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Volcanoes are a common feature on the surfaces of solid planets within the solar system, as a result of magmatic activity occurring within the planetary crust. On Earth, volcanism is driven primarily by heat and crustal recycling associated with plate tectonics, but Mars lacks plate tectonics and the driver of volcanism is not well understood.
Recent research by Professor Joseph MICHALSKI, a geologist at the Department of Earth Sciences at the University of Hong Kong (HKU), has revealed intriguing insights into volcanic activity on Mars. He proposes that Mars has significantly more diverse volcanism than previously thought, driven by an early form of crustal recycling called vertical tectonics. The findings, recently published in Nature Astronomy, shed light on the ancient crust of Mars and their potential implications for understanding early crustal recycling on both Mars and Earth.
Traditionally, Mars is known to have large shield volcanoes similar to those on Hawaii. However, it was not known that Mars also possessed the various explosive volcanoes that form on Earth due to the recycling of the Earth’s crust.
Recent research by Professor Michalski and his international team uncovers a large number of diverse volcanoes in the ancient crust of Mars. “We have known for decades that Mars has volcanoes, but most of the recognized volcanoes correspond to large basaltic shield volcanoes similar to those that form Hawaii,” he explains. «In this work we show that the ancient crust has many other types of volcanoes, such as lava domes, stratovolcanoes, calderas and large shields of ash, not lava. Additionally, most scientists view Mars as a planet composed of basalt, which is low in silica and represents little evolution of the Earth’s crust, but these volcanoes are high in silica, meaning they formed at from a complex process of magma evolution unknown until now.’
The paper suggests that intense volcanism occurred on ancient Mars, causing the crust to collapse into the mantle, where rocks were remelted, resulting in magmas with high silica content. This tectonic process, called vertical tectonics, is supposed to have occurred on the ancient Earth, but Earth’s rocks from that period (the Archean, more than 3 billion years ago) are greatly modified by later geological activity, so that we cannot see evidence of this process clearly on this planet. Therefore, exploring other planets like Mars, which has volcanism but not plate tectonics, may help reveal the mysteries of early crustal recycling both on the Red Planet and, by analogy, on the early Earth.
Professor Michalski concluded: ‘Mars contains critical geological pieces that help us understand not only that planet, but also the Earth. Martian volcanism is much more complex and diverse than previously thought.’
‘This is an important discovery because it has revealed that recycling of the Earth’s crust can occur not only in plate tectonic regimes dominated by horizontal movements, but can also occur in pre-plate tectonic regimes dominated by vertical movements. “This finding may help Earth scientists address long-term controversial questions about how and when felsic continents formed on our planet (Earth),” said Professor Guochun ZHAO, Professor of Earth Sciences at HKU. .
You can access the magazine article here: https://www.nature.com/articles/s41550-023-02191-7
About Professor Joseph Michalski
Professor in the Department of Earth Sciences and deputy director of the HKU Space Research Laboratory, he collaborated with colleagues from mainland China and the US on this research project. He is a researcher at the Hong Kong Research Grants Council and winner of the Tencent Xplorer Prize in 2023. Funding for this work was provided by the RGC Collaborative Research Fund.