If you’ve ever studied geography, looked at fossils in a museum, or even looked up at a craggy cliffside or a steep mountain, you’ll know that rocks usually take millions of years to form.

However, according to new research from the University of Glasgow in Scotland, this may no longer be the case.

And that’s not good news – especially since our human impacts on our planet and its environment are to blame.

There are three rock types: igneous, sedimentary, and metamorphic. The first type, igneous, is a kind of rock that is formed when lava cools, so is the fastest forming type of rock, occurring on the surface of our planet after a volcano erupts, as well as under the surface too.

Sedimentary rock is comprised of sediment, as the name suggests. Over time, tiny minerals, sand, rocks, and debris layer on top of one another, with the pressure of the layers of sediment compacting it into rock.

Metamorphic rock starts off as either igneous or sedimentary rock, but because of natural (or unnatural) factors like heat, chemicals, or pressure, they turn into a different kind of rock altogether.

In the case of the second two rock types, this all takes a whole lot of time. So you may not believe it when you read that a team of researchers have discovered in Cumbria, England, rock that is forming in just 35 years.

That’s according to their study, which was recently published in the journal Geology.

Their paper details a new phenomenon known as the ‘rapid anthropoclastic rock cycle,’ which means that material and debris from humans is accelerating the formation of rocks in a process that is not unlike the aforementioned natural rock cycles.

Taking place at industrial sites, the rock is forming as an effect of slag, the waste product of the steel industry, comprising mixed waste metal by-products.

And the thing that tipped them off – the presence of coins and ring-pulls from soda cans – really shows just how detrimental our effect on our planet is.

After noticing strange cliff formations on the English coastline, the University of Glasgow team used a variety of methods – electron microscopy, X-ray diffraction, and Raman spectroscopy – to gain a thorough understanding of the composition of these deposits, which are being eroded by the ocean’s waves.

The chemical make-up of the cliffs was telling: the calcium, iron, manganese and magnesium, all chemical elements that are typical of slag, are accelerating the formation of rocks as they are being eroded by the sea, causing a million-year process to speed up significantly.

Just how much it was accelerating was demonstrated by some tell-tale signs, as the University of Glasgow’s Dr Amanda Owen explained in a statement:

“What’s remarkable here is that we’ve found these human-made materials being incorporated into natural systems and becoming lithified – essentially turning into rock – over the course of decades instead. It challenges our understanding of how a rock is formed, and suggests that the waste material we’ve produced in creating the modern world is going to have an irreversible impact on our future.”

The items – a coin from 1934 and a ring-pull manufactured after 1989 – showed just how new these rock deposits were, and how concerning that fact is, as Dr John MacDonald continued:

“This gives us a maximum timeframe of 35 years for this rock formation, well within the course of a single human lifetime. This is an example in microcosm of how all the activity we’re undertaking at the Earth’s surface will eventually end up in the geological record as rock, but this process is happening with remarkable, unprecedented speed.”

Even more worryingly, this is not an isolated problem. That’s because the kind of manufacturing processes that cause these slag deposits are common all over the world, meaning that these new rock formations could be mounting higher and higher at this very moment.

Though extra rock doesn’t sound like much of an issue, it is. These aren’t natural rocks, and therefore they could have detrimental effects on both terrestrial and marine ecosystems.

As the researchers warn, this is yet another sign that we need to clean up our act, fast.

If you thought that was interesting, you might like to read about why we should be worried about the leak in the bottom of the ocean.