igmet final

• How do we know earth has layers?

  seismic tomography
• how do we know of earth's composition?

  meteorites
• What earthly rocks are closest to chondritic meteorites?

  peridotites
• lithophile


  rock-loving
• siderophile


  iron-loving
• chalcophile


  sulfide-loving
• kimberlite


  a bunch of xenoliths
• xenolith


  fragment of rock from the crust and upper mantle carried near the surface through volcanic eruptions
• volatile


  substances easily evaporated
• heat sources in earth

  early accretion, radioactive breakdown
• heat transfer

  radiation, conduction, convection, advection
• abyssal peridotites

  MORBs
• primary minerals


  directly crystallized from melt
• secondary melt


  anything formed after
• viscosity is inversely proportional to diffusion rate of ions
• gibb's free energy decreases as temperature increases
• gibb's phase rule

  F=1 on phase change lines, F=2 anywhere, F=0 on eutectic and peritectic point
• the last melt to crystallize and the first to melt is the eutectic point
• dry melting


  MORBs
• wet melting


  IABs
• hot-spots

  OIBs
• pahoehoe


  ropy lava
• aa


  clumpy lava
• pillow


  lava under water
• volcanic eruptions

  hawaiian, strombolian, vulcanian, plinian, pelean, caldera
• volcanic products(tephra)

  ash, lapilli, bombs, pumice
• volcanic architecture

  caldera, composite, fissure, cinder cones
• lithophiles are in the crust because they are highly compatible to fluid phase
• chondrites are igneous, because they form with no pressure
• polymerization


  molecule size
• ways to classify igneous rocks

  composition, texture, mineralogy
• peridotite are made through

  adiabetic melting
• sources of mantle

  ophiolites, dredge samples, nodules, xenoliths, kimberlites
• fertile mantle

  lherzolite
• positive clapeyron slope

  volume and entropy is positive (ice->vapor)
• how to melt mantle?

  increase temp, decrease pressure, add volatiles
• komatiite


  very hot ultramafic melts that formed in the Archean
• magma differentiation processes

  create a compositional difference, preserve the chemical difference
• RCMP

  1% = permeable and interconnected network
• fractional crystallization


  melt will evolve to low Ca, Mg, Fe but high Na, K; more felsic