Timing of metamorphism and formation of garnet granite in the Kontum Massif, central Vietnam: Evidence from monazite EMP dating
Timing of metamorphism and formation of garnet granite in the Kontum Massif, central Vietnam: Evidence from monazite EMP dating
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DOI：
10.2465/jmps.060617a
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发表时间：
2006-12
影响因子：
0.7
通讯作者：
M. Owada;Y. Osanai;T. Hokada;N. Nakano
中科院分区：
文献类型：
--
作者：
M. Owada;Y. Osanai;T. Hokada;N. Nakano
含石榴子石花岗岩（Grt花岗岩）和高级泥质片麻岩产于越南中部Kontum地块南部的Kannak杂岩中。电子探针（EMP）测年的Grt花岗岩和石榴石斜方辉石片麻岩（Grt-Opx片麻岩）中的独居石年龄约为2000年。260 Ma的核心和约。230 Ma来自薄边缘。由于大多数独居石颗粒主要是核心组成，约。260 Ma年龄指示了高温变质作用和花岗岩形成的时间。花岗岩体局部伴有同时代的细粒辉长岩侵入，是晚二叠世地壳高级变质和部分熔融的热源候选者。
Garnet-bearing granite (Grt-granite) and high-grade pelitic gneisses occur in the Kannak Complex, southern Kontum Massif, central Vietnam. Electron microprobe (EMP) dating of monazite in Grt-granite and garnet-orthopyroxene gneiss (Grt-Opx gneiss) gave ages of ca. 260 Ma from cores and ca. 230 Ma from thin rims. Since most monazite grains are predominately of core composition, the ca. 260 Ma age indicates the timing of high-temperature metamorphism and the formation of Grt-granite. Grt-granite is locally accompanied by coeval intrusions of fine-grained gabbro, which is a candidate for the heat source leading to high-grade metamorphism and partial melting of the crust during the Late Permian.