Doesn't iridium most often come from meteors? That's why they trace the KT boundary to this big meteor they claim hit the Earth in that supposed time period. I figure what happened is that the meteor hit during the Flood and the timing was such that the iridium was carried on that particular layer which was dispersed throughout the world as all the sedimentary layers were being laid down during that event. Same basic idea, totally different timing and transport system.
Technically, the object that hit the Earth at the end of the Cretaceous period was an asteroid (about 10 km in diameter), not a meteor. A meteoroid is an interplanetary body, smaller than an asteroid, in orbit around the Sun. A meteor or fireball is the luminous phenomenon that we see when a meteoroid enters the Earth's atmosphere and burns up. A meteorite is a mass of stone or iron (derived from a meteoroid) that falls to Earth after the appearance of a fireball.