<em>c</em>. 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

Abstract

<p>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 <em>P–T</em> 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 <em>c</em>. 1.85 Ga assembly of the Columbia supercontinent. Similar <em>c</em>. 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. </p