Found: Surviving evidence of Earth's formative years

Discussion in 'Earth Science' started by paddoboy, May 12, 2016.

  1. paddoboy Valued Senior Member

    Messages:
    21,647
    Found: Surviving evidence of Earth's formative years
    May 12, 2016

    Please Register or Log in to view the hidden image!


    Photograph of Baffin Island, where a research team was able find a geochemical signature of material left over from the early melting events that accompanied Earth's formation. Credit: Courtesy of Don Francis of McGill University
    New work from a team including Carnegie's Hanika Rizo and Richard Carlson, as well as Richard Walker from the University of Maryland, has found material in rock formations that dates back to shortly after Earth formed. The discovery will help scientists understand the processes that shaped our planet's formative period and its internal dynamics over the last 4.5 billion years. It is published by Science.



    Read more at: http://phys.org/news/2016-05-surviving-evidence-earth-years.html#jCp
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. paddoboy Valued Senior Member

    Messages:
    21,647
    http://science.sciencemag.org/content/352/6287/809

    Preservation of Earth-forming events in the tungsten isotopic composition of modern flood basalts

    Abstract
    How much of Earth's compositional variation dates to processes that occurred during planet formation remains an unanswered question. High-precision tungsten isotopic data from rocks from two large igneous provinces, the North Atlantic Igneous Province and the Ontong Java Plateau, reveal preservation to the Phanerozoic of tungsten isotopic heterogeneities in the mantle. These heterogeneities, caused by the decay of hafnium-182 in mantle domains with high hafnium/tungsten ratios, were created during the first ~50 million years of solar system history, indicating that portions of the mantle that formed during Earth’s primary accretionary period have survived to the present.

    Isotopes isolated after impact
    Details about how Earth formed are gleaned from the daughter products of certain short-lived radioactive isotopes found in rocks. Rizo et al. describe subtle tungsten isotope variations in rocks from the very deep mantle in Baffin Island and the Ontong Java Plateau (see the Perspective by Dahl). The results suggest that portions of Earth have remained unmixed since it formed. The unmixed deep mantle rocks also imply that Earth's core formed from several large impact events.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.

Share This Page