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Session Dinner

Zur Alten Kaisermühle Restaurant,Alte Donau, Fischerstrand 21A

7.45 pm tonightPayment: Cash at the restaurant

(no credit cards)

Meeting point:We will set off for the restaurant at 7.15 pm from

this room (24)

Challenges to Plume and Plate – Telling it like it is

Gillian R. Foulger University of Durham, UK

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Definition of a “plume”• fossil plume (Rotolo et al., 2006)• dying plume (Davaille & Vatteville, 2005)• recycled plume head (Gasperini et al., 2000)• tabular plume (Hoernle et al., 1995)• finger-like plume (Cadoux et al., 2007)• baby plume (Ritter, 2006)• channelled plume (Oyarzun et al, 1997)• toroidal plume (Mahoney et al., 1992)• head-free plume (Ritter, 2006)• cold plume (Hanguita & Hernan, 2000)• depleted residual plume (Danyushevsky et al., 1995)• pulsating plume (Krienitz et al., 2007)• subduction fluid-fluxed refractory plume (Falloon et

al., 2007)

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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Comparison with geosynclines• Mio-geosyncline• Eu-geosyncline• Ortho-geosyncline• Primary geosyncline• Zeugo-geosyncline• Para-geosyncline• Exo-geosyncline• Taphro-geosyncline• Paralia-geosyncline

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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Basic observations

Large amounts of compositionally distinct magma

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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Composition

The bottom line:

Geochemistry (FOZO, C, PHEM etc.) does NOT require a lower-

mantle source

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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Volume

The primary observable

But it often cannot be explained – by plumes, or other mechanisms

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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Volume

Cordery et al. (1997)

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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Volume

Van Wijk, 2001

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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Temperature

Are “hot spots” hot?

What evidence is there for high T?

Petrology?

Seismology?

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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Temperature

Herzberg et al., 2007

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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Temperature

Korenaga, 2004

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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How can it help us?

Can it help us?

• Major problems:– Repeatability poor– Poor data coverage globally– Interpretation ambiguous

Seismic tomography• Definition of

“plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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Seismology

Comment of van der Hilst & de Hoop (2005) on “plumes” identified by “banana-doughnut tomography”

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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• Velocity dependent on:– Phase (mineral or state)– Composition– Temperature

Seismology

RED = HOT

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

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Summary

The bottom line:

Fundamental problems to address

Lots of methods available

But serious difficulties that should not be ignored

• Definition of “plume”

• Composition

• Volume

• Temperature

• Seismology

• Summary

That’s all folks