Plastiglomerates: A New Kind of Rock

Between the durability and flexibility of plastics, it is no surprise that their production has increased substantially from decade to decade from its initial invention. These plastic products act as both a blessing and a curse for civilization however, as they can potentially irreversibly alter the composition of the Earth’s future stratigraphy. Some of the very things plastics are most valued for, durability and resistance to deterioration, are what make them such a large potential influence on the foreseeable geological timescale. While plastics by themselves have a chance to be buried under sediment, they also have a decent chance of being transported before having the chance to be buried or float on top of or within a water column rather than sinking to the bottom. This changes however with the introduction of plastiglomerates. Plastiglomerates, a newly discovered “rock type,” are a conglomeration of sand, volcanic ash, woody debris, and other materials within a molten plastic matrix. This adhesion of several materials to the plastic causes an increase in density and can sequentially lead to an increased likelihood of burial due to a resistance to transport and a preference to sink in the water column compared to plastics, whether micro or macro, by themselves. With the discovery of these plastiglomerates, the question of just how these plastics will be preserved rises. This paper will explore the possibilities of said preservation and explore how it may look in the future geological record.