Monday, October 01, 2007

Listen, do you smell that?!

Late Archean Biospheric Oxygenation and Atmospheric Evolution. 2007. Alan J. Kaufman et al. Science 317: 1900-1903.

A Whiff of Oxygen Before the Great Oxidation Event?. 2007. Ariel D. Anbar et al. Science 317: 1903-1906.

From the press release:

Two teams of scientists report that traces of oxygen appeared in Earth’s atmosphere roughly 100 million years before the “Great Oxidation Event” 2.4 billion years ago. The Great Oxidation Event is when most geoscientists think atmospheric oxygen rose sharply from very low levels and set the stage for animal life that followed almost two billion years later.

graphs=real science
Analyzing layers of sedimentary rock in a kilometer-long core sample they retrieved in 2004 from the Hamersley Basin in Western Australia, the researchers found evidence for the presence of a small but significant amount of oxygen 2.5 billion years ago in the oceans and likely also in Earth’s atmosphere.

Because the core was recovered from deep underground, it contains materials untouched by the atmosphere for billions of years.

A cartoon by Tom Bagley, just beacuse I can.