Project's information

Project's title Metamorphic evolution of the Kontum Massif during Ordovician–Silurian
Project’s code GUST.STS.ĐT2020-KHTĐ02
Research hosting institution Graduate University of Science and Technology
Project leader’s name Dr. Bui Thi Sinh Vuong
Project duration 01/09/2020 - 30/09/2022
Project’s budget 300 million VND
Classify Excellent
Goal and objectives of the project

- Identifying and zoning the Ordovician–Silurian metamorphic and magmatic rocks in the Kontum Massif;
- Determining of P–T conditions of Ordovician–Silurian metamorphic rocks;
- Revealing the metamorphic history of the Kontum Massif and the southern Truong Son belt during Ordovician–Silurian period by constructing the P–T–t path for the Ordovician–Silurian metamorphic rocks of each metamorphic complexes in the study area.

Main results

- Theoretical results:
The metamorphic history of the study area is constrained as follows: The metamorphic rocks in the Kannack Complex experienced the high to ultrahigh temperature metamorphism during Permian–Triassic. The the climax condition was identified between ca. 250–265 Ma, followed by a retrograde metamorphic phase at ~250 Ma. Finally, the intense hydration associated with the formation of the secondary minerals such as muscovite and chlorite took place at ca. 230 Ma. Two high-temperature metamorphic phases including the Ordovician–Silurian (~ 430–450 Ma) with the prograde stage occurred at ~ 440–450 Ma and Permian–Triassic (~ 240–250 Ma) of which the metamorphic conditions of granulite facies were achieved during ~ 240–250 Ma, subsequently decompression during retrograde metamorphism were recorded in the Ngoc Linh metamorphic rocks. The garnet–kyanite–biotite pelitic gneisses are only affected by the Permian–Triassic medium pressure metamorphic phase at ~230–240 Ma, which is consistent with the youngest detrital zircon age of ~250 Ma. The high-temperature metamorphic stage (sillimanite field) at ca. 430–440 Ma, followed by a retrograde metamorphic phase (kyanite field) at ~ 410–420 Ma were revealed from the Dai Loc metamorphic rocks. The mylonitic granite intrusive rocks were formed by partial melting of the host gneiss pelite at ~ 430 Ma. 
- Applied results:
+ Behavior of zircon–monazite–garnet in the different metamorphic conditions is possible to directly apply to other metamorphic rock regions in the world in order to interpret the metamorphic petrographic features and metamorphic history of those area.
+ Uderstanding the metamorphic and tectonic history during Ordovician–Silurian and Permian–Triasic of the study area is an important premise for examining the tectonic history of Southeast Asia and Asia during Early Paleozoic–Early Mesozoic in particular, and the material composition and development history of the lithosphere in general when expanding research to other regions, especially along plate margins. This is also basic foundation to investigate more deeply on geodynamic processes, combined with paleomagnetic and paleontological data to constrain the model of continental converging and spreading processes.

Novelty and actuality and scientific meaningfulness of the results

- This project has provided a reliable set of data on petrographic features, geochemistry of major and trace elements and isotopic ages analyzed by advanced methods with high accuracy of magmatic and metamorphic rocks in the Kannak, Ngoc Linh and Kham Duc and Dai Loc complexes.
- Integrated with previous results, the outcomes of this study have provided the detailed insights into the metamorphic history and tectonics of the Ordovician–Silurian and Permian–Triasic phases in the Kannack, Ngoc Linh, Kham Duc metamorphic complexes (Kontum Massif) and Dai Loc complex (Truong Son belt).

Products of the project

- Scientific papers in referred journals (list):
+ 01 ISI paper: Vuong Bui Thi Sinh, Yasuhito Osanai, Nobuhiko Nakano, Ippei Kitano, Tatsuro Adachi, Anh Tran Tuan, Binh Pham, 2022. Petrology and zircon U–Pb geochronology of pelitic gneisses and granitoids from the Dai Loc Complex in the Truong Son Belt, Vietnam: Implication for the Silurian magmatic-metamorphic event. Journal of Asian Earth Sciences 226, 105070.
+ 01 poster presentation in the international conference: Vuong Bui Thi Sinh, Yasuhito Osanai, Nobuhiko Nakano, Ippei Kitano, Tatsuro Adachi, Tuan Anh Tran and Pham Binh, 2021. Petrology and zircon U–Pb geochronology of pelitic gneisses and granitoids from the Dai Loc Complex in the Truong Son Belt, Vietnam. GEOSEA XVI-GeoCon, Philippin.

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