Magma source feature and eruption age of volcanic rocks in the Tram Tau district, Tu Le Basin

Abstract

A set of samples including porphyritic rhyolite, rhyo-trachyte, trachyte and basalt was collected in the Tram Tau district, Tu Le Mesozoic Basin, in NW Viet Nam for analysis for major, trace, elemental and Rb-Sr and Sm-Nd isotopic compositions. The volcanic rocks are alkaline and highly enriched in trace elements including rare earth elements (REEs). However, primitive mantle and chondrite trace element normalized patterns expose strong negative anomalies for Ba, Sr, Eu and Ti, possibly reflecting fractional crystallization of plagioclase (for Sr and Eu), pyroxene, and especially amphibole (for Ba and Ti). The measured Sr ratio of 0.703 would occur, respectively, at 3÷4% and 2÷5% to generate the observed strontium isotopic ratios in the Tram Tau volcanic rocks.

Seasonal 222Rn activity in spring water close to rare earth element and uranium mines in North Vietnam

“…North Vietnam was affected by many tectonic and magmatic events that were sources of ore and natural radionuclide deposits (rare earth elements (REEs) and uranium mines) [31][32][33][34][35]. The REEs mines in North-Vietnam [36] include the Muong Hum-Lao Cai, Nam Xe-Lai Chau, Dong Pao-Lai Chau, and Yen Phu-Yen Bai REE mines, while uranium mines include Ta Xua-Son La, Dong Cuu-Phu Tho and Binh Duong-Cao Bang as presented in (Fig.…”

Obsidian and mafic volcanic glasses from the Philippines and Vietnam found in the Paris Museum Australasian tektite collection

“…In the area around sample 524's putative location (Fig. 6a), Quaternary volcanic rocks are abundant but composed exclusively of basalts (Hoang et al., 2016). Rhyolitic flows of Cretaceous age are also abundant in the Phu Yen province and named Nha Trang formation (Hennig‐Breitfeld et al., 2021).…”