The Elysium Planitia region on Mars shows a mantle more similar to the Earth’s one

A solidified lava flow over the side of a crater rim of Elysium (Photo NASA HiRISE image, David Susko, LSU)
A solidified lava flow over the side of a crater rim of Elysium (Photo NASA HiRISE image, David Susko, LSU)

An article published in the journal “Scientific Reports” describes a research on Elysium Planitia, a volcanic region near Mars’ equator. A team of researchers from Louisiana State University led by David Susko used data collected by the Mars Global Surveyor (MGS), Mars Odyssey Orbiter and the Mars Reconnaissance Orbiter space probes to study the Martian mantle finding some similarities with the Earth’s one and traces of recent volcanic activity.

Elysium Planitia is the second Martian volcanic complex for width behind Tharsis, where there is the giant Olympus Mons and reaches 16 kilometers (about 10 miles) of height. The lava surrounding its three large volcanoes, Hecates Tholus, Elysium Mons and Albor Tholus, contains traces of the most recent volcanic activity on Mars. Generally, volcanism on Mars dates back to a period between 3 and 4 billion years ago but in this region the lava flows date back to a period ranging from 3 to 4 million years ago.

Elysium Planitia’s characteristics suggest that the volcanoes might erupt again sooner or later, and that’s already a surprise on a planet now considered geologically very quiet but they’re interesting for other reasons as well. The Martian mantle underwent major changes during the first part of the planet’s history and today researchers are realizing that it’s more complex than expected, even showing some similarities to the Earth’s one.

Images and other data collected by NASA’s space probes over the years allowed the researchers to examine Elysium Planitia’s chemical and morphological characteristics finding indications of the complexity of the mantle that formed under Mars’ surface. Geochemical differences were found between the younger southeast regions and the northwest ones, which are 850 million years older, due to processes related to igneous rocks.

One of the questions concerned the levels of thorium and potassium lower than expected because those are radioactive elements that are abundant in the other volcanic regions of Mars. A possibility is that the levels of those two elements exhausted due to volcanic eruptions over billions of years. The chemical changes that occurred in the mantle over time are a common feature on Earth so it might be possible to apply the same geochemical models to better understand that part of Mars’ history.

Such a varied stratification of the mantle at the volcano Elysium Mons could have been caused by the weight of its lava flows that melted the mantle at different temperatures. Another hypothesis is that in certain areas of Elysium Planitia the lava flowed from different parts of the mantle. In any case, that’s evidence of Mars’ complex geological history in which the weight of the volcanoes on the mantle was probably crucial.

These Martian geological studies are interesting from the scientific point of view but might also have practical consequences. The greater similarities with Earth that were detected also mean more resources, starting with the minerals that could be exploited, for a possible future human colony.

Elysium Mons (Photo NASA/JPL)
Elysium Mons (Photo NASA/JPL)

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