Evidence of Granite on Mars Discovered in Ancient Volcano

Scientists not only have stronger evidence for granite on Mars, but also have a theory for how it could have formed there. The findings suggest that the Red Planet may just be far more geologically complex than previously believed.

Granite is an igneous rock that's common on Earth and is made up of various other types of minerals. One of them is called feldspar and was actually discovered in large quantities in an ancient Martian volcano. Minerals that are common in basalts that are rich in iron and magnesium, however, were completely absent at this location; this, in particular, is unusual since they're found almost everywhere else on Mars.

On Earth, granite (or its eruptive equivalent, rhyolite) is often found in tectonically active regions, such as subduction zones. While this is unlikely on Mars, prolonged magmatic activity on the Red Planet could potentially produce these compositions on large scales. The fact that feldspar was discovered in this ancient volcano shows that granite could indeed exist on Mars.

"We're providing the most compelling evidence to date that Mars has granite rocks," said James Wray, one of the researchers, in a news release.

In fact, these latest findings overturn the idea that Mars is a geologically simplistic planet. Scientists once believed that the planet mostly consisted of one type of rock, yet it seems that results from the Mars rover Curiosity has proved otherwise. It discovered soils with a composition similar to granite earlier this year.

"We think some of the volcanoes on Mars were sporadically active for billions of years," said Wray. "It seems plausible that in a volcano you could get enough iterations of that reprocessing that you could form something like granite."

The findings reveal a little bit more about the composition of Mars. More specifically, it shows that the Red Planet is far more complex than once believed. This new evidence reveals a geologically active area that could have possibly produced granite-a material that while common on Earth was once thought to be rare on Mars.

The findings are published in the journal Nature Geoscience.