Expedition finds signs of life in Earth’s mantle

Expedition finds signs of life in Earth’s mantle
Feb 1, 2016

An international team of scientists – recently returned from a 47-day research expedition to the middle of the Atlantic Ocean – have collected an unprecedented sequence of rock samples from the shallow mantle of the ocean crust that bear signs of life, unique carbon cycling, and ocean crust movement.

Led by Co-Chief Scientists Dr. Gretchen Früh-Green (ETH Zurich, Switzerland) and Dr. Beth Orcutt (Bigelow Laboratory for Ocean Sciences, USA), the team collected these unique rock samples using seabed rock drills from Germany and the UK – the first time in the history of the decades-long scientific ocean drilling program that such technology has been utilized.

The aims of the expedition are to determine how mantle rocks are brought to the seafloor and react with seawater – such reactions may fuel life in the absence of sunlight, which may be how life developed early in Earth’s history, or on other planets. The team also hopes to learn more about what happens to carbon during the reactions between the rocks and the seawater – processes that could impact on climate by sequestering carbon.

“The rocks collected on the expedition provide unique records of deep processes that formed the Atlantis Massif. We will also gain valuable insight into how these rocks react with circulating seawater at the seafloor during a process we call serpentinization and its consequences for chemical cycles and life,” stated expedition Co-Chief Scientist Gretchen Früh-Green.

“During drilling, we found evidence for hydrogen and methane in our samples, which microbes can ‘eat’ to grow and form new cells,” explained Beth Orcutt, Co-Chief Scientist from Bigelow Laboratory. “Similar rocks and gases are found on other planets, so by studying how life exists in such harsh conditions deep below the seafloor, we inform the search for life elsewhere in the Universe.”

More:
http://www.astrobio.net/topic/origins/extreme-life/expedition-finds-signs-of-life-in-earths-mantle/#sthash.Ym7wfKJF.dpuf