tectonic plate separations mass species extinctions orbital path changes magnetic pole reversals
Some localized layers of rock contain the element iridium. Iridium is most often found in space objects such as meteoroids and asteroids. The discovery of these iridium-containing layers has been matched to which phenomena in Earth's history?

Options:
- tectonic plate separations
- mass species extinctions
- orbital path changes
- magnetic pole reversals

mass species extinctions