Volcanoes on Mars grew much slower than those on Earth, according to a study published in Nature Communications this week. These finding are made from the first reconstruction of the evolution of a single volcano on Mars using meteorites.
The volcanoes on Mars are the largest in the solar system and are usually formed by mantle plumes similar to those found on Earth, for example on Hawai'i. Unlike on Earth, the crust on Mars does not move over mantle plumes, allowing the volcanoes to erupt in the same place for extraordinary lengths of time, and thereby creating supersized volcanoes. However, constraining the evolution of volcanoes on Mars had proved challenging due to the difficulty of direct sampling on Mars.
Benjamin Cohen and colleagues discovered that nakhilite meteorites were sourced from an individual volcano on Mars, created after a single impact event around 10.7 million years ago. By determining the age of these meteorites, the team reconstructed the growth of the Martian volcano at a rate of 0.4-0.7 metres per million years, with four discrete eruptive events over a period of approximately 93 million years. The finding shows that the Martian volcano grew 1,000 times slower than similar volcanoes on Earth (such as Mauna Kea, Hawai'i) and therefore redefines our understanding of volcanism on Mars, suggesting that Mars was far more volcanically active earlier in its history than previously thought.