How plumes help to break plates

Buiter, Susanne

doi:10.1038/513036a

Cited by 12 publications

(8 citation statements)

References 11 publications

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“…Yet the generation of ocean floor in the South Atlantic only began after the plume head eruption. Therefore, it is possible that the extension of continents concentrates above mantle plumes, which thus may assist in continental breakup [ Buiter , ; Burov and Gerya , ].…”

Section: Motivationmentioning

confidence: 99%

Major influence of plume‐ridge interaction, lithosphere thickness variations, and global mantle flow on hotspot volcanism—The example of Tristan

Gassmöller

Dannberg

Bredow

et al. 2016

Geochem Geophys Geosyst

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Hotspot tracks are thought to originate when mantle plumes impinge moving plates. However, many observed cases close to mid-ocean ridges do not form a single age-progressive line, but vary in width, are separated into several volcanic chains, or are distributed over different plates. Here we study plume-ridge interaction at the example of the Tristan plume, which features all of these complexities. Additionally, the South Atlantic formed close to where plume volcanism began, opening from the south and progressing northward with a notable decrease in magmatism across the Florianopolis Fracture Zone. We study the full evolution of the Tristan plume in a series of three-dimensional regional models created with the convection code ASPECT. We then compute crustal thickness maps and compare them to seismic profiles and the topography of the South Atlantic. We find that the separation of volcanism into the Tristan and Gough chain can be explained by the position of the plume relative to the ridge and the influence of the global flow field. Plume material below the off-ridge track can flow toward the ridge and regions of thinner lithosphere, where decompression melting leads to the development of a second volcanic chain resembling the Tristan and Gough hotspot tracks. Agreement with the observations is best for a small plume buoyancy flux of 500 kg/s or a low excess temperature of 150 K. The model explains the distribution of syn-rift magmatism by hot plume material that flows into the rift and increases melt generation.

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Section: Motivationmentioning

confidence: 99%

Major influence of plume‐ridge interaction, lithosphere thickness variations, and global mantle flow on hotspot volcanism—The example of Tristan

Gassmöller

Dannberg

Bredow

et al. 2016

Geochem Geophys Geosyst

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“…Extensive volcanism and tectonic activity in the East African Rift system (EARS) are regarded as the classic example of present-day plume-related rifting and continental breakup 1–3 . Rifting began in southern Ethiopia at approximately 45 Ma 4 with volcanism in northern Ethiopia and Yemen starting ∼30 Ma 5 .…”

Section: Introductionmentioning

confidence: 99%

Superplume mantle tracked isotopically the length of Africa from the Indian Ocean to the Red Sea

et al. 2019

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Seismological findings show a complex scenario of plume upwellings from a deep thermo-chemical anomaly (superplume) beneath the East African Rift System (EARS). It is unclear if these geophysical observations represent a true picture of the superplume and its influence on magmatism along the EARS. Thus, it is essential to find a geochemical tracer to establish where upwellings are connected to the deep-seated thermo-chemical anomaly. Here we identify a unique non-volatile superplume isotopic signature (‘C’) in the youngest (after 10 Ma) phase of widespread EARS rift-related magmatism where it extends into the Indian Ocean and the Red Sea. This is the first sound evidence that the superplume influences the EARS far from the low seismic velocities in the magma-rich northern half. Our finding shows for the first time that superplume mantle exists beneath the rift the length of Africa from the Red Sea to the Indian Ocean offshore southern Mozambique.

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“…In order to conserve energy, initial rifting sites within continental crust are often spatially associated with pre-existing ‘structural heterogeneities’ such as suture zones related to ancient orogenic boundaries or regions of the crust with differential thickness 2 5 6 7 . A given ‘structural heterogeneity’ may be exploited by either a mantle-plume (active extension) or a regional stress field (passive extension) associated with plate boundary forces (slab-pull) that becomes a focal point for flood basalt volcanism before developing into an ocean basin 8 . Moreover, icosahedral structures with triple-junction configuration form quasi-hexagonal fractures that minimize the total boundary length and produce polyhedral plate configurations, thus minimizing the energy, area, work and stress required to brittely break plates 9 10 .…”

mentioning

confidence: 99%

The initial break-up of Pangæa elicited by Late Palæozoic deglaciation

Yeh

Shellnutt

2016

Sci Rep

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The break-up of Pangæa was principally facilitated by tensional plate stress acting on pre-existing suture zones. The rifting of Pangæa began during the Early Permian along the southern Tethys margin and produced the lenticular-shaped continent known as Cimmeria. A mantle-plume model is ascribed to explain the rift-related volcanism but the NW-SE oriented Cimmerian rifts do not correlate well with pre-existing suture zones or ‘structural heterogeneities’ but appear to have a pertinent spatial and temporal association with Late Palæozoic glacial-interglacial cycles. Mantle potential temperature estimates of Cimmerian rift-related basalts (1410 °C ± 50 °C) are similar to ambient mantle conditions rather than an active mantle-plume rift as previously suggested. Moreover, we find that the distribution of glacial deposits shows significant temporal and spatial concurrence between the glacial retreat margins and rifting sites. We conclude that the location and timing of Cimmerian rifting resulted from the exploitation of structural heterogeneities within the crust that formed due to repeated glacial-interglacial cycles during the Late Palæozoic. Such effects of continental deglaciation helped to create the lenticular shape of Cimmeria and Neotethys Ocean suggesting that, in some instances, climate change may directly influence the location of rifting.

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How plumes help to break plates

Cited by 12 publications

References 11 publications

Major influence of plume‐ridge interaction, lithosphere thickness variations, and global mantle flow on hotspot volcanism—The example of Tristan

Major influence of plume‐ridge interaction, lithosphere thickness variations, and global mantle flow on hotspot volcanism—The example of Tristan

Superplume mantle tracked isotopically the length of Africa from the Indian Ocean to the Red Sea

The initial break-up of Pangæa elicited by Late Palæozoic deglaciation

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