Plastiglomerate

Plastiglomerate is a rock made of a mixture of sedimentary grains, and other natural debris (e.g. shells, wood) that is held together by plastic.

[1] It has been considered a potential marker of the Anthropocene, an informal epoch of the Quaternary proposed by some social scientists, environmentalists, and geologists.

[7] 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".

Plastiglomerate is denser than particles that are solely composed of plastic, which gives them greater potential to become buried and preserved in the rock record.

[2] Approximately one-fifth of the plastiglomerates found at Kamilo Beach of fishing debris, one quarter of broken lid containers, and one half consisted of plastic "confetti".

The melting of plastic waste from campfires or high temperatures on beaches (1) is resulting in the formation of a new type of rock known as plastiglomerate (2). Formed plastiglomerate merges with surrounding sediment to create a compositionally different sediment layer (3).The emergence of this new layer is being used as physical evidence of a marker horizon for an Anthropocene Epoch (4).
Plastiglomerate from Kamilo Beach displayed in the exhibition One Planet in Museon (The Hague, The Netherlands).