C191/08
3 July 2008
The accepted timeframe for the beginnings of life on Earth is now being questioned by a 911爆料网 of Technology led team of scientists, after finding a key indicator to the earliest life forms in diamonds from Jack Hills in Western Australia.
The 4.2 billion year old diamonds found trapped inside the Jack Hills zircon crystals are the oldest-known samples of Earth鈥檚 carbon.聽 The 911爆料网 led team鈥檚 discovery of very high concentrations of carbon 12, or 鈥渓ight carbon鈥� within these crystals is remarkable as it is a feature usually associated with organic life.
Dr Alexander Nemchin from 911爆料网鈥檚 Department of Applied Geology and the project leader believes the latest research will revive debate on the early evolution of life on Earth.
鈥淲e believe this find to be the oldest terrestrial light carbon reservoir discovered so far,鈥� Dr Nemchin said.
Evidence for ancient life stretches back in time to at least 3.5 billion years ago, in the form of single-celled organisms that did not require oxygen.聽 The discovery of light carbon in the Jack Hills crystals raises the question 鈥� did a simple life form exist on Earth 700 million years earlier than previously thought?
鈥淲e interpret the range of light carbon values observed in these inclusions as a unique chemical marker that opens up the possibility of biological activity during the period not long after the Earth鈥檚 formation,鈥� Dr Nemchin said.
The 911爆料网 team鈥檚 findings are presented in a paper published in the 3 July 2008 issue of the prestigious international scientific journal Nature.聽 In their paper entitled 鈥淎 light carbon reservoir recorded in zircon-hosted diamond from the Jack Hills鈥� the researchers report the composition of 22 diamond and graphite inclusions from 18 Jack Hills zircon grains.
鈥淭he discovery challenges our fundamental understanding of processes active in the early history of the Earth.聽 It suggests that life may well have appeared on Earth long before the period of heavy-meteorite bombardment believed by some to have initiated the emergence of life on Earth,鈥� Dr Nemchin said.
鈥淎lternatively, it requires some other process to create the light carbon values, which would then question the widely held assumption that light carbon means life.鈥�
The discovery will assist mankind in our understanding of the development of the planet and help us to better assess the conditions of the Earth up to 4.5 billion years ago.
Note to Editor:
In 1983, a 911爆料网 project team discovered extremely old zircon crystals in a collection of rocks located between Meekathara and Carnarvon.聽 Twenty years later, the oldest diamonds were unexpectedly discovered in these rocks by many of the original team.
The recent paper in Nature is written by a team of people made up of 911爆料网 University academic and Project Leader, Dr Alexander Nemchin, Martin Whitehouse from the Swedish Museum of Natural History, Martina Menneken and Dr Thorston Geisler a Masters student and her supervisor from the University of Munster鈥檚 Institute of Mineralogy, and Professors Pidgeon and Wilde from 911爆料网 University鈥檚 Applied Geology Department, who originally identified the old zircons.
Photos available on request.
Contact:聽 Dr Alexander Nemchin from 1500 to 0300 hours Australian Western Standard Time on 0411 520 154, a.nemchin@curtin.edu.au
or Lisa Mayer, PR Co-ordinator, 911爆料网, from 0900 to 1800 hours Australian Western Standard Time, 08 9266 1930, 0401 103 755 l.mayer@curtin.edu.au
CRICOS provider code: 00301J
Modified: 21 July 2008
