A large island off the coast of Brazil, now lying at the bottom of the Atlantic Ocean, may contain vast reserves of rare earth elements and other valuable minerals. Known as the 'Rio Grande Rise', the submerged continental plateau formed as a volcanic ridge about 40 million years ago and was once a large tropical landscape covered in vegetation.
The 'Rio Grande Rise' is located 1,200 kilometers off the Brazilian coast and covers about 150,000 square kilometers of sea floor at depths ranging from 700 to 2,000 meters. But why is it considered an 'island'?
In a study published in the journal 'Scientific Reports', scientists revealed that new analysis of soil excavated from the platform – evaluating the mineral, geochemical and magnetic properties of the sediment – confirms that the mountain range is an island. Composed mainly of red clay, it corresponds to the characteristic 'red earth' found in many parts of the state of São Paulo.
The elements found that the clay formed as a result of intense chemical weathering of volcanic rocks in a hot and humid climate, along with active volcanism – led the researchers to conclude that the site lasted for 35 years during the Eocene. million years ago, and characterized by tropical conditions.
“Our investigation and analysis allowed us to determine that it is indeed an island,” study author Luigi Jovan pointed out in a statement. “Geologically speaking, we found that the clay was formed after the last volcanic activity that occurred 45 million years ago. So, the formation dates back between 30 and 40 million years and under these tropical conditions,” he added.
But the island is more than a destination for scientific studies: it promises to become a much-loved destination. Why? Because it is rich in valuable minerals such as cobalt, lithium and nickel, as well as high-value rare earth elements such as tellurium, it has sparked great interest in extracting natural resources.
The problem is that the site is located in international waters, which is why it is 'governed' by the International Maritime Organization. The Brazilian government has already requested that its continental shelf be legally extended to include the 'island'. However, this is unlikely to be ratified as the United Nations Convention on the Law of the Sea (UNCLOS) states that a country cannot hold maritime territory more than 200 nautical miles off its coast.
“We need to analyze the sustainability and impacts of this extraction to find out if we can extract resources from the seabed in a viable way”, Jovan revealed. “When you intervene in an area, you need to know how it will affect animals, bottoms and corals, and understand the impact it has on the overall processes involved,” the researcher concluded.