Whether or not the Altyn Tagh terranes in northwest China were part of the Rodinia supercontinent is unclear due to the apparent absence of rift-related igneous rocks. We present U-Pb geochronology, mineral chemistry, whole-rock major and trace element and Sr-Nd isotope data for the Yapuqiasayi mafic dykes in the North Altyn Tagh. Zircon and baddeleyite from a mafic dyke sample yield indistinguishable U-Pb results and a weighted mean 207Pb/206Pb date of 740 ± 11 Ma,...