Crust of Mars
According to a team headed by Dr Violaine Sautter from the National Museum of Natural History in Paris, France, similar to early Earth’s, Mars had a continental crust. That is the finding of a new paper published in Nature Geoscience.
NASA’s Curiosity rover has turned its beam onto some unusually light-colored rocks on Mars. The results are surprisingly similar to Earth’s granitic continental crust rocks. Martian crustal components bear a strong resemblance to tonalite-trondhjemite-granodiorites. This type of rocks predominated in Earth’s continental crust more than 2.5 billion years ago. This is the first discovery of a potential “continental crust” on Mars.
Analysis of those rocks found that they were made in spar. They’re like terrestrial rocks found in Earth’s continental crust concerning 2.5 billion years past. The rocks square measure terribly completely different from the dark and dense volcanic rock that frame alternative parts of Mars’ surface. Combined with earlier proof of a wet young Mars, it appears the planet’s history is a lot of like Earth’s than we tend to originally thought. What is interesting about this exploration is that it could only be done on site. This is why we send probes and rovers to other worlds. Sometimes just looking from a distance isn’t enough.
Dr Roger Wiens of Los Alamos National Laboratory, said that “Mars has been viewed as an almost entirely basaltic planet, with igneous rocks that are dark and relatively dense, similar to those forming the Earth’s oceanic crust. Gale Crater, the place where NASA’s Curiosity rover landed, contains fragments of very ancient igneous rocks (3.6 billion years old) that are distinctly light in color, that were analyzed by the rover’s ChemCam instrument.”
Dr Wiens, Dr Sautter and their colleagues from the United States, UK and France observed chemical results and images of 22 of these rock fragments.
The team determined that these pale rocks are unexpectedly similar to Earth’s granitic continental crust because they are rich in feldspar, possibly with some quartz.
The scientists wrote in a paper published in the journal Nature Geoscience: “We present geochemical data and images of 22 specimens analyzed by Curiosity that demonstrate that these light-toned materials are feldspar-rich magmatic rocks.”
These rocks belong to 2 distinct types: alkaline compositions containing up to 67 percent SiO2 and 14 percent total alkalis (Na2O+K2O), with fine-grained to porphyritic textures on the one hand, and coarser-grained textures consistent with quartz diorite and granodiorite on the other hand.
In other paper published in the same journal, the scientists wrote: “Combined with the identification of feldspar-rich rocks elsewhere and the low average density of the crust in the Martian southern hemisphere, we tend to conclude that silica-rich magmatic rocks may represent a significant fraction of ancient Martian crust and may be analogous to the earliest continental crust on Earth”.