c . 1.85 Ga HP granulite-facies metamorphism in the Dunhuang block of the Tarim Craton, NW China: evidence from U–Pb zircon dating of mafic granulites

Mafic granulites of the Dunhuang block, eastern Tarim Craton, record high-pressure granulite-facies metamorphism followed by a medium- to low-pressure granulite-facies metamorphic overprint, suggesting a clockwise P–T path and implying an environment of collisional orogenesis. Zircon U–Pb ages of two samples are 1834 ± 12 Ma and 1842 ± 5 Ma. Mineral inclusions in zircon indicate that these ages record the high-pressure granulite-facies event, suggesting that the Tarim Craton may be related to the c . 1.85 Ga assembly of the Columbia supercontinent. Similar c . 1.85 Ga metamorphism in both the Dunhuang block and the Alxa block of the North China Craton supports their correlation across the Altyn Tagh fault. Supplementary material: Analytical procedures, mineral abbreviations, mineral chemistry and U–Pb dating data are available at www.geolsoc.org.uk/SUP18541 .