Premium
Geochemistry, zircon U–PB ages and HF isotopes of the Muong Luan granitoid pluton, Northwest Vietnam and its petrogenetic significance
Author(s) -
Hieu Pham T.,
Anh g T. Q.,
Minh Pham,
Thuy Nguyen T. B.
Publication year - 2019
Publication title -
island arc
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.554
H-Index - 58
eISSN - 1440-1738
pISSN - 1038-4871
DOI - 10.1111/iar.12330
Subject(s) - pluton , zircon , geology , geochemistry , mafic , diorite , orogeny , hornblende , partial melting , petrology , magmatism , crust , tectonics , biotite , quartz , seismology , paleontology
The Indosinian Orogeny plays a significant role in tectonic background and magmatic evolution in Indochina and surrounding regions. Being a part product of the Indosinian magmatism in northwest Vietnam during late Permian–middle Triassic period, Muong Luan granitoid pluton dominantly consists of granodiorite, less diorite and granite. This pluton is located in the Song Ma suture and assigned to the Dien Bien complex. Geochemically, the Muong Luan granitoid rocks are characterized by a wide range of SiO 2 contents (59.9–75.1 wt%) and high K 2 O contents. They display typical features of I‐type granites. The presence of hornblende and no muscovite and cordierite in the rocks further supports for I‐type character of granitoids. The emplacement age of the Muong Luan pluton obtained by LA–ICP–MS U–Pb zircon is at 242–235 Ma, corresponding to Indosinian time. Zircon ε Hf values of –5.6 to –10.4, in combination with moderate Mg values of 34–45 suggested that the Muong Luan granitoid was derived from partial melting of mafic crustal source rocks, which are probably Paleoproterozoic in age as revealed by Hf model ages (T DM2 = 1624–1923 Ma).