A MULTI-STAGE
INTRUSION IN MESOZOIC NÔNG SƠN BASIN,
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
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