科学美国人60秒:I Just Want to Say One Word to You: Plastiglomerate

Humanity inscribes itself into the rock record of Earth’s history. People now move more sediment than all the world’s rivers combined. Fossil fuel burning has changed the composition of the atmosphere. Everywhere are traces of the sudden appearance of rare radioactive elements like plutonium, a legacy of nuclear weapons. And now there’s even a new type of rock—that people brought into existence. 

Geologists found the novel stone on the beaches of Hawaii. Its constituents include solids of volcanic origin, sand, shells and, yes, plastic. The discoverers dubbed the material plastiglomerate. The finding is in the journal GSA Today, published by the Geological Society of America. [Patricia L. Corcoran, Charles J. Moore and Kelly Jazvac, An anthropogenic marker horizon in the future rock record]

People’s campfires on the beach inadvertently helped create plastiglomerate. Some plastic, from a soda bottle, fishing line or a plethora of other possible polymeric sources, found itself near the fire and melted. The resultant sticky goo cemented all the disparate bits together.
 
The new substance appears to be persistent, destined to stick around for a long, long time. And that's the kind of techno-fossil that may prove to be a hallmark of the Anthropocene age, this time of humanity shaping the planet.
 
—David Biello