Timing of Precambrian basement from east segment of Tiekelike tectonic belt, Southwestern Tarim, China: Constrains from zircon U-Pb and Hf isotopic

This study focuses on the determination of the age and provenance of a Precambrian unit on the southwestern margin of the Tarim craton, collectively known as the Ailiankate (埃连卡特) Group and Sailajiazitage (塞拉加兹塔格) Group, which were previously referred to as Paleoproterozoic-Mesoproterozoic. Zircon U-Pb LA-ICP-MS dating of chlorite quartz schist and tuff that form the Ailiankate Group and Sailajiazitage Group have yielded age peaks at 780 and 787 Ma, respectively. These data indicate that the Ailiankate and Sailajiazitage groups are Neoproterozoic succession deposited at ca. 740–790 Ma. Those strata are temporally equivalent and are likely parts of a single wide spread succession and reflect a rifting process related to the break-up of the Rodinia supercontinent. In situ zircon Hf isotopic data from Sailajiazitage Group show that older zircons (∼1 994 Ma) have crustal model ages of 2 272–2 784 Ma, suggesting an ancient crustal growth and reworking. The ∼787 Ma zircons have ∼2 000 Ma crustal model ages, suggesting derivations from recycled Paleoproterozoic material.