2 1971 : “plume” 3 4 predictions 5 1. precursory uplift burov (2005)
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2
1971 : “Plume”
3
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4
Predictions
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1. Precursory uplift
Burov (2005)
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2. LIP eruption
Coffin & Eldholm (1993)
7Campbell (2005)
3. “Tail” to core-mantle boundary
8
Hawaii
4. Time-progressive chain
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5. High temperature
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Plate
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The Plate hypothesis
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Predictions
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Lithospheric extension
Source fusibility
Shallow mantle source
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Many scientists beginning to doubt Plume and swing towards
Plate
Why?
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Observations do not fit Plume predictions
Examples
No-one can agree onhow many plumes there are, or
where they are
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Many “hot spot” lists
19Flood basalt & chain: only 3/49!
None fit all the predictions
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Some spectacular disagreements
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Hawaii
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Endless plume variants• Lateral flow of plume material • Tilted plumes• Pulsing plumes• Low 3He/4He plumes• High 3He/4He plumes• Headless plumes• Tailess plumes• Ridge-captured plumes• Ridge-escaping plumes
This is not scientific!
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What about Plate?
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The Plate hypothesis involves diverse processes
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IT IS**NOT**
ONE–SIZE–FITS–ALL
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This immediately fits observations
What are these diverse processes?
Examples
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1. Continental breakup
Van Wijk et al. (2001); Jones (2005)
31Korenaga (2005)
Ontong
Java
Plateau
2. Fertility at mid-ocean ridges
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400 Ma
Today
400 Ma
Iceland
33Beutel (2005)
ExamplesBouvet triple junction
Azores triple junction
Easter microplate
3. Extensional stress at plate boundary junctions
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Iceland V-shaped ridges
Hey et al. (2010)
36Ferrari (2004)
4. Slab tearing & breakoff
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Slab tearing at Samoa
Samoa
38Cordery et al. (1997)
• eclogite
• Latent heat of fusion = 0
T = 200 K
• Lithosphere age = 6.25 Ma
• Max volume rate 0.8 x 106 km3/Ma
5. The issue of volume
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Silver et al. (2006)
Southern Africa
Melt ponding & draining
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Sublithospheric melt ponding & draining
That’s
allfolks
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