Mid-Neoproterozoic Tadong amphibolites at the junction of the East Kunlun and Western Qinling Orogens – a record of continental rifting during the break-up of Rodinia

Mid-Neoproterozoic rift-related Tadong amphibolites (TDA) are situated in the junction of the East Kunlun Orogen (EKO) and the West Qinling Orogen (WQO) in western China, and have important significance in the break-up of the Supercontinent Rodinia. The mineral assemblage of the TDA exhibits amphibolite facies metamorphism, and the protolith is basic volcanic rocks. Here, we present a detailed laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) zircon U–Pb age and geochemical data of TDA. LA-ICP-MS U–Pb zircon age determination indicates that the basic volcanics formed at ca. 743–711 Ma. Geochemically, TDAs are characterized by low SiO2 (46.06–50.18%), K2O (0.66–1.86%), and Mg# (40–45) and high TiO2 (1.9–3.5%), and are attributed to tholeiite basalts. Their chondrite-normalized REE patterns are characterized by moderate enrichments in LREEs (LREE/HREE = 4.98–5.51) with insignificant Eu anomalies (δEu = 0.99–1.12). The primitive mantle-normalized trace element diagrams are chara...