Dike propagation driven by melt accumulation at the lithosphere–asthenosphere boundary

Havlin, C.; Parmentier, E. M.; Hirth, Greg

doi:10.1016/j.epsl.2013.06.010

Cited by 78 publications

(79 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The YTVL is considered to have undergone shearing during the Cenozoic (Abebe et al, 1998), and as a result has also likely developed significant topography along its lithosphere-asthenosphere boundary, which has resulted in melt focusing (Keranen and Klemperer, 2008;Rooney et al, 2014a). Models describing the infiltration of melt into the lithospheric mantle suggest that shear is an effective mechanisms to allow for efficient transfer of magma from the asthenosphere into the lithosphere (Havlin et al, 2013). We therefore suggest that the more pronounced evidence of an underplate beneath the YTVL is the result of magma focusing along topography in the lithosphere-asthenosphere boundary, and the more efficient transit of these melts into the lithosphere by shear pathways.…”

Section: Accepted Manuscriptmentioning

confidence: 98%

“…magma reaching the lithosphere-asthenosphere boundary beneath the YTVL and/or more efficient transfer of magma into the lithosphere along the YTVL (e.g., Havlin et al, 2013). An effective mechanism for increasing magma volume at the lithosphere-asthenosphere boundary is to focus magmas generated over a wide region at a particular point.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

See 1 more Smart Citation

The making of an underplate: Pyroxenites from the Ethiopian lithosphere

et al. 2017

View full text Add to dashboard Cite

Section: Accepted Manuscriptmentioning

confidence: 98%

Section: Accepted Manuscriptmentioning

confidence: 99%

The making of an underplate: Pyroxenites from the Ethiopian lithosphere

et al. 2017

View full text Add to dashboard Cite

“…An interconnected liquid phase with a weak melt preferred orientation in a deformed matrix may also explain why some electromagnetic studies in other locations observe high conductivities but do not detect electrical anisotropy 23 . This melt distribution may arise from its accumulation at the lithosphere-asthenosphere boundary and possible upward migration through dikes that propagate buoyantly into the lithosphere 24,25 . It is also possible that asthenospheric melt percolates into the bottom of the lithosphere, eventually cooling and crystallizing.…”

Section: Letter Researchmentioning

confidence: 99%

Experimental constraints on the electrical anisotropy of the lithosphere–asthenosphere system

Pommier

Leinenweber

Kohlstedt

et al. 2015

Nature

View full text Add to dashboard Cite

The relative motion of lithospheric plates and underlying mantle produces localized deformation near the lithosphere-asthenosphere boundary. The transition from rheologically stronger lithosphere to weaker asthenosphere may result from a small amount of melt or water in the asthenosphere, reducing viscosity. Either possibility may explain the seismic and electrical anomalies that extend to a depth of about 200 kilometres. However, the effect of melt on the physical properties of deformed materials at upper-mantle conditions remains poorly constrained. Here we present electrical anisotropy measurements at high temperatures and quasi-hydrostatic pressures of about three gigapascals on previously deformed olivine aggregates and sheared partially molten rocks. For all samples, electrical conductivity is highest when parallel to the direction of prior deformation. The conductivity of highly sheared olivine samples is ten times greater in the shear direction than for undeformed samples. At temperatures above 900 degrees Celsius, a deformed solid matrix with nearly isotropic melt distribution has an electrical anisotropy factor less than five. To obtain higher electrical anisotropy (up to a factor of 100), we propose an experimentally based model in which layers of sheared olivine are alternated with layers of sheared olivine plus MORB or of pure melt. Conductivities are up to 100 times greater in the shear direction than when perpendicular to the shear direction and reproduce stress-driven alignment of the melt. Our experimental results and the model reproduce mantle conductivity-depth profiles for melt-bearing geological contexts. The field data are best fitted by an electrically anisotropic asthenosphere overlain by an isotropic, high-conductivity lowermost lithosphere. The high conductivity could arise from partial melting associated with localized deformation resulting from differential plate velocities relative to the mantle, with subsequent upward melt percolation from the asthenosphere.

show abstract

“…Gaherty et al 1996;Tan & Helmberger 2007;Rychert & Shearer 2009;Yuan & Romanowicz 2010;Fischer et al 2010). A further migration through the lithosphere occurred through dyke propagation (Havlin et al 2013). The first recorded fluid-trapping event occurred in olivines not in equilibrium with mantle composition (Fo , 89).…”

Section: Tectonics V Underplatingmentioning

confidence: 99%

Conditions for mafic magma storage beneath fissure zones at oceanic islands. The case of São Miguel Island (Azores archipelago)

Zanon

2015

View full text Add to dashboard Cite

Ponding conditions of basalts erupted from fissure zones at São Miguel Island (Azores) were investigated through microthermometry of fluid inclusions, hosted in olivines and clinopyroxenes, and whole-rock and mineral chemistry. The Região dos Picos and Achada das Furnas fissure zones formed between central volcanoes and erupted geochemically similar magmas for the last 30 kyr. Hydrocarbonic fluid inclusions that survived to diffusion and re-equilibration recorded a maximum density value of 1000 kg m 23 (29.3 km) at both fissure zones, at the intersection with the feeding systems of older central volcanoes. The maximum density decreases to 875 kg m 23 (23.5 km) towards the central segment of Região dos Picos. Further trapping of low-density fluids is occasional and limited to a few samples. While the deepest event is interpreted to mark the vertical variation of the Moho at each location, all other events are only representative of short-time ponding with fluid re-equilibration. The deepening of the Moho towards the central volcanoes might be the effect of long-lasting underplating. However, the periodic stretching of the lithosphere, in response to the differential stress field acting at central volcanoes, would have been responsible for the thinning of the crust at the central segment of the fissure zone.Supplementary material: Whole-rock geochemistry with international standard used, and representative analyses of selected mineral phases from the two segments of the Região dos Picos fissure

show abstract

Dike propagation driven by melt accumulation at the lithosphere–asthenosphere boundary

Cited by 78 publications

References 57 publications

The making of an underplate: Pyroxenites from the Ethiopian lithosphere

The making of an underplate: Pyroxenites from the Ethiopian lithosphere

Experimental constraints on the electrical anisotropy of the lithosphere–asthenosphere system

Conditions for mafic magma storage beneath fissure zones at oceanic islands. The case of São Miguel Island (Azores archipelago)

Contact Info

Product

Resources

About