Scientists from the University of Houston have discovered that volcanism on Mars occurred over a period of at least two billion years, much longer than previously thought. Their findings are based on geochemical analyses of a Martian meteorite found in northwest Africa and have been published in Science Advances. The meteorite, a type of igneous rock known as shergottite, was found to have an age of approximately 2.4 billion years and is similar in composition and origin to a group of ten other Martian meteorites with ages of 327 to 574 million years. These rocks were likely ejected into space towards the Earth during a single impact 1.1 million years ago, which further suggests that they were all derived from the same volcanic source. Therefore, the spatial and temporal relationships of these meteorites indicate that volcanism must have occurred for over two billion years at the same location. This amazing discovery sheds new light on the formation of the planet and suggests that Mars was to some of the longest-lived volcanoes in the Solar System.
Journal reference: Lapen, T. J., Righter, M., Andreasen, R., Irving, A. J., Satkoski, A. M., Beard, B. L., Nishiizumi, K., Jull, A. J. T. & Caffee, M. W. (2017). Two billion years of magmatism recorded from a single Mars meteorite ejection site. Science Advances, 3(2).
Image: Olympus Mons, the largest volcano on Mars, as seen from the Viking 1 Orbiter. Credit: NASA.
Dallol is a volcanic explosion crater, or maar, in the Danakil Depression in northeast Ethiopia. It is located approximately 50 meters below sea level and has been formed by the intrusion of magma underneath Miocene evaporite deposits in the Afar Triangle of the East African Rift system, followed by several eruptions. Subsequent hydrothermal activity has led to the formation of hot springs and brines in a landscape with striking red, yellow and green colors related to the presence of iron oxide, sulfur and microbes. Dallol is known as one of the hottest places on Earth, with average temperatures of 35 degrees Celsius throughout the year.
Information source: Smithsonian Institution National Museum of National History Global Volcanism Program
Image: Salt and sulfur deposits near the hot springs of Dallol in the Danakil Depression, Ethiopia. Credit: Ji-Elle, Wikimedia Commons.
Mount Erebus is the southernmost active volcano on Earth and is located on Ross Island in Antarctica. It has an elevation of 3794 meters and is surrounded by three inactive volcanoes, Mount Terror, Mount Bird and Mount Terra Nova. Volcanism on Ross Island is related to the presence of the Erebus hotspot in the deep subsurface and as a result, continuous eruptions occur from the persistent lava lake in the inner crater of Mount Erebus. The volcano is also known for its ice fumaroles, towers of ice that form around gases escaping from vents in its surface.
Information source: Mount Erebus Volcano Observatory
Image: Mount Erebus and the surrounding landscape on Ross Island, Antarctica. Credit: Hannes Grobe, Wikimedia Commons.
Mount Nyiragongo is an active stratovolcano in the Virunga Mountains in the Democratic Republic of the Congo. The volcano has an elevation of 3470 meters and its main crater usually contains a large lava lake. Volcanism at Mount Nyiragongo is related to the presence of the Albertine Rift, the western branch of the East African Rift system, where the African tectonic plate is splitting into two.
Information source: Virunga National Park Service
Image: Lava lake in the crater of Mount Nyiragongo in the Virunga Mountains, Democratic Republic of the Congo. Credit: Caj Tjeenk Willink, Wikimedia Commons.