On California’s Channel Islands, some researchers believe that they have found strong evidence that a comet exploding over North America during the Pleistocene Era may have caused widespread extinctions.  With the discovery of tiny hexagonal diamonds, scientists believe that they are proof of a massive impact that could have wiped out the Clovis people, mastodons, and other early inhabitants of the continent. 

Researchers from another group issued a report recently on shock-synthesized hexagonal diamonds found in a soot layer from Arlington Canyon on Santa Rosa Island in California.  Their findings, published in “Proceedings of the National Academy of Sciences”, noted that Arlington Canyon is known as the location of the earliest human remains in North America, dating back 13,000 years.  This same soot layer was created at the same time as the disappearance of the pygmy mammoth. 

In 2007, these scientists theorized that a comet created the continental fires that led to the extinction of the Clovis people and 35 mammal types, including mastodons, mammoths, camels, and ground sloths.  They carefully logged a “black mat” of charcoal containing high levels of iridium, magnetic spheres, and nano-diamonds, and which exists all over North America.  This theory is very similar to the theory that it was some kind of extra-terrestrial impact that caused the extinction of the dinosaurs 65 million years ago.

There are, of course, alternate theories.  Geochemist Christian Koeberl of the University of Vienna in Austria has stated that “Diamonds of this sort are not uniquely characteristic of impact events.”  He cites, among other things, the absence of an impact crater as a significant problem with the comet theory.  Briggs Buchanan, and archaeologist from Simon Fraser University in Burnaby, British Columbia adds that other researchers looking at the same information have found that the “black mat” varies in age across North America, and that it appears to have a variety of origins.

These tiny hexagonal diamonds may be a tremendous breakthrough for paleontologists and archaeologists, answering some of the biggest questions facing them.  On the other hand, there are many ways that the earth creates these gems.  While this is not a definitive answer for most scientists, it is a step forward.