island arc


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Related to island arc: rift valley

island arc

[′ī·lənd ¦ärk]
(geography)
A group of volcanic islands, usually situated in a curving arch-like pattern that is convex toward the open ocean, having a deep trench or trough on the convex side and usually enclosing a deep basin on the concave side; formed by volcanic activity associated with oceanic plate subduction at convergent plate margins. Also known as volcanic arc.
References in periodicals archive ?
Negative Nb and positive Sr anomalies indicate island arc type tectonic setting.
Compared with depleted high-field-strength elements, they show notable characteristics of depleted Nb and Ta, which is similar to that of island arc magmatite in subduction zone; both of their mineral compositions are generally consistent with those of amphibole calc-alkaline granitoid (ACG) under the mechanism of subduction (Lei et.
Hayasaka, "Genesis and evolutional processes of the Paleozoic oceanic island arc crust, Asago body of the Yakuno ophiolite, southwest Japan," Journal of the Geological Society of Japan, vol.
In Basaltic Volcanism Associated with Extensional Tectonics in the Taiwan-Luzon Island Arc: Evidence for Non-depleted Sources and Subduction Zone Enrichment (ed.
Taken together, the evidence suggests that 50 million years ago, India collided with an island arc, pushing it northward.
In all the above-mentioned four sets of new discriminant function based tectonomagmatic diagrams, there is no differentiation between the continental and oceanic arc settings, and the entire arc setting is represented by island arc setting (IAB).
Farhoudi [5], introduce 3subdivision for Zagros based on similarity that exist between Zagros and island arc:
1982: Petrogenesis of the island arc tholeiite series of the South Sandwich Islands.-- University of Leeds, U.K.
Eighteen contributed chapters honoring Windley's influence are arranged in sections on oceanic and island arc systems and continental growth, the tectonics of accretionary orogens and continental growth, growth and stabilization of continental crust (collisions and intraplate processes), Precambrian tectonics and the birth of continents, and active tectonics and geomorphology of continental collision and growth zones.
Systematic changes in the distribution of some oxides in the profile from the continent towards the island arc across the Philippine Sea can be stated: CaO and S[O.sub.3] contents increase while [K.sub.2]O/[Na.sub.2]O ratio decreases, evidently as the influence of terrigenous contribution became weaker.
Pinet and Tremblay (1995) proposed that emplacement of the Quebec ophiolites was caused by the collision of an island arc with the North American continent during the Ordovician.
1, Sumatera is like other islands of Indonesia, representing and island arc where the formation was related to the activity of subduction zone.