CHAPTER 1.1
LOOKING AT THE MAJOR MASS EXTINCTION EVENTS

   
CHAPTER 1.1
LOOKING AT THE MAJOR MASS EXTINCTION EVENTS

There have been six major (and many minor) mass extinction events on earth during the past 510 million years. Scientists have put forth many explanations for these extinction events. At present, there is no conclusive agreement about the cause of any one of these events, much less all of the extinction events. Scientists can't even agree on the events, themselves (i.e. Was the Triassic extinction event really an extinction event?).

A summary of the major mass extinction events and the most accepted proposed causes is as follows:

1. Cambrian Extinction—510 MYA
a. Glacial Cooling
b. Oxygen Depletion

2. Ordovician Extinction—440 MYA (50% of all animal families go extinct)
a. Glaciation and Sea Level Lowering

3. Devonian Extinction—365 MYA (30% of all animal families go extinct)
a. Glaciation
b. Meteorite Impact

4. Permian Extinction—250 MYA (60% of all animal families go extinct)
a. The Formation of Pangaea
b. Glaciation
c. Volcanic Eruptions

5. Triassic Extinction—202 MYA (35% of all animal families go extinct)
a. Fluctuating Sea Levels
b. Bolide Impact
c. Volcanic Eruptions
d. Possibility there wasn't a mass extinction

6. End-Cretaceous Extinction—65 MYA (50% of all animal families go extinct)
a. Meteorite Impact
b. Volcanic Eruptions


ONE STOP SHOPPING


This book proposes the idea that all of these major mass extinction events (and many of the minor ones), stem from just one cause: The natural kinetic effects of a cosmic impact on the planet Earth.

Certainly, it is not new to propose that cosmic impacts have had a devastating effect on the planet earth.

In the 1980s, Louis and Walter Alvarez found large amounts of iridium (which is only present on earth in significant amounts via impacts from outer space) at the black ash layer which separates the Cretaceous period from the Tertiary, 65 MYA (the K-T boundary). This relatively large presence of iridium led them to propose that a large meteorite impact had caused the End-Cretaceous extinction.

A few years later, an analysis of oil exploration maps made by mapping magnetic anomalies showed an overgrown and eroded impact site at Chicxulub in the Yucatan peninsula of Mexico. The site dated to 65 MYA. Furthermore, in other excavated sites of 65 MYA, the concentrations of iridium at the at the K-T boundary and the amount of ash at that boundary generally increased as the explored site was located nearer to the Chicxulub impact location.

With this confirmation of the "smoking gun" (the Chicxulub crater), many scientists have accepted the idea that a meteorite impact was the cause of the End-Cretaceous extinction. Furthermore, many scientists have looked to cosmic impacts to explain other extinction events.

However, the great majority of these scientists have focused on the effects at the impact site, itself. While these impact site effects would have considerable, I do not believe that these effects would have been sufficient to cause the major extinction events. Neither do several other scientists, each with their own set of reasons.

I believe that it was the effects at the antipode (the exact opposite side of the earth), resulting in devastating and sustained volcanism, that were the primary cause of the major extinction events.

As David Charles Weber notes in a paper published on 3/28/10, writing about the effects of the devastation caused at the impact site of the Chicxulub crater:
"This would cool the earth to create continuous killing frosts in the upper latitudes for as long as 10 years and droughts in the tropics. But, this degree of sun blotting from a localized explosion from the meteor impact would not have killed all of the plants near the equator, even with the cooling and the drought. So, this doesn't explain the complete eradication of the dinosaurs, which would have survived near the equator and then repopulated the earth." 14

But, thousands of years of worldwide volcanic winter caused by massive, aggressive and persistent volcanic action at the antipode of the impact would explain the complete destruction of the dinosaurs ... especially if this large volcanic hotspot was located at the edge of the moving continent, so that water-laden crust could be subducted into the volcanic system, causing steam and explosive results.

Please note that all of the reasons given for extinction (glaciation, oxygen depletion, and sea level lowering), except for "the formation of Pangaea," would be the logical consequences of massive volcanism, which would block the sun with clouds of sulfur and ash , thereby lowering the temperature, which would initiate glaciation, which would lower the sea level. And, of course, the massive volcanism would be caused by a very large impact and this massive volcanism would be located at or near the antipode of the very large impact.