NASA’s Curiosity rover has provided evidence of Mars’ primitive continental crust using ChemCam laser instrument, which showed that the rocks were surprisingly similar to Earth’s granitic continental crust rocks.
Roger Wiens of Los Alamos National Laboratory, lead scientist on the ChemCam instrument said that they saw some beautiful rocks with large, bright crystals, quite unexpected on Mars. As a general rule, light-colored crystals have lower density, and are abundant in igneous rocks that make up the Earth’s continents.
This is the first discovery of a potential “continental crust” on Mars.
French and US scientists observed images and chemical results of 22 of these rock fragments.
According to the paper’s first author, Violaine Sautter, these primitive Martian crustal components bear a strong resemblance to a terrestrial rock type known to geologists as TTG (Tonalite-Trondhjemite-Granodiorite), rocks that predominated in the terrestrial continental crust in the Archean era (more than 2.5 billion years ago).
Gale crater, excavated about 3.6 billion years ago into rocks of greater age, provided a window into the Red Planet’s primitive crust. The crater walls provided a natural geological cut-away view 1-2 miles down into the crust.