a statement # Scholars Planetary specialists about the result #exams #mine Nader, baffled them since 2016, after it was discovered by a vehicle #curiosity in the nozzle #volcano planet #Mars.
Scientists said the mineral is tridymite, a form of quartz that forms at high heat and low pressure, and is extremely rare on Earth, but they haven’t figured out how it was found on Mars.
Scientists chose Gale Crater as a landing site for NASA’s Curiosity, due to the possibility that it contained ancient liquid water. The craft recently found evidence that Gale Crater was a lake a billion years ago.
“The discovery of tridymite in stone is a new one,” said Kristin Seebach, associate professor in the Department of Earth, Environmental and Planetary Sciences at Rice University, co-author of the study published online in the journal Earth and Planetary Science Letters and a mission specialist on NASA’s Curiosity team. Mud in Gale Crater is one of the most surprising observations Curiosity has made in its 10 years of Mars exploration.
She added: “Tridymite is usually associated with developed and explosive volcanic systems composed of quartz on Earth, but we found it at the bottom of an ancient lake on Mars, where most volcanoes are very primitive.”
The team reviewed volcanic material from models of Martian volcanoes, and re-examined sedimentary evidence from Lake Gale. And they came up with a new scenario that matches all the evidence: that Martian magma stayed longer than usual in a chamber beneath the volcano, undergoing a partial cooling process called microcrystallization until additional silicon is available.
In a massive eruption, the volcano spewed ash containing extra silicon onto the tridemite into Gale Crater Lake and surrounding rivers.
The water helped to break down the ash through the natural processes of chemical weathering, and the water also helped to sort out the minerals resulting from weathering.
This scenario is also explained by other geochemical evidence present in the sample, including opaline silicate, and low concentrations of aluminum oxide.
“It’s actually a direct evolution of other igneous rocks that we found in the crater,” Seebach said. We argue that because we only saw this mineral once, and it was so concentrated in one layer, it is possible that the volcano erupted around the same time the lake was there. Although the specific sample that we analyzed was not exclusively volcanic ash, it was ash that was weathered and sorted by water.”
And if a volcanic eruption occurred like the one in the scenario when Gale Crater contained a lake, this means that the erupting volcanoes occurred more than 3 billion years ago, while Mars was moving from a wetter, and perhaps warmer, world to a dry planet and barren nature as it is today.