Partial melting 3. Migmatites and melt extraction.

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Partial melting 3. Migmatites and melt extraction

Transcript of Partial melting 3. Migmatites and melt extraction.

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Partial melting

3. Migmatites and melt extraction

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Partially molten rocks

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MESOSOME = Not melted

LEUCOSOME = Liquid = granitic magma

MELANOSOME = Residue

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Biot

Plg

QzKF

Biot

Plg

Qz KF

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MetatexitesDiatexites

« Dirty » granites

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Rhéologie des roches partiellement fondues

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Melt extraction

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Brown, 1994

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Melt depletion

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An experimental study of melt extraction

J. Barraud, PhD 2000

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(Films)

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Films 2

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Evolution de la déformation1) 5% de raccourcissement

2) 22% de raccourcissement

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4) 36% de raccourcissement

3) 30% de raccourcissement

Le pli devient asymétrique et un des flancs évolue en zone de cisaillement.

La distribution hétérogène du liquide permet de localiser la déformation.

Zone de cisaillement

Bande de cisaillement

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Melt extraction: role of deformation

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Burg et al., 1994

Melting and migmatitic domes – migmatites in orogenic belts

The Velay dome

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