A huge ancient volcano has brought a rare mineral to Martian Gale Crater

The mysterious discovery of a chunk rich in the rare mineral quartz in Mars' Gale Crater by the Curiosity rover in 2016 has finally been explained by researchers.

A team of planetary scientists from Rice University, NASA's Johnson Space Center, and the California Institute of Technology (CalTech) believe that the tridymite-rich chunk was ejected by a volcano about 1 billion years ago, when Gale Crater was still full of water. It is.

This new scenario, published in the journal Earth and Planetary Science Letters, shows that the Red Planet has a more interesting and complex volcanic history than previously thought. It would, yes.

Tridymite, which is very rare on Earth, is a type of quartz (a form of silica) that forms at extreme temperatures and low pressure, and how it entered the ancient lake bed. It had occupied researchers for many years.

Kirsten Siebach, a professor at Rice University and a member of the research team Fatt: "The discovery of tridymite in a mudstone in Gale Crater is one of the most amazing observations that the Curiosity rover has made in 10 years of exploring the Red Planet." He added: "Tridymite is usually associated with quartz-forming volcanic systems, explosive and Volcanism is involved, but we found it at the bottom of an ancient lake on Mars, where most of the early volcanoes would have been.

To solve this puzzle, Seebach and his colleagues looked at data on the formation of tridymite on Earth. . They also considered models of a volcano on the Red Planet, its volcanic material, and sediment signatures collected from Gale Crater from Curiosity's landing site in August 2012.

Thus, they managed to design a new scenario that shows Martian magma has been sitting in a reservoir beneath the volcano for a longer period of time than usual, causing it to cool at least partially and increase the silicon concentration of the magma through a process called partial crystallization.

Then a massive eruption, material containing This released excess silicon into the lake in the form of tridymite, which eventually found its way into the Gale Crater as well as the surrounding rivers. This volcanic material was then broken down by the water in the ancient lake and the minerals in it were separated. Opaline and reducing the concentration of aluminum oxide also help.

Aerial view of Gale Crater
Credit: NASA/JPL-Caltech/ASU/UA

"This is actually a direct evolution of other volcanic rocks that we found in the crater," Seebach said. . Because we only saw this mineral once and it was in a very rich layer, the volcano probably erupted at the same time as the lake was there. Although the particular sample examined was not just volcanic material and ash, it was also material that had been affected by weathering.

These findings also have broader implications for the geological history of Mars. This means that the red planet must have undergone a violent and explosive volcanism more than 3 billion years ago. when Mars was changing from a warm, wet world to the dry, barren planet it is today.

"There is abundant evidence of basaltic volcanic eruptions on Mars, but this study shows a more evolved chemistry," Siebach noted. and suggests that Mars may have a more complex and fascinating volcanic history than we thought before Curiosity. It reached strange rocky branches

Cover photo: Curiosity rover in Gale Crater
Credit: NASA, JPL-Caltech and MSSS

Source: Space