Derivation of some modern arc magmas by melting of young subducted lithosphere

  title={Derivation of some modern arc magmas by melting of young subducted lithosphere},
  author={Marc J. Defant and Mark S. Drummond},
MOST volcanic rocks in modern island and continental arcs are probably derived from melting of the mantle wedge, induced by hydrous fluids released during dehydration reactions in the subducted lithosphere1. Arc tholeiitic and calc-alkaline basaltic magmas are produced by partial melting of the mantle, and then evolve by crystal fractionation (with or without assimilation and magma mixing) to more silicic magmas2—basalt, andesite, dacite and rhyolite suites. Although most arc magmas are… 
Geochemical evidence for the melting of subducting oceanic lithosphere at plate edges
Geochemical data from the Kamchatka peninsula and the Aleutian islands are presented that reaffirms the slab-melt interpretation of adakites, but in the tectonic context of the exposure to mantle flow around the edge of a torn subducting plate.
Igneous Rock Associations 8. Arc Magmatism II: Geochemical and Isotopic Characteristics
Geochemical and isotopic data provide insights into the origin and evolution of magmatism found at destructive plate margins. Tholeiitic magmas are dominant in the early stages of oceanic island-arc
Lithospheric mantle, asthenosphere, slab and crustal contribution to petrogenesis of Eocene to Miocene volcanic rocks from the west Alborz Magmatic Assemblage, SE Ahar, Iran
Abstract Significant uncertainty remains regarding the exact timing and nature of subduction events during the closure of the Tethyan seas in what is now NW Iran. This study thus presents new
The Cretaceous Separation Point batholith, New Zealand: granitoid magmas formed by melting of mafic lithosphere
The Early Cretaceous Separation Point batholith of the South Island, New Zealand, represents the final magmatic stage of an extensive arc system located on the SW Pacific margin of Gondwana during
Transition from calc-alkalic to adakitic magmatism at Cayambe volcano, Ecuador: Insights into slab melts and mantle wedge interactions
In volcanic arcs, two main types of magmatism are recognized: (1) widespread calc-alkalic magmatism, generated by hydrous partial melting of a metasomatized mantle wedge, and (2) less common adakitic
Oceanic Slab Melting and Mantle Metasomatism
Modern slab melts are thus unlike Archean Trondhjemite–Tonalite–Granodiorite rocks (TTG), which suggests that both types of magmas were generated via different petrogenetic pathways which may imply an Archean tectonic model of crust production different from that of the present-day, subduction-related, one.


Volcanic Arc Magmas: Implications of a Melting-Mixing Model for Element Recycling in the Crust-Upper Mantle System
  • R. Kay
  • Geology
    The Journal of Geology
  • 1980
A multicomponent melting-mixing model for the origin of volcanic arc basalt magmas implies signifi cant recycling of K, Rb, Ba, and other elements in the crust-upper mantel system. The model accounts
Effect of steeper Archean geothermal gradient on geochemistry of subduction-zone magmas
The comparative study of Archean and post-Archean granitic rocks shows significant changes with time. The high rare-earth element fractionation and the low Yb content of the Archean granitoids
Petrogenesis of Mount St. HElens dacitic magmas
The most frequent and voluminous eruptive products at Mount St. Helens are dacitic in composition, although a wide variety of magma types (basalt to rhyodacite) is represented. To address the
Geochemistry of Holocene volcanic rocks associated with ridge subduction in Baja California, Mexico
Although the geochemistry of magmatism associated with the subduction of oceanic lithosphere is well understood1–6, the geochemical signature of lavas produced shortly after subduction of an oceanic
REE-fractionated trachytes and dacites from Papua New Guinea and their relationship to andesite petrogenesis
Minor trachyte and dacite temporally associated with, but spatially separated from, arc-trench type volcanoes in Papua New Guinea have distinctive REE abundances similar to experimentally produced
The origin of low-K rhyolites from the mariana frontal arc
Low-K rhyolites and overlying 2-pyroxene andesites, both of Late Eocene age, comprise the oldest volcanic units exposed on Saipan. The mineralogy and geologic setting of these rocks indicate they
Petrology of amphibolite-facies mafic and ultramafic rocks from the Catalina Schist, southern California: metasomatism and migmatization in a subduction zone metamorphic setting
The Catalina Schist of southern California is a subduction zone metamorphic terrane. It consists of three tectonic units of amphibolite-, high-P greenschist- and blueschist-facies rocks that are