934 and a can tab with a design that could not have existed before 1989. These findings helped researchers estimate the timeline of the rock’s formation.
John MacDonald, a senior lecturer in anthropogenic geomaterials and co-author of the study, said the presence of the can tab shows the rock formed sometime within the past 35 years.
The team has named this new process the “rapid anthropoclastic rock cycle.” Similar signs have been spotted along other coastlines, including in Spain’s Gorrondatxe area. However, those cases lacked a confirmed timeframe.
“I think it’s very likely that this same phenomenon is happening at any similar slag deposit along a relatively exposed coastline with some wave action,” said David Brown, a co-author and volcanology expert at the University of Glasgow.
As scientists continue to study the impacts of human activity on the planet’s geology, this rock formed from industrial waste adds a new chapter—one that’s developing much faster than expected.