> it may have triggered what’s called the Hirnantian glaciation stage Maybe. but per the Brittanica article cited: > No concentration of iridium has been ide

> it may have triggered what’s called the Hirnantian glaciation stage Maybe. but per the Brittanica article cited: > No concentration of iridium has been identified near the extinction that would suggest a bolide (meteorite or comet) impact like the one identified at the end of the Cretaceous Period.