As an astronomer, I’m used to seeing our universe has hydrogen, helium, and everything else, where I’m absolutely willing to refer to everything else as a metal. Today’s news is challenging this way of seeing things, and forcing me to consider the chemistry behind all the different ices and rocks that make up our world and others. 

Here on Earth, as we’ll be discussing more in the context of Iceland later in the show, we can learn about our world’s history and internal structure from what we can find around volcanoes and coming out of their fissures and calderas. One of the most fascinating places to explore is the ocean floor. 

In new research in the Pacific Ocean, a team from Leeds’ Institute of Geophysics and Tectonics has obtained new samples by sending their equipment six kilometers down to the floor of the ocean and then drilling a further 1.5 kilometers. The site of their drilling was along the Pacific Ring of Fire, a region that has been geologically active for at least 50 million years. Their particular drill site was off the coast of Japan, and according to researcher Ivan Savov: This was one of the deepest waters ever to be considered for drilling, using a research vessel specifically designed for such challenging deep-sea environments.

When lava cools into a solid, that solid is called basalt, and Savov goes on to say: Basalt is among the most common types of rock on earth. We were looking for basalt that was formed during early Ring of Fire volcanic eruptions.

They found the basalt, and they found it was like nothing ever before seen, with a unique chemical and mineral makeup that indicates early eruptions were both more powerful and more voluminous than previously thought. Savov adds: Now that we know where and how this rock type is formed, we anticipate that many other rocks that we know were originally formed by ocean floor eruptions will be re-examined and potentially alter our wider understanding of the basalt formation.

There are two places humans are only beginning to explore: the bottom of the ocean and outer space. Let’s face it, planets like to hide their secrets, and our Earth is counted among that secretive crew.

More Information

EurekaAlert press release

“Basalt derived from highly refractory mantle sources during early Izu-Bonin-Mariana arc development,” He Li et al., 2021 March 19, Nature Communications