Researchers studying a remote volcanic Brazilian island, known as a refuge for green turtles, said they were startled after discovering rocks made from plastic debris strewn about the landmass. Researchers ran tests on the rocks–called “plastiglomerates”–at Trindade Island and discovered they are made of a “mixture of sedimentary granules and other debris held together by plastic,” according to a Reuters report. The plastic–believed to be derived mainly from fishing nets–washes up on the island and eventually melts, embedding itself within the island’s natural geology. “This is new and terrifying at the same time, because pollution has reached geology,” geologist Fernanda Avelar Santos from the Federal University of Parana told Reuters. “The place where we found these samples (of plastic) is a permanently preserved area in Brazil, near the place green turtles lay their eggs,” Santos said. “The pollution, the garbage in the sea and the plastic dumped incorrectly in the oceans is becoming geological material ... preserved in the earth’s geological records.”