Volcanic activity on Mars peaked during the Noah’s and Hesperian periods, between 3 and 4 billion years ago, with minor eruptions in isolated locations that continued perhaps 3 million years ago. But so far there has been no evidence of recent geological explosive volcanism on the planet.
A team of planetary researchers from the University of Arizona, the Institute of Planetary Sciences and the Smithsonian Institution’s Center for Planetary and Planetary Studies have discovered a 53,000-year-old volcanic deposit in Elisium Planitia, a flat smooth plain near the Mars equator that also hosts numerous young flood lava fed by age cracks. from 500 million to 2.5 million years.
“This is perhaps the youngest volcanic deposit ever recorded on Mars,” said Dr. David Horvath, a scientist at the Institute of Planetary Science.
“If we were to compress the geological history of Mars in one day, it would happen at the last second.”
The deposit is about 13 km wide (8 miles), smooth and dark, and is symmetrically distributed around a segment of the Cerberus Fossae fissure system.
The properties, composition, and distribution of the volcanic material coincide with what might be expected from a pyroclastic eruption, an explosive magma eruption triggered by the spread of gases.
“When we first noticed this deposit, we knew it was something special,” said Dr. Jeff Andrews-Hanna, a researcher in the lunar and planetary lab at the University of Arizona.
“The deposit was unlike anything else found in the region, or in fact on the whole of Mars, and was more reminiscent of the characteristics created by older volcanic eruptions on the Moon and Mercury.”
“This feature covers the surrounding lava flows and appears to be a relatively fresh and thin layer of ash and rock, representing a different style of eruption than the previously identified pyroclastic characteristics,” said Dr. Horvath.
“This eruption could have released ash up to 10 km (6 miles) into the atmosphere of Mars. It is possible that such deposits were more frequent, but that they were eroded or buried. “
The site of the eruption is about 1,600 km (1,000 miles) from NASA’s InSight landing site, which has been studying seismic activity on Mars since 2018.
“The young age of this site absolutely opens the possibility that there could still be volcanic activity on Mars, and it is intriguing that the recent marches discovered by the InSight mission originate from Cerberus Fossae,” said Dr. Horvath.
“A volcanic deposit like this also creates the possibility of habitable conditions beneath the surface of Mars in recent history,” he added.
“The interaction of rising magma and the ice substrate of this region could have brought favorable conditions for microbial life quite recently and increased the possibility of existing life in this region.”
“It is exceptional that one region hosts the epicenters of today’s marches, the latest floods, the latest lava flows and now even more recent explosive volcanic eruptions,” said Dr. Andrews-Hanna.
“This may be the latest volcanic eruption on Mars, but I think we can be sure it won’t be the last.”
“The volcanic deposit described in this study, along with the continuous seismic rumble in the interior of the planet discovered by InSight and possible evidence for the release of methane plumes into the atmosphere discovered by NASA’s MAVEN orbiter, suggest that Mars is far from a cold, inactive world. ”
The paper on the findings was published in April 2021 in the journal Icarus.
David G. Horvath et al. 2021. Evidence for geological recent explosive volcanism in Elisium Planitia, Mars. Icarus 365: 114499; doi: 10.1016 / j.icarus.2021.114499