Mars had its own version of plate tectonics

Plate tectonics is not something most people associate with Mars. In fact, the planet's dead core is one of the primary reasons for its famous lack of magnetic field. And since active planets are one of the primary driving factors of plate tectonics, it's clear why that general concept exists.

However, there are some features on Mars that we think are related to plate tectonics—volcanics. A new paper by researchers at the University of Hong Kong (HKU) looks at how different types of plate tectonics could have created different types of volcanoes on the Martian surface.

Usually, when you think of volcanoes on Mars, you think of the massive shield volcanoes like Olympus Mons found in places on Earth like Hawaii. These are formed when layers of lava erupt repeatedly over millions of years. Those eruptions are not affected by how any underlying plates move beneath them. But they form a fundamentally different landscape than anywhere else on the planet.

One of the main differences is that volcanoes have a higher concentration of silica. Most of the Red Planet has a relatively low silica concentration and consists primarily of basalt. However, they clearly have elevated silica levels, and Dr. Joseph Michalski and his colleagues at HKU think they know why.

During the Archean Age, 3 billion years ago, on Earth, geologists believe that a type of plate tectonics called „vertical tectonics” forced the planet's crust to slide into the planet's crust. There, it was reformed, injected with high concentrations of silica, and then re-emitted to the surface by erupting volcanoes.

This conveniently explains why volcanic silica levels on Mars are higher than in other parts of the planet. To back up their findings, the paper describes signs of several volcanic types, such as stratovolcanoes and lava domes, that contain high silica concentrations and may be due to this type of theoretical tectonics.

On Earth, other active geological processes have destroyed rocks that could have been formed by these processes billions of years ago. But Mars has almost no geological activity, so it provides a clear picture of the geology resulting from these processes.

This body of work contributes to our overall understanding of the geology of Mars, and the discovery of many additional volcanoes will be of interest to enthusiasts for years to come. But for now, this new theory of Mars' geological history is another step forward in our understanding of the Red Planet.