Petrochemical characteristics of Tak volcanic rocks, Thailand: Implication for tectonic significance

Abstract

© 2019 Science Society of Thailand under Royal Patronage. All rights reserved. Tak volcanic rocks, found in the southern part of the Chiang Khong-Lampang-Tak volcanic belt in northern Thailand, provide important evidence of the tectonic evolution of the Palaeotethys ocean. Petrographically and geochemically, the volcanic rocks selected for this study are made up of rhyolite, rhyodacite, andesite porphyry, and basalt. Based on field investigations, these rocks are also associated with other igneous rocks including granite, granodiorite, tuff, gabbro, and cumulus gabbro. The chemical data acquired from X-ray fluorescence, inductively coupled plasma atomic emission spectroscopy, and inductively coupled plasma mass spectrometry methods suggest that the studied rocks from the eruption can be separated into eight magmatic groups and four tectonic settings. The tectonic setting of the southern location of Chiang Khong-Lampang-Tak volcanic rocks consists of (1) an active continental margin (Groups V and VII), (2) a back-arc basin (Group VI), (3) post-collision (Groups II and III), and (4) continental rifting (Groups I, IV, and VIII).