A new type of rock found under the ocean

An international team of researchers discovered the previously unknown type of basalt after drilling through the Pacific Ocean floor.

Basalt is a fine volcanic rock formed from rapid cooling of low viscosity lava rich in magnesium and iron (mafic lava). Magma mafic – so – called lava before it erupts on the surface – is formed by the partial melting of olivine (magnesium-iron-silicate) rocks found in the Earth’s upper surface. Basalt is home to more than 90% of volcanic rock, including large parts of the oceanic crust or volcanic islands such as Hawai’i and Iceland.

Basalt rocks often look similar, but by analyzing their chemical differences geologists can study how rocks melt and form magma inside. of the Earth. The team describes a new type of basalt formed during large and extremely hot volcanic eruptions.

The study’s co-author, Dr Ivan Savov, explains the findings: “The rocks we recovered are completely different from rocks of this type we are already familiar with. , they could be as different from the Earth ‘s ground basalts as the Earth’ s basalts to the Moon ‘s basalts. “

The recently discovered basalt differs from known rocks both in chemical and mineral production.

Its existence was previously unknown as new examples were not created in millions of years. As a result, the new type of basalt lay buried deep under sediment at the bottom of the ocean.

To find the new rock, the search team, aboard the JOIDES Search Vessel (RV), sank their drilling rig 4 miles (or 6 km) down to the ocean floor in the Amami Sankaku Basin in the Sea of ​​Japan. . They would then drill another 1.2 miles (1.5 km) into the ocean floor, producing samples that have never been studied by scientists.