Age, composition and tectonic implications of late Ordovician-early Silurian igneous rocks of the Loel Volcanic Belt, NW Laos

Volcanic rocks preserved in the Houay kham area, Loei Fold Belt are important components of the giant Paleo-Tethyan igneous belt. These magmatic rocks, previously mapped as Triassic-Jurassic in age, are composed of dacitic tuff, brecciated rhyolite tuff and a small number of dioritic dikes. In this study, LA-ICP-MS zircon U-Pb dating results show that brecciated rhyolite tuff, dacitic tuff, and dioritic dyke samples have ages of 419.8 ± 1.6 Ma,...