Researchers find ‘plastic rocks’ on island off Brazil

Subject : Science and technology

Section: Msc

Concept :

The geology of Brazil’s volcanic Trindade Island has fascinated scientists for years, but the discovery of rocks made from plastic debris in this remote turtle refuge is sparking alarm.
Melted plastic has become intertwined with rocks on the island, located 1,140 km from the southeastern state of Espirito Santo, which researchers say is evidence of humans’ growing influence over the earth’s geological cycles.
Santos’ team ran chemical tests to find out what kind of plastics are in the rocks called “plastiglomerates” because they are made of a mixture of sedimentary granules and other debris held together by plastics.
They found that the pollution coming from fishing nets is the common debris on Trinidade Island’s beaches.

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

Trindade and MartimVaz Archipelago

Trindade and MartimVaz is an archipelago located in the South Atlantic Ocean about 1,100 kilometres (680 miles) east of the coast of the Brazilian state of Espírito Santo, of which it forms a part.
The islands are of volcanic origin and have rugged terrain. They are largely barren, except for the southern part of Trindade.
They were discovered in 1502 by Portuguese explorer Estevao da Gama and stayed Portuguese until they became part of Brazil at its independence in 1822.