Melt Evolution above a Spontaneously Retreating Subducting Slab in a Three-Dimensional Model
نویسندگان
چکیده
Dehydration of the subducting slab favors the melting of the surrounding mantle. Water content and melt evolution atop a spontaneously retreating subducting slab are reported in a threedimensional (3-D) model. We find that fluids, including water and melts in the rocks, vary substantially along the trench, which cannot be found in two-dimensional (2-D) models. Their maxima along the subducting slab are mainly located at about 50 to 70 and 120 to 140 km. Volumetric melt production rate changes spatially and episodically atop the slab, which may reflect the intensity and variations of volcanoes.
منابع مشابه
Separation of supercritical slab-fluids to form aqueous fluid and melt components in subduction zone magmatism.
Subduction-zone magmatism is triggered by the addition of H(2)O-rich slab-derived components: aqueous fluid, hydrous partial melts, or supercritical fluids from the subducting slab. Geochemical analyses of island arc basalts suggest two slab-derived signatures of a melt and a fluid. These two liquids unite to a supercritical fluid under pressure and temperature conditions beyond a critical endp...
متن کاملThe temporal evolution of plate driving forces: Importance of slab suction versus slab pull during the Cenozoic
[1] Although mantle slabs ultimately drive plate motions, the mechanism by which they do so remains unclear. A detached slab descending through the mantle will excite mantle flow that exerts shear tractions on the base of the surface plates. This ‘‘slab suction’’ force drives subducting and overriding plates symmetrically toward subduction zones. Alternatively, cold, strong slabs may effectivel...
متن کاملMagnesian andesite in the western Aleutian Komandorsky region: Implications for slab melting and processes in the mantle wedge
The role of the subducting lithospheric slab in the genesis of mantle-derived (primitive) magmas is investigated through a study of volcanic rocks formed in the tectonically strike-slip–dominated western Aleutian arc. Two types of chemically and petrologically distinctive primitive andesites have been found among the Miocene– late Pleistocene–age volcanic rocks in the western Aleutians. These a...
متن کاملA slab in depth: Three-dimensional geometry and evolution of the Indo-Australian plate
[1] Geoscientists use plate tectonics to explain many aspects of both continental evolution and evolution of the planet as a whole. The subduction of material at convergent plate boundaries forms a fundamental component to the theory of plate tectonics. Plates, continents, subduction zones, and spreading centers all exhibit motion and geometric evolution, so to try and resolve the past geometri...
متن کاملTransient Three-Dimensional Thermal Analysis of a Slab with internal heat generation and heated by a Point Moving Heat Source
In this work, analysis of transient three-dimensional heat transfer in a slab with internal heat generation and heated by a point moving heat source along its axis is carried out using integral transforms methods. The heat input into slab or workpiece by the moving heat source is considered in the model. From the results, it was established that the temperature of the material during the heat t...
متن کامل