NASA MRO Image: Strong evidence of Granite on Mars

NASA's Mars Reconnaissance Orbiter (MRO) is providing new spectral "windows" into the diversity of Martian surface materials. 

Here in a volcanic caldera, bright magenta outcrops have a distinctive feldspar-rich composition. 

Credit: NASA/JPL/JHUAPL/MSSS

Researchers now have stronger evidence of granite on Mars and a new theory for how the granite – an igneous rock common on Earth—could have formed there, according to a new study.

The findings suggest a much more geologically complex Mars than previously believed.

Large amounts of a mineral found in granite, known as feldspar, were found in an ancient Martian volcano.

Further, minerals that are common in basalts that are rich in iron and magnesium, ubiquitous on Mars, are nearly completely absent at this location.

The location of the feldspar also provides an explanation for how granite could have formed on Mars.

Granite, or its eruptive equivalent, rhyolite, is often found on Earth in tectonically active regions such as subduction zones.

This is unlikely on Mars, but the research team concluded that prolonged magmatic activity on Mars can also produce these compositions on large scales.

"We're providing the most compelling evidence to date that Mars has granitic rocks," said James Wray, an assistant professor in the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology and the study's lead author.

The research was published November 17 in the Advance Online Publication of the journal Nature Geoscience. The work was supported by the NASA Mars Data Analysis Program.

More information: J Wray, et al. "Prolonged magmatic activity on Mars inferred from the detection of felsic rocks." Nature Geoscience, 2013. http://dx.doi.org/DOI: 10.1038/NGEO1994.