Abstract
Trans Vietnam Orogenic Belt distributed in north to central Vietnam includes various types of metamorphic rocks. Most metamorphic rocks show the Permian-Triassic ages and are characterized by decompressional evolution with various metamorphic thermal gradients (8- 25 °C/km). In contrast, some metamorphic rocks having the Ordovician-Silurian age show isobaric heating prograde stage at low-pressure condition (25-30 °C/km). Granitic rocks also show the Permian-Triassic or Ordovician-Silurian ages. The older granitoids have volcanic arc chemical signature, some of which were metamorphosed at the Permian-Triassic. These results suggest that island arc tectonic setting at the Ordovician-Silurian, where arc magmatism heated the arc crust and caused the low-pressure (with isobaric heating) metamorphism at this period. The Permian-Triassic metamorphic rocks and granitoids were formed by subsequent continental collision and subduction of the Indochina craton together with the past Ordovician-Silurian island arc beneath the South China craton.
Original language | English |
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Pages (from-to) | 26-32 |
Number of pages | 7 |
Journal | Japanese Magazine of Mineralogical and Petrological Sciences |
Volume | 45 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 1 2016 |
All Science Journal Classification (ASJC) codes
- Geochemistry and Petrology
- Economic Geology