SUMMARY

Emplacement age and tectonic significance of the Pia Oắc granite massif, Nguyên Bình district, Cao Bằng Province

Trần Mỹ Dũng, Nguyễn Tuấn Anh, Vũ Thị Hiền, Lý Quốc Sự

The Pia Oắc granite massif is located in Nguyên Bình district, Cao Bang province, which is a part of the Northeast Vietnam-Southwest China granite-related W-Sn matallogenic belt. SIMS U-Pb dating results of zircons from the granite samples show that the granite was emplaced at 93.9±3 Ma. The rocks have initial ⁸⁷Sr/⁸⁶Sr ratio of 0.748±0.027, and their eNd(t) ranges from -10.71 to -10.42. Those results suggest that the Pia Oắc granites can be grouped into the Gejiu-Dulong-Dachang granite-related W-Sn belt in Southeast China and relate to Late Mesozoic Yanshan orogeny. The Pia Oắc granite magmas were possibly derived from partial melting of Mesoproterozoic continental crust.

Người biên tập: GS.TS Trần Văn Trị.