Thursday, March 09, 2006

Siberian Trap=Mass Dino Extinction?

University of Leicester geologists, Professor Andy Saunders and Dr Marc Reichow, are taking a fresh look at what may actually have wiped out the dinosaurs 65 million years ago and caused other similarly cataclysmic events.
The idea that meteorite impacts caused mass extinctions has been in vogue over the last 25 years, since Louis Alverez’s research team in Berkeley, California published their work about an extraterrestrial iridium anomaly found in 65-million-year-old layers at the Cretaceous-Tertiary boundary. This anomaly only could be explained by an extraterrestrial source, a large meteorite, hitting the Earth and ultimately wiping the dinosaurs – and many other organisms - off the Earth’s surface.

Current research suggests that the causes of the extinctions may come from within our own planetthe eruption of vast amounts of lava that brings a cocktail of gases from deep inside the Earth and vents them into the atmosphere.

Flood basalt eruptions are an alternative kill mechanism. These do correspond with all main mass extinctions, within error of the techniques used to determine the age of the volcanism. Furthermore, they may have released enough greenhouse gases (SO2 and CO2) to dramatically change the climate. The largest flood basalts on Earth (Siberian Traps and Deccan Traps)coincide with the largest extinctions (end-Permian, and end-Cretaceous). The gases released by volcanic activity lead to a prolonged volcanic winter induced by sulphur-rich aerosols, followed by a period of CO2-induced warming.

The 250 million year old Siberian Traps are the largest known continental flood basalt province. Using radiometric dating techniques, they hope to constrain the age and, combined with geochemical analysis, the extent, of the Siberian Traps. Using these data they hope to be able to assess the amount of SO2 and CO2 released into the atmosphere 250 million years ago, and whether or not this caused climatic havoc, wiping out nearly all life on earth.

More information is available HERE.

Volcano from HERE.

NB: This is an interesting example of a press release for work that has not yet been done – it’s an announcement for a grant that has been received to start the research. The suggestion that the Siberian and/or Deccan Traps are the real cause of Earth’s major extinction events has been around for some time now. We’ll see what they come with in a year or two.