May 3 (UPI) -- The impact of ancient meteorites sparked volcanic eruptions, a team led by Trinity College Dublin geochemists says in a report.
The team studied rocks in a massive crater in Sudbury, Ontario, where a deep basin was formed 1.85 billion years ago by a bolide, a meteor which exploded in the atmosphere.
Small volcanic fragments of the crash remain, each shaped like a crab claw. Their shape indicates they were formed when gas bubbles expanded in molten rock and then suddenly exploded.
The researchers findings indicate that the composition of the volcanic fragments changed over time. Immediately after the impact, volcanism, or the phenomenon of eruption of molten rock, is directly related to melting of the earth's crust. Over time, though, it was fed by magma, underground molten rock, coming from deeper levels within the earth.
"This is an important finding, because it means that the magma sourcing the volcanoes was changing with time," Balz Kamber, a professor of geology and mineralogy at Trinity, said in a press release. "The reason for the excitement is that the effect of large impacts on the early earth could be more serious than previously considered. The intense bombardment of the early earth had destructive effects on the planet's surface but it may also have brought up material from the planet's interior, which shaped the overall structure of the planet."
The findings, published in the Journal of Geophysical Research: Planets, suggest similar events may have occurred on the moon and other planets. The lack of plate tectonics or erosion there keeps the surface features intact, though.