Scientists in Australia have uncovered what they say is the biggest asteroid impact area ever discovered. The 400 kilometer (250 mile) wide region is buried deep in the Earth’s crust and consists of two different impact scars.
It would have been ‘curtains’ for many species in the world at the time,” said Dr. Glikson.
However, the team, which released its findings in the geology journal ‘Tectonophysics,’ hasn’t been able to link the event to any known annihilation.
It is a puzzle – we cannot find an extinction event that fits this crash. I’ve a feeling the impact may be older than 300 million years,” said Dr. Glikson.
The stones around the impact zone are about 300 to 600 million years old, however a layer of ashes that would have been thrown up by the impact hasn’t yet been found, as sediment in the stone layers form an identical interval.
Substantial impacts such as these may have had a lot more important part in the Earth’s development than previously believed,” Dr. Glikson said.
The excavation returned bits of stone that were turned into glass by excessive temperature and pressure, consistent with a substantial impact. The rocks around the impact zone are roughly 300 to 600 million years old, but a layer of ash that would have been thrown up by the impact has not been detected as sediment in rock layers from the same period.
The large meteorite believed to have killed the dinosaurs 66 million years ago corresponds to a layer of sediment in rocks around the world. The apparent impact zone in the Warburton Basin was discovered by accident while scientists were drilling 2km under the Earth’s surface for a geothermal research project.
The discovery of the Warburton twin impacts constitutes a milestone in the study of the impact history of Earth, including research of impact events associated with 2.5 billion to 3.5 billion years old formations in the Pilba Craton in Western Australia. The more we know about these impacts, the better we can understand other phenomena, such as mass extinctions, the formation of certain geological structures over time and related magmatic events.
As an after thought, it also paints a vivid picture of what might have happened on that fateful day a few hundred million years ago, and the catastrophe it must have brought. Such collisions played a vital role in the turnover of life on Earth:
If there were no such impacts, humans would not be here.