Ancient Scottish meteorite strike rewrites timeline of life on land

The impact, responsible for creating the Stac Fada Member rock formation, was long believed to have occurred 1.2 billion years ago. Using zircon crystals as geological timekeepers, Curtin scientists pinpointed the event's actual age with greater precision.

"These microscopic crystals recorded the exact moment of impact, with some even transforming into an incredibly rare mineral called reidite, which only forms under extreme pressures," said Professor Chris Kirkland from Curtin's Frontier Institute for Geoscience Solutions.

The presence of reidite provided clear confirmation that a meteorite impact had formed the Stac Fada deposit. The team developed a model to interpret how the impact disrupted zircon crystal structures, determining that the collision occurred 990 million years ago.

Kirkland noted the event aligns chronologically with the emergence of early freshwater eukaryotes-organisms considered precursors to plants, animals, and fungi. "The revised dating suggests these life forms in Scotland appeared at a similar time to a meteorite impact," he said.

This synchronicity raises compelling questions about the potential environmental effects of large meteorite strikes on early life. "Understanding when meteorite impacts occurred helps us explore their potential influence on Earth's environment and the expansion of life beyond the oceans," Kirkland added.

Although the impact crater has yet to be located, researchers believe the new evidence will aid in identifying its position.

Research Report:A one-billion-year-old Scottish meteorite impact