ASU Biogeochemist Ariel Anbar (IMAGE) Arizona State University Caption ASU biogeochemist Ariel Anbar and an international team of scientists who analyzed layers of sedimentary rock in a kilometer-long core sample from the Hamersley Basin in Western Australia report finding evidence of a hint of oxygen in Earth's atmosphere 50 to 100 years earlier than previously known. Sliced longitudinally, half of the core is housed in laboratories at Arizona State University and the other half is archived at the Geological Survey of Western Australia. Credit Arizona State University photo by Tim Trumble Usage Restrictions Photo credit to photographer and Arizona State University. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.