(*) Recent publications indicate that the Earth has entered the sixth of these events, often referred to as the Holocene one.
A theory explaining one of these events proposes that widespread Archaeopteris forests may have contributed to accelerated pedogenesis leading to eutrophication. Positive HICE values support the continental glaciation theory for another of these events. Black shale often acts as the marker for these events. (*) Recent publications indicate that the Earth has entered the sixth of these events, often referred to as the Holocene one. For 10 points, name this type of event, the fifth of which occurred 65 million years ago because of an asteroid impact.
A theory explaining one of these events proposes that widespread Archaeopteris forests may have contributed to accelerated pedogenesis leading to eutrophication.
mass extinction [accept “extinction event” or “biotic crisis”]