The last volcanic activity on Mars ceased about 50 million years ago, around the time when large number of Earth's plant and animal species, including dinosaurs, went extinct, according to a new NASA study. The research reveals that the giant Martian volcano Arsia Mons produced one new lava flow at its summit every one to three million years during the final peak of activity. The last volcanic activity there ceased about 50 million years ago - around the time of Earth's Cretaceous-Paleogene extinction event. "We estimate that the peak activity for the volcanic field at the summit of Arsia Mons probably occurred approximately 150 million years ago - the late Jurassic period on Earth and then died out around the same time as Earth's dinosaurs," said Jacob Richardson of NASA's Goddard Space Flight Centre in Greenbelt in the US. "It's possible, though, that the last volcanic vent or two might have been active in the past 50 million years, which is very recent in geological terms," he added. Researchers mapped the boundaries of the lava flows from each of the 29 volcanic vents and determined the stratigraphy, or layering, of the flows. They also performed a technique called crater counting - tallying up the number of craters at least 100 meters in diameter - to estimate the ages of the flows. Researchers, including those from University of South Florida in the US, combined the two types of information to determine the volcanic equivalent of a batting order for Arsia Mons' 29 vents. The oldest flows date back about 200 million years.
The youngest flows probably occurred 10 to 90 million years ago. The study was published in the journal Earth and Planetary Science Letters.