Heat sources and melting in subduction zones
نویسندگان
چکیده
منابع مشابه
Subduction Zones
[1] Subduction zones are where sediments, oceanic crust, and mantle lithosphere return to and reequilibrate with Earth’s mantle. Subduction zones are interior expressions of Earth’s 55,000 km of convergent plate margins and are the geodynamic system that builds island arcs. Excess density of the mantle lithosphere in subduction zones provides most of the power needed to move the plates while in...
متن کاملOxygen isotope evidence for slab melting in modern and ancient subduction zones
We measured oxygen isotope compositions of 34 adakites, high-Mg andesites, and lavas suspected to contain abundant slab and sediment melts from the Western and Central Aleutians, the Andes, Panama, Fiji, Kamchatka, Setouchi (Japan), and the Cascades. This suite covers much of the diversity of arc lavas previously hypothesized to contain abundant dslabT melts. Measured and calculated values of y...
متن کاملDehydration and partial melting in subduction zones: Constraints from U-series disequilibria
We present a critical reappraisal of U-series data from arc volcanoes to constrain slab dehydration and melting processes using a global subduction zone data set. There is no clear evidence for significant mobilization of Th or Pa in dehydration fluids while the source region of arc rocks is relatively oxidized and mobility of U is strongly enhanced. It is argued that along-arc U/Th and U/Pa is...
متن کاملSimple Kinematics of Subduction Zones
Two main types of subduction zones can be distinguished: (1) those where the subduction hinge migrates away from the upper plate; and (2) those in which the subduction hinge migrates toward the upper plate. Apart from a few exceptions, this distinction seems to apply particularly for W-directed subduction zones and Eor NE-directed subduction zones, respectively. Moreover, the rate of subduction...
متن کاملSome remarks on subduction zones
The rate of subduction is larger than the convergence rate along W-directed subduction zones, whereas it is smaller along Eor NE-directed subduction zones. Along Wdirected slabs, the subduction rate is the convergence rate plus the slab retreat rate, which tends to equal the backarc extension rate. Along Eor NE-directed slabs, the subduction rate is decreased by the shortening in the upper plat...
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ژورنال
عنوان ژورنال: Journal of Geophysical Research: Solid Earth
سال: 1997
ISSN: 0148-0227
DOI: 10.1029/97jb01036