The purpose of Appendix V is to summarize the most significant impacts and extinctions of the past 250 million years. Not all really big impacts have led to major extinctions.

Not all really big impacts have led to major extinctions. However, all major extinctions were caused by the initial effects of a really big impact and its antipodal effects

In one way or another, really big impacts did cause all of the major extinctions of the past 250 million years. The major extinctions prior to the Permian are too obscure to figure out.


When we look at big and really big impact and their results, there are two exceptions to the usual rule.

The usual rule is that a big impact will create a hotspot at the antipode that will move in the direction of the directional force imparted by the impact. A really big impact will not only create a hotspot, but will also uplift a continent and cause a major extinction.

The first exception to the rule is the impact at Manicouagan 214 MYA. The impact was large enough (barely) to uplift the Western Antarctica continent. However, this event did not create a major extinction. It did create a minor extinction, but it did not cause enough damage to create a major extinction.

The second exception to the rule is the huge deep ocean impact 132 MYA that uplifted the South American continent. This impact and its huge lava outflow at Parana and Etendeka caused the Valanginian Weissert Ocean Anoxic Event, but not an official major extinction.

An analysis of these two exceptions shows that, even though they didn't follow the rule, they came very close to following the rule. The other big and really big impacts did follow the rule.

A summary of all of the big and really big impacts that are covered in this book is shown below.

250 Antarctic Crater Siberia Permian
214 Manicouagan Western Antarctica minor
202 Ocean Impact, probably now moved to South Sandwich Islands between South America and Antarctica Eastern North America Triassic Central Atlantic Magmatic Provinces (CAMP) - caused by leaky uplift of Eastern North America
132 Deep Ocean South America N/A The Valanginian Weissert Ocean Anoxic Event may or may not have been a major extinction
65 Chicxulub India End Cretaceous
35 Chesapeake Bay no no Hotspot causing basalt underlayment and eventual flood basalt around eastern Australia. Not big enough to cause a major extinction