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Plates vs. Plumes: A Geological Controversy
Gillian R. FoulgerDurham University, U.K.
2
Morgan (1971)The Plume Hypothesis
3
4
The Plate hypothesis
6
Predictions of the Plume Hypothesis
8Burov (2005)
1. Precursory uplift
9Coffin & Eldholm (1993)
2. Flood basalt eruption
10Campbell (2005)
3. Plume “tail” to the core-mantle boundary
11
Hawaii
4. Time-progressive chain
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5. High temperature
13
Predictions of the Plate Hypothesis
14
1. Lithospheric extension
2. Source fusibility
3. Shallow mantle source
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Plume predictions are not confirmed
Precursory uplift
Emeishan basalts, China – 260 Ma
?
Ukstins-Peate & Bryan, Nature Geoscience, 2009
Campbell,Elements, 2005
Time-progressive volcanic chains
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Hawaii
80 Ma
50 Ma
0 Ma
22
Seismology – looking for plume tails
Seismic imaging is a can of worms
Hmm… Is this a multi-headed plume?
Bruce map
Hawaii: Tomography
Li et al. (2008) Wolfe et al. (2009)
NW SE NW SE
Cao et al. (2011)
2000 km
W E
Hawaii: Receiver functions
No-one can agree onhow many plumes there are,
or where they are
Many “hot spot” lists
31Tholeiitic provinces
Ritsema & Allen (2003)Courtillot et al. (2003)
Montelli et al. (2006)
32Flood basalt & volcanic chain: only 3/49!
None fit all the predictions
33
Endless plume variants
• Lateral flow of plume material • Tabular plumes• Pulsing plumes• High 3He/4He plumes• Low 3He/4He plumes• Headless plumes• Tailless plumes
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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
This is not scientific
36
What about the Plate hypothesis?
37
The Plate hypothesis involves diverse processes
38
This immediately fits the observations
Examples
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Continental breakup
Van Wijk et al. (2001); Jones (2005)
41Silver et al. (2006)
Southern Africa
Melt ponding & draining is required
European Intraplate Volcanism
Tamar Graben?
?
??
44Beutel (2005)
Extensional stress at plate boundary junctions
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Slab tearing at Samoa
Samoa
A comment on boxing matches…
That’sall
folks