NASA researchers have been looking into the analyses of rock samples taken from the Gale Crater on Mars. The samples relate to sol 1060 (a term applied to the number of Martian days passed since the rover landed), Curiosity drilled into some rock in a location termed Buckskin. These rocks have produced some interesting findings.
The rock samples were subject to X-ray diffraction study in order to reveal the mineral content. This examination showed high quantities of a silica mineral called tridymite. This mineral is unusual and it is typically associated with silicic volcanism. Scientist Bob Hill (@bobhillbrain) tweeted: “#NASA Finds Tridymite, a “Completely Unexpected” Mineral, on Mars…a surprises box.”
Silicic volcanism is something not previously associated with the red planet. It is, however, common to Earth. On Earth, silicic volcanic rocks have long been recognized as being associated with continental flood basalt provinces. These are produced by high temperatures and pressure. Tridymite is a high-temperature polymorph of silica.
The discovery of tridymite will now re-shape the some of the theories relating to Mars, including a supposed lack of volcanic activity. Commenting further, Dr. Richard Morris of NASA stated: “The tridymite was incorporated into ‘Lake Gale’ mudstone at Buckskin as sediment from erosion of silicic volcanic rocks… The combination of high silica content and extremely high temperatures in the volcanoes creates tridymite.”
It could be that Mars was subjected to a much more violent and explosive volcanic history during the early evolution of the planet than previously thought. This is puzzling because Mars does not have plates that shift and collide like those on Earth, which leads to volatile volcanoes and earthquakes. It follows that the findings will also stimulate scientists to re-examine the way tridymite forms.
The findings were analysed at the NASA Astromaterials Research and Exploration Science (ARES) and the findings are published in the journal Proceedings of the National Academy of Sciences. The paper is titled: “Silicic volcanism on Mars evidenced by tridymite in high-SiO2 sedimentary rock at Gale crater.”