Scientists have found new evidence supporting the existence of granite on Mars and have also developed a theory of how it got there, according to a new study.
Reported in a press release, the scientists said they found large amounts of feldspar, a mineral prevalent in granite, in an ancient Mars volcano. Granite is an igneous rock found commonly on Earth.
Minerals common in iron- and magnesium-rich basalts, found all over Mars, were also nearly nonexistent in those locations. The placing of the feldspar may help the researchers determine how the granite formed on Mars.
"We're providing the most compelling evidence to date that Mars has granitic rocks," said study lead author James Wray, an assistant professor in the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology.
Wray and the research team suggested a strong possibility would be extended magmatic activity on the Red Planet's surface could produce these minerals in large quantities. Mars was previously seen as being made up of one type of rock, unlike Earth, a geologically diverse planet.
NASA's Curiosity Mars rover discovered the granite-resembling rocks on the planet's surface earlier this year. The scientists conducted their study, published online Sunday in the journal Nature Geoscience, based on Curiosity's findings.
The researchers used infrared spectroscopy to study an ancient Mars volcano believed to be active for billions of years. Most of Mars' volcanoes are covered in dust, but this one was not, making it the perfect study candidate.
"Using the kind of infrared spectroscopic technique we were using, you shouldn't really be able to detect feldspar minerals, unless there's really, really a lot of feldspar and very little of the dark minerals that you get in basalt," Wray said.
The granite most likely formed on Mars after millennia of magma slowly cooling on the subsurface in a process that could take place in a volcano if it is active for a long time.
"We talk about water on Mars all the time, but the history of volcanism on Mars is another thing that we'd like to try to understand," Wray said. "What kinds of rocks have been forming over the planet's history? We thought that it was a pretty easy answer, but we're now joining the emerging chorus saying things may be a little bit more diverse on Mars, as they are on Earth."
