The Lesser Known Melting Mechanisms

Discussion in 'Earth Science' started by WhiteStar33, Nov 23, 2009.

  1. WhiteStar33 Registered Member

    Messages:
    2
    Hello,

    I am currently researching mantle melting mechanisms that are NOT decompression, heating or fluid inclusion. So far I have found mechanisms called "Compression Melting" and "Redox Melting." My question is: does anyone know any more? Thanks!
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. doodah Registered Senior Member

    Messages:
    79
    How about addition of volatiles (particularly water)?
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Fraggle Rocker Staff Member

    Messages:
    24,690
    Ice melts under compression because water is denser than ice (in all but one state anyway).
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

    Messages:
    19,227
    Ice melts under compression (as will any solid that can melt when heated) because compression is an application of force and the energy transfer heats the solid.
     
  8. Trippy ALEA IACTA EST Staff Member

    Messages:
    10,890
    Ice melts under compression because the solidus has a negative slope.

    Please Register or Log in to view the hidden image!



    Only substances that have a solidus with a negative slope will melt with increased pressure, and water is atypical in this regard. Most substances behave in the same manner as carbon dioxide:.

    Please Register or Log in to view the hidden image!



    This atypical behaviour of water is (as Fragglerocker pointed out) related to the density of the solid versus the density of the liquid, and represents an application of le chateliers's principle - namely (in this instance) that increasing the pressure on the substance pushes the equilibria in the direction of the densist state (for water, liquid, for most other substances solid).

    A well written guide aimed at people without a background in Chemistry.
     
    Last edited: Dec 7, 2009

Share This Page