Synthesis

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Synthesis

• Gillian R. Foulger

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Post-meeting books?

• Book of review articles
• Chemical Geology (Elsevier)
• AGU monograph
• Book of regular papers

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• Everyone is invited to contribute to
• www.mantleplumes.org

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Key points 1

• Alternatives do not amount to a single, generic,
  one-size fits all replacement model for plume
• generic elements, but each locality individual,
  e.g., OJP, Hawaii, Azores

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Key points 2

• Consistent terminology imperative
• Use of properly defined/explained terms.
• It isnt enough to just say plume
• Problem of falsification

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Key points 3

• 1,000-km-wide magmatism - predicted by both?
• Time-progressive track - predicted by both?
• Uplift. Domal? - complex pattern predicted by
  both?
• Temperature - necessary?
• CMB origin - detectable?

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Key points 4

• Opinion of relationship between plate tectonics
  plumes.

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Key points 5

• Problems with publications
• Standard of interpretations (cart before horse)
• Repetition of old, wrong data e.g. ages,
  temperatures.

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Important problems 1

• Mantle physics
• Self-consistent models that can produce plate
  tectonics required.
• Better understanding of critical mantle physical
  parameters, e.g. CMB heat flow, LM viscosity
• How important is small-scale convection?

• Lithosphere physics
• Behaviour of lithosphere when major thermal event
  occurs - plume, delamination, rifting, meteorite?
  
• Response of lithosphere to stress - cracking?
• Characterise lithospheric stress
• What causes rifting?

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Important problems 2

• Temperature
• Petrological temperatures
• Phase equilibrium of CO2-bearing systems
• Melting at all depths
• other geothermometry methods e.g. seismological

• Geochronology
• More high-quality dates
• Re-date important chains where old dates
  inadequate.
• LIP ages. Can we be more specific?

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Important problems 3

• Seismology
• Interpreting mantle seismic anomalies in the
  mantle and D - hot? cool? buoyant? dense?
• Very wide seismic tomography?
• Transfer of material between UM LM?
• Are innovative high-resolution experiments
  feasible?

• Planetary
• Sort out Venus.
• Look for meteorite evidence in geology.

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Important problems 4

• Field evidence
• Make diagnostic observations, e.g., uplift??
  temperature, mantle structure.
• Potential plume localities?
• Can we distinguish cause and effect, e.g. rifting
  volcanism?
• Address problems of the Emperor-Hawaii system.

• Petrology Geochemistry
• Improved melt generation models needed
• Melting high-P trace-element partition
  coefficients needed
• Where/what is/are the OIB sources?