Details

Autor(en) / Beteiligte

• Ngo, Thanh Xuan
• Bui, Hau V.
• Tran, Dung M.
• Kim, Yoonsup
• Xiaochun, Li
• Tran, Hai T.
• Kwon, Sanghoon
• Jang, Yirang
• Sang, Bui V.
• Khang, Luong Q.

Titel

Ordovician continental arc magmatism in the Tam Ky‐Phuoc Son Suture Zone, Central Indochina Block, Southeast Asia

Ist Teil von

• Geological journal (Chichester, England), 2023-02, Vol.58 (2), p.825-836

Ort / Verlag

Hoboken, USA: John Wiley & Sons, Inc

Erscheinungsjahr

2023

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The Indochina Block is considered as a part of the Indian and Australian margins of Gondwana, and the Tam Ky‐Phuoc Son Suture Zone (TPSZ) lies in its central region as the boundary between the Truong Son Belt and Kon Tum Massif (KTM). However, the early Palaeozoic tectonic nature and timing of magmatism within the TPSZ are still controversial. To tackle the issue, we present herein the zircon U–Pb ages with their trace‐element compositions of five dioritic–granitic granitoids in the TPSZ. U–Pb age dating of magmatic zircons from them suggests emplacement ages of ca. 447–450 Ma. Whole‐rock geochemistry of the samples shows low TiO2 contents (0.36–1.18 wt%) and Mg# (42.04–53.07). They display enrichment in light rare earth elements ([La/Yb]N = 4.10–15.19), pronounced negative Nb, Ta and Ti anomalies relative to the chondrite‐normalized rare earth element patterns and primitive mantle‐normalized trace‐element distribution diagrams. The whole‐rock geochemical characteristics together with zircon trace‐element compositions from the same samples revealed their petrogenesis of a continental arc tectonic setting. Combining the results from this study together with available data from the TPSZ and its neighbouring units, we suggest accretionary orogenesis was responsible for generation of the Ordovician magmatic arc in the KTM, which will provide better understanding of the Early Palaeozoic evolution of the eastern Indochina Block. The arc‐related magmatism in the Kon Tum Massif and Tam Ky‐Phuoc Son Suture Zone is dominated by early‐middle Cambrian to early‐late Ordovician. These magmatisms were evaluated from island‐arc to continental arc setting, which is discussed as products of the southward subduction under the KTM during the Cambrian‐Ordovician.