New research reveals industrial waste can turn into rock in as little as 35 years, instead of the thousands or millions of years previously assumed. The finding challenges what scientists know about rock formation, revealing an entirely new “anthropoclastic rock cycle.” The scientists found that waste from seaside industrial plants turns into rock especially rapidly due to the ocean water and air, which activate minerals such as calcium and magnesium in the waste, or slag, cementing it together faster than natural sediments.
For a couple of hundred years, we’ve understood the rock cycle as a natural process that takes thousands to millions of years but these human-made materials are being incorporated into natural systems and becoming lithified — essentially turning into rock — over the course of decades instead. Researchers dubbed this newly discovered process the “rapid anthropoclastic rock cycle.” The findings challenge long-standing theories about how rocks form and suggest industries have far less time to dispose of their waste properly than previously thought, Owen said in the statement. The research was published April 10 in the journal Geology.
Researchers discovered the first clues of turbo slag-to-rock transformation on Derwent Howe, a giant pile of waste from now-closed iron and steelmaking plants on the northwest coast of England. The scientists noticed irregular formations in these slag “cliffs,” prompting them to take a closer look. One sample contained an aluminum can tab, with a design that couldn’t have been manufactured before 1989, embedded in the material that helped the researchers estimate how long it takes for slag to lithify. For the can tab to become encased in rock, the slag must have solidified and lithified in the past 35 years. It’s possible that these processes finished earlier, so 35 years is the maximum time it takes to turn slag into rock. Scientists have previously made similar observations on the coast of Spain in the Gorrondatxe area, the researchers noted in the study, but those observations didn’t come with a time frame.
Excerpted from a LiveScience article by Sascha Pare