The sunken island off the coast of Brazil is filled with rare earths

A giant ancient island now located at the bottom of the Atlantic Ocean may contain huge reserves of rare earth elements and many other valuable minerals.

Named the Rio Grande Rise (RGR) , the submerged continental plateau formed as a volcanic ridge about 40 million years ago and was once a vast tropical land covered with vegetation. An international research team led by Priyeshu Srivastava at the University of Sao Paulo announced their findings in the journal Nature, IFL Science reported on March 17.

Rio Grande Rise Island is located about 2,000 meters below the water's surface. (Photo: IO-USP).

Located 1,20km off the coast of Brazil, RGR covers about 150,000km2 ^of seabed at depths from 700 to 2,000m. The hypothesis that the volcanic ridge may have been an island first emerged in 2018 and has now been confirmed by analysis of soil samples dredged from the western RGR.

Evaluating the mineral, geochemical and magnetic characteristics of the sediment, the research team discovered that the sample was mainly composed of red clay consistent with the typical type of "red soil" (terra roxa) found. in many places in Sao Paulo state. In the soil, the researchers identified many minerals commonly found in volcanic rock variants, including oxidized magnetite, hematite, goethite, and kaolinite.

The findings reveal that clay forms as a result of the weathering of volcanic rocks in warm, wet weather. Based on the analysis, the team concluded that RGR accumulated rare earth elements during the Pleistocene, which lasted until about 35 million years ago and was characterized by tropical conditions.

Previous research has also revealed that the submerged island is rich in valuable minerals such as cobalt, lithium, and nickel, along with valuable rare earth elements such as tellurium. Because these materials are key components in a range of new technologies that help stop the burning of fossil fuels, the exploitation of natural resources in RGR attracts much interest.

Located in international waters, RGR is currently managed by the International Seabed Authority , although the Brazilian government has applied to extend its continental shelf to the island. In reality, the application is unlikely to go through because the United Nations Convention on the Law of the Sea (UNCLOS) stipulates that a country cannot own more than 370.4km beyond its coastline.