[A] new type of rock cobbled together from plastic, volcanic rock, beach sand, seashells, and corals has begun forming on the shores of Hawaii.

These stones, which they’ve dubbed “plastiglomerates,” most likely formed from melting plastic in fires lit by humans who were camping or fishing. When the plastic melts, it cements rock fragments, sand, and shell debris together, or the plastic can flow into larger rocks and fill in cracks and bubbles to form a kind of junkyard Frankenstein.

The mass of plastic produced since 1950 is close to 6 billion metric tons, enough to bundle the entire planet in plastic wrap. Combine plastic’s abundance with its persistence in the environment, and there’s a good chance it’ll get into the fossil record, Zalasiewicz says. “Plastics, including plastiglomerates, would be one of the key markers by which people could recognize the beginning of the Anthropocene”.

By Angus Chen via Science Mag.