Exploring the scale of meteorite impact from minerals

Laboratory-based shock experiments on minerals

Key Points
– Shock experiments were performed on baddeleyite (a zirconia mineral) in a laboratory, during which time its crystal structure dynamics were observed directly using a synchrotron X-ray.
– The crystal structure changed upon compression before returning to its original state when released.
– Geologists can use this information to estimate the scale of a past impact event using baddeleyite present in rocks.

Collisions of celestial bodies have formed and affected the evolution of planets. One well-known hypothesis is that an asteroid impact caused the mass extinction of dinosaurs on Earth ~65 million years ago. Understanding the scale of an impact event is essential to studying the evolution of a similar planet. Impact events cause shock metamorphism in rocks and minerals in the crust of a planet (see Fig. 1), and shock metamorphosed minerals can be used to identify and date impact events and as barometric indicators. Baddeleyite (ZrO2) is one mineral that can be used as a shock-pressure barometer. The mineral is widespread on Earth, the Moon, Mars, and meteorites; it is also known to show traits of shock

Read more on the KEK (Photon Factory) website

Image: Meteorite impact produces shock compressions in rocks. Source: KEK (Photon Factory)