Plastiglomerate

Plastiglomerate is a term that was proposed by Patricia Corcoran, Charles Moore and Kelly Jazvac for a stone that contains mixtures of sedimentary grains, and other natural debris (e.g. shells, wood) that is held together by hardened molten plastic. It has been considered a potential marker of the Anthropocene, an informal epoch of the Quaternary proposed by some social scientists, environmentalists, and geologists.

Plastiglomerates form along shorelines where natural sedimentary grains and organic debris are agglutinated by melted plastic created during campfire burning. They have been reported from Kamilo Beach on the island of Hawaii.

Plastiglomerate could potentially form a marker horizon of human pollution on the geologic record. and may survive as future fossils. Plastiglomerate may also conceivably form in plastic-polluted regions affected by lava flows or forest fires. They have been found on the surface as well as beneath the sand. This suggests that plastiglomerates are being actively deposited into the sedimentary record. Some geophysicists and geologists speculate that plastiglomerates will not persist in the fossil record, however, or that they might "revert back to a source of oil from whence they came, given the right conditions of burial".

"In situ" plastiglomerate forms where plastic melts and fills in rock cavities. "Clastic" plastiglomerate are smaller solitary pieces that form where larger fused items become fragmented by waves. Plastiglomerate is more dense than particles that are solely composed of plastic, which gives them greater potential to become buried and preserved in the rock record.

Plastiglomerates have been featured at the Yale Peabody Museum of Natural History; Oakville Galleries in Oakville, Ontario, Canada; Louis B. James Gallery in New York City; Carleton University Gallery in Ottawa, Ontario, Canada; Prosjektrom Normanns, Stavanger, Norway; and Museon in The Hague, Netherlands

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