{"id":805,"date":"2017-05-18T10:15:42","date_gmt":"2017-05-18T09:15:42","guid":{"rendered":"http:\/\/www.mub.eps.manchester.ac.uk\/in-abstract\/?p=805"},"modified":"2017-12-04T11:01:23","modified_gmt":"2017-12-04T11:01:23","slug":"origin-and-degassing-history-of-earths-atmosphere","status":"publish","type":"post","link":"https:\/\/www.mub.eps.manchester.ac.uk\/in-abstract\/origin-and-degassing-history-of-earths-atmosphere\/","title":{"rendered":"The origin and degassing history of the Earth’s atmosphere revealed by Archean xenon"},"content":{"rendered":"

The contribution of comets explains the xenon mystery of the Earth’s atmosphere<\/strong><\/p>\n

Noble gases are chemically inert elements that act as powerful tracers for investigating the origin and evolution of the Earth\u2019s atmosphere. Xenon (Xe) is the heaviest stable noble gases and has nine isotopes. The Xe isotope composition of the modern atmosphere is characterised by being elementally depleted relative to other noble gases and isotopically fractionated, features that are not represented in any other solar system body (meteorites or the Sun) and are difficult to explain. Researchers from the University of Manchester with collaborators in France, have obtained high precision Xe isotope analyses of ancient air trapped in fluid inclusions in rocks from the Barberton area, South Africa. The researchers showed that the fluid inclusions have been preserved intact for 3.3 billion years and have a Xe isotope “fingerprint” indicative of a hitherto theoretical component known as U-Xe. U-Xe is quite different from Xe found in the Earth\u2019s mantle, meteorites or the solar wind, and must have been added to the Earth\u2019s atmosphere during the final stages of terrestrial accretion. As primitive volatile-rich objects in the solar system, comets may potentially may carry such an exotic primordial component, possibly inherited from other planetary systems formed in the vicinity of our Sun. The work therefore suggests that some of the Earth\u2019s atmosphere may have been brought to the planet by comets billions of years ago.<\/p>\n

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