5.9 Hot Spots and Large Igneous Provinces

Bachèlery, Patrick; Villeneuve, Nicolas

doi:10.1016/b978-0-12-374739-6.00084-1

Cited by 7 publications

(2 citation statements)

References 155 publications

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“…b -Cone distribution for the rift zones related to the deep and shallow plumbing systems of Piton de la Fournaise, during the post-shield stage of Mauna Kea (data from Kervyn et al, 2012) and at Mount Etna (data from Wadge, 1977;Neri et al, 2011). adjustments associated with plate movements, (2) lithospheric adjustments related to the load of the edifice, (3) stresses imposed by the southward flank spreading, and/or (4) stresses related to the magma conduit caused by overpressure or conduit-related disturbances of regional stresses. In the case of Piton de la Fournaise, factors 1 and 3 probably have a very little influence since the African plate moves much more slowly than the Pacific plate (~2 cm/yr for La Réunion and 7-10 cm/yr in Hawaii relative to the hotspot referential; Müller et al, 1993;Gripp and Gordon, 2002;Bachèlery and Villeneuve, 2013) and only old events of major flank spreading have been identified and confined to the Piton des Neiges edifice (Le Friant et al, 2011). Contrary to Hawaii, the lithosphere below La Réunion does not show any downward flexure .…”

Section: Geometry Of the Plumbing Systemmentioning

confidence: 98%

Rift zones and magma plumbing system of Piton de la Fournaise volcano: How do they differ from Hawaii and Etna?

Michon

Ferrazzini

Muro

et al. 2015

Journal of Volcanology and Geothermal Research

122

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International audienceOn ocean basaltic volcanoes, magma transfer to the surface proceeds by subvertical ascent from the mantle lithosphere through the oceanic crust and the volcanic edifice, possibly followed by lateral propagation along rift zones. We use a 19-year-long database of volcano-tectonic seismic events together with detailed mapping of the cinder cones and eruptive fissures to determine the geometry and the dynamics of the magma paths intersecting the edifice of Piton de la Fournaise volcano. We show that the overall plumbing system, from about 30 km depth to the surface, is composed of two structural levels that feed distinct types of rift zones. The deep plumbing system is rooted between Piton des Neiges and Piton de la Fournaise volcanoes and has a N30–40 orientation. Above 20 km below sea level (bsl), the main axis switches to a N120 orientation, which permits magma transfer from the lithospheric mantle to the base of the oceanic crust, below the summit of Piton de la Fournaise. The related NW-SE rift zone is 15 km wide, linear, spotted by small to large pyroclastic cones and related lava flows and emits slightly alkaline magmas resulting from high-pressure fractionation of clinopyroxene ± olivine. This rift zone has low magma production rate of ~ 0.5–3.6 × 10 −3 m 3 s −1 and an eruption periodicity of around 200 years over the last 30 ka. Seismic data suggest that the long-lasting activity of this rift zone result from regional NNE-SSW extension, which reactivates inherited lithospheric faults by the effect of underplating and/or thermal erosion of the mantle lithosphere. The shallow plumbing system (b11 km bsl) connects the base of the crust with the Central Cone. It is separated from the deep plumbing system by a relatively large aseismic zone between 8 and 11 km bsl, which may represent a deep storage level of magma. The shallow plumbing system feeds frequent, short-lived summit and flank (NE and SE flanks) eruptions along summit and outer rift zones, respectively. Summit rift zones are very active (~0.1–0.25 m 3 s −1), short (2–3 km), and present an orthogonal pattern confined to the central active cone of Piton de la Fournaise. Outer NE and SE rift zones are much less active (~4–7.3 × 10 −3 m 3 s −1) and extend from inside the Enclos Fouqué caldera to bound the mobile eastern volcano flank. We show that the outer rift zones are almost aseismic and are genetically linked to the seaward flank displacements, whose most recent events where detected in 2004 and 2007. East flank sliding is itself triggered by shallow (b 2 km depth) sill intrusions. We propose that the subvertical magma intrusions along the perpendicular summit rift zones, sill intrusions, and subsequent magma injections along the outer rift zones are controlled by cycles of stress permutations. We thus tentatively propose that as for Piton de la Fournaise, the regional stress field acting on Etna and Hawaiian volcanoes is an important parameter in the control of the magma transfer along their deep plumbing system whereas the dyna...

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Section: Geometry Of the Plumbing Systemmentioning

confidence: 98%

Rift zones and magma plumbing system of Piton de la Fournaise volcano: How do they differ from Hawaii and Etna?

Michon

Ferrazzini

Muro

et al. 2015

Journal of Volcanology and Geothermal Research

122

View full text Add to dashboard Cite

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“…The oldest Piton des Neiges products (before 2.4 Ma up to 0.43 Ma) are basaltic in composition, dominated by olivine-bearing basalts and olivine-rich oceanites. They have been emplaced during periods of high effusion rate, corresponding to the shield-building stage of the volcano (Bachèlery and Villeneuve, 2013). The activity ended with the emplacement of more alkaline and differentiated products, ranging in composition from alkali basalts to quartz-bearing trachytes (Nativel, 1978;Gillot and Nativel, 1982;Haurie, 1987;Rocher, 1988aRocher, , 1988bRocher, , 1990Bret et al, 2003).…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Turbidity current activity along the flanks of a volcanic edifice: The Mafate volcaniclastic complex, La Réunion Island, Indian Ocean

Mazuel

Sisavath²,

Babonneau

et al. 2016

Sedimentary Geology

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International audienceRecent marine geophysical surveys reveal the existence of well-developed volcaniclastic deep-sea fans around La Réunion Island, Indian Ocean. The Mafate turbidite complex, located in the northwestern part of the island, is a large sedimentary system formed by two coalescent-like volcaniclastic deep-sea fans: the Mafate fan and the Saint-Denis fan. They are both connected to terrestrial rivers supplying sediment produced by erosion on the island, particularly during austral summer cyclonic floods. Through the integration of marine geophysical data (including bathymetry, backscatter multibeam sounder images, TOBI side-scan sonar images and seismic reflection profiles) and piston cores, a submarine morpho-sedimentary map of the surface architecture of the Mafate and Saint-Denis turbidite systems has been established. The systems are divided in three main domains: deep canyons in the proximal area, a channel network in the medial area, and distal depositional lobes on the abyssal sea floor. Two large sediment wave fields also formed as a result of the volcaniclastic turbidity currents. Three piston cores collected along the Mafate complex provide information on the sedimentary processes in this area over the last 25 ka. The record of turbidite events in these cores is interpreted in terms of volcanic and climatic changes that could have controlled the sediment transfer to the deep ocean

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