Syncollisional rapid granitic magma formation in an arc-arc collision zone: Evidence from the Tanzawa plutonic complex, Japan
Syncollisional rapid granitic magma formation in an arc-arc collision zone: Evidence from the Tanzawa plutonic complex, Japan
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DOI：
10.1130/g30526.1
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发表时间：
2010-03
期刊：
影响因子：
5.8
通讯作者：
K. Tani;D. Dunkley;J. Kimura;R. Wysoczanski;Kunimi Yamada;Y. Tatsumi
中科院分区：
文献类型：
--
作者：
K. Tani;D. Dunkley;J. Kimura;R. Wysoczanski;Kunimi Yamada;Y. Tatsumi
日本中部的坦泽岩体（TPC）是一套暴露在全球独特的弧-弧碰撞带上的调质-辉长岩，在这里，一个活跃的洋内伊豆-波宁-马里亚纳（IBM）弧与本州弧碰撞。TPC被广泛认为是IBM弧的一个暴露的中地壳剖面，这主要是因为TPC与IBM弧岩石的地球化学相似性以及之前报道的碰撞前中新世K-Ar年龄。新的锆石U-Pb年龄表明，TPC岩浆活动的主脉冲为同碰撞，岩体在上新世碰撞后迅速就位并迅速冷却。TPC锆石微量元素的Th/Nb比值明显高于其他非碰撞IBM硅质深成岩锆石，表明其岩浆成因中有本州弧陆相沉积物的参与。
The Tanzawa plutonic complex (TPC), central Japan, is a suite of tonalitic-gabbroic plutons exposed in a globally unique arc-arc collision zone, where an active intraoceanic Izu-Bonin-Mariana (IBM) arc is colliding against the Honshu arc. The TPC has been widely accepted as an exposed middle crust section of the IBM arc, chiefly because of geochemical similarities between the TPC and IBM rocks and previously reported precollisional Miocene K-Ar ages. However, new zircon U-Pb ages show that the main pulse of TPC magmatism was syncollisional and that plutons were emplaced rapidly and cooled soon after Pliocene collision. Trace element compositions of TPC zircon show distinctively elevated Th/Nb ratios compared to zircon from other noncollisional IBM silicic plutonic rocks, indicating the involvement of continental sediments from the Honshu arc in their magma genesis.