Our Pollution Is Creating A New Type Of Rock

“There’s a great future in plastics. Think about it. Will you think about it?” —Mr. McGuire, The Graduate (1967)

In A Nutshell

Plastics are filling our oceans at an ungodly rate. Incredibly difficult to get rid of, researchers are now finding that Mother Nature is taking some strange steps of her own. In some areas, especially those where plastic pollution is covered by sand and dirt, plastics are undergoing a change in which they are becoming compressed into the rock record, forming a new type of rock that’s being called “plastiglomerate.” It’s not known how long this plastic-rock hybrid will last, but it’s likely that should future generations ever look back on the geological rock record, they’ll see our era of pollution quite clearly.

The Whole Bushel

Plastics are a relatively new invention. They truly gained popularity in the 1950s, and it wasn’t long before we were using plastic for pretty much everything. We use it for containers and coverings, for protection from the elements, and, in most places in the United States, we still don’t think anything of it when we bring our groceries home in bags that might be around longer than we are.

Like a lot of things human beings do, we tend not to think of the long-term effects of our actions. When it comes to plastics, not only are there plenty of effects, but there are also some pretty bizarre ones.

According to the Geological Society of America, we’re creating a new type of rock.

Over the last few decades, researchers are finally taking a good, hard look at what we’re doing to the Earth with all the garbage we’re dumping into it. One of the first things they found was the impact that plastic is going to have on the Earth’s waterways.

It’s bad. We know that we’re killing marine life and ruining entire ecosystems with our garbage, but it’s only fairly recently that we’re looking at what we’re doing on the land.

Researchers from the University of Western Ontario and the Algalita Marine Research Institute have found that plastics that get buried in the ground can have a staggeringly weird impact on the makeup of the soil. They’re not decomposing or disappearing, they’re forming into a completely new type of rock.

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They’re calling it “plastiglomerate,” and there are all different kinds. It all depends on what kind of plastic the pollution was to begin with, and whether or not it’s had other forces—like heat and fire—acting on it before it got buried.

Plastics that end up in cool areas or buried under other materials might last for hundreds of thousands of years as they’re incorporated into the rock record. When we look back thousands of years right now, we can read climate changes and weather patterns in the rock records. But we’re leaving behind garbage.

Researchers looked at a couple of different places, including a beach on Hawaii that’s situated in such a way that winds and water movement mean plastics get piled up on the beaches at a staggering rate. As they do, they’re combining with the sand and sediment that’s already there, compacting to create the much denser plastiglomerate.

The beach is also a popular place for tourists, and those tourists tend to camp. Campers have campfires, and the added heat means that plastic accumulations are melting and then hardening around natural materials like wood and sand.

While it certainly isn’t too late to do something to change this unfortunate legacy, it is going to take a massive effort. In addition to cleaning up the garbage that’s already polluting our beaches, land, and waters, many countries are finding new ways to make sure that the plastic pollution doesn’t keep happening. Many European countries no longer offer shoppers the choice of getting free plastic bags for their groceries; customers have to pay for them, and that makes reusable bags a much more attractive idea.

Show Me The Proof

Geological Society of America: An anthropogenic marker horizon in the future rock record
Smithsonian Ocean Portal: Fighting Plastic From Every Angle

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