What does the iridium rich layer tell us?

The iridium-rich layer, often associated with the Cretaceous-Paleogene (K-Pg) boundary, provides evidence for a significant extraterrestrial impact event, likely the asteroid that contributed to the mass extinction of the dinosaurs around 66 million years ago. This layer, found in various geological sites worldwide, contains higher concentrations of iridium than typically found on Earth, suggesting that it originated from an asteroid or comet. Its presence helps scientists understand the catastrophic environmental changes that occurred during this period, including climate shifts and ecological disruptions. This discovery has been pivotal in studying the links between impact events and mass extinctions.