Intraplate volcanism triggered by bursts in slab flux

<p><span><span>Long-lived, widespread intraplate volcanism without age progression is one of the most controversial features of plate tectonics. The eastern margin of Australia and Zealandia has experienced extensive mafic volcanism </span><span>over the last 100 million years</span><span>. A plume origin has been proposed for </span><span>three distinct chains of volcanoes,</span> <span>however</span><span>, the majority of eruptions exhibit no clear age progression. Previously proposed edge-driven convection, asthenospheric shear, and lithospheric detachment fail to explain the non age-progressive eruptions </span><span>across the </span><span>~5000 km wide intraplate volcanic province from Eastern Australia to Zealandia. We model the subducted slab volume over 100 million years and find that slab flux drives volcanic eruption frequency, indicating stimulation of an enriched mantle transition zone reservoir. Volcanic isotope geochemistry allows us to distinguish a HIMU reservoir (>1 Ga old) in the slab-poor south, from a northern EM1/EM2 reservoir, reflecting a more recent voluminous influx of oceanic lithosphere into the mantle transition zone. We provide a unified theory linking plate boundary and slab volume reconstructions to upper mantle reservoirs and intraplate volcano geochemistry.</span></span></p>

About this title - Volcanism in Antarctica: 200 Million Years of Subduction, Rifting and Continental Break-up

This memoir is the first to review all of Antarctica's volcanism between 200 million years ago and the Present. The region is still volcanically active. The volume is an amalgamation of in-depth syntheses, which are presented within distinctly different tectonic settings. Each is described in terms of (1) the volcanology and eruptive palaeoenvironments; (2) petrology and origin of magma; and (3) active volcanism, including tephrochronology. Important volcanic episodes include: astonishingly voluminous mafic and felsic volcanic deposits associated with the Jurassic break-up of Gondwana; the construction and progressive demise of a major Jurassic to Present continental arc, including back-arc alkaline basalts and volcanism in a young ensialic marginal basin; Miocene to Pleistocene mafic volcanism associated with post-subduction slab-window formation; numerous Neogene alkaline volcanoes, including the massive Erebus volcano and its persistent phonolitic lava lake, that are widely distributed within and adjacent to one of the world's major zones of lithospheric extension (the West Antarctic Rift System); and very young ultrapotassic volcanism erupted subglacially and forming a world-wide type example (Gaussberg).

Supplemental material: Geochemical study of Cenozoic mafic volcanism in the west-central Great Basin, western Nevada, and the Ancestral Cascades Arc, California

Sample locations, GPS coordinates, and geochemical data.

Supplemental material: Geochemical study of Cenozoic mafic volcanism in the west-central Great Basin, western Nevada, and the Ancestral Cascades Arc, California

Sample locations, GPS coordinates, and geochemical data.

Magma Genesis at the South Aegean Volcanic Arc

The South Aegean volcanic arc consists of five volcanic fields, with products that range from medium- and high-K calc-alkaline basalts to rhyolites. Parental magmas are generated by variable proportions of decompression and flux melting of a mantle source metasomatized by sediment melts and aqueous fluids released from the subducted slab. Fluid/sediment ratios are lowest in Santorini (Greece) where high lithospheric extension results in a predominance of decompression melting, shallower magma storage, and more mafic volcanism than elsewhere in the arc. Contributions from slab sediment melt decrease from west to east. With the lowest convergence rate and surface heat flux of any continental arc worldwide, the South Aegean is an ideal natural laboratory for studying arc magmatism at low magma production rates.