NASA’s Curiosity rover has offered evidence that Mars once had a continental crust that was surprisingly similar to Earth’s granitic continental crust rocks. Using its ChemCam laser instrument, Curiosity collected data about Martian rocks and beamed them back. A team of scientists from the U.S. and France analyzed 20 rocks and published findings of their study in the journal Nature GeoScience.
Scientists find something unexpected on Mars
Roger Wiens of Los Alamos National Laboratory and the lead author of the study said they saw some beautiful rocks with bright, large crystals – something that was unexpected on Mars. Scientists were expecting the rocks to reveal large samples of basalt. But these rocks were rich in silica, which indicates that Mars had a different geological history than previously believed.
Wiens said the red planet’s geological history was pretty much like that of our own planet. The light colored rocks crystals are lower in density, and are “abundant in igneous rocks that make up the Earth’s continents.” The newly studied rocks were sourced from Gale Crater, which features varying concentrations of alkaline compositions. These rocks are estimated to be 3.6 billion years old.
Mars had a more dynamic geologic history than thought
After analyzing images and chemical results of these rock fragments, researchers concluded that silica-rich magmatic rocks may constitute a huge portion of the ancient Martian crust. They may be analogous to the early continental crust on Earth. Until now, the scientific community believed that Mars had little magmatic activity. That’s why Roger Wiens and his team were expecting to see large expanses of basalt.
The silica-rich rocks point to a more dynamic magmatic and geologic history that includes crusts and plate tectonics. Researchers said they haven’t yet found a direct evidence of plate tectonics on Mars, but “there’s a bit of evidence for the precursor to tectonics.” Magnetic domains have been found in parts of the southern hemisphere of Mars. The red planet lacks a magnetic field now, but it did have one in the past, said Wiens.