This image shows a semi-circular crater more than 180 km across. The site of the Chicxulub meteorite impact. A meteorite fragment from Tenham in Queensland is of a similar type to the one that may have caused the mass extinction event 65 million years ago. Flecks of iron-nickel sparkle in this photograph of the cut surface of a meteorite. Meteorites contain some minerals that are not found in rocks on Earth.
Iridium is a chemical element that is very rare on Earth but commonly found in meteorites.
A thin band of clay, rich in iridium, has been found at more than 100 sites worldwide the fall-out from the dust cloud that circled the Earth after the meterorite impact. Shocked' quartz has lines running in many directions, as if it has been fractured for example, by the massive pressure of a meteorite impact. Massive fires produced by hot projectiles may well have burnt regional forests into a mix of charcoal and dust in which only ferns could survive.