CENTRAL OF VIETNAM AND TECTONIC IMPLICATIONS
Nguyễn Trường Giang
Geologycal Division Radioactive and rare elements
Abstract: Many intrusive magmatic rocks were revealed around the Mesozoic Nông Sơn Basin that are classified into different complexes. The results of the TIMS U-Pb zircon dating extracted from 07 granitoid samples yielded a range of 206Pb/238U ages ranging from 416 to 241 Ma. In combination with the existing age data and regional tectonics, it is possible to divide the evolution history of magma in the study area into 3 stages: the first is from 450 Ma to 416 Ma; the second is from 303 to 256 Ma (concentration of 294-296 Ma) with typical features of I-type granite, related to subduction; and the third stage produced syn-collision, S-type and high aluminum granite with ages ranging from 252 to 241 Ma. These new age data also show the presence of Caledonia and Indosinian tecotono-thermal events in the study area.
Keywords: Nông Sơn Basin, Tectonic, multi-stage
(Xem toàn văn: Liên hệ với Tạp chí Địa Chất – Tổng Cục Địa chất và Khoáng sản Việt Nam)