Detrital zircon geochronology of Jurassic strata in the Jianggalesayi–Washixia Basin, northwestern Tibet Plateau: Implications for the uplift history of the Altyn Tagh Orogen

Jurassic terrestrial sediments of the Jianggalesayi–Washixia Basin in the northwestern Altyn Tagh Orogen record abundant information regarding the evolution and uplift of the orogen. Investigation of this orogen is critical to establishing whether the Tarim and Qaidam basins were connected during the Jurassic. In this study, we present 474 single‐grain laser‐ablation–inductively coupled plasma–mass spectrometry detrital zircon U–Pb ages obtained from five Jurassic sandstone samples collected from four sections in the basin. Detrital zircons from the Lower Jurassic strata yield age populations of 997–726 and 551–509 Ma, indicating that the zircons were derived mainly from the southern–central Central Altyn Tagh Massif. Zircon age populations from the lower Middle Jurassic strata are 1024–838, 778–643, and 543–357 Ma, which suggest that the sediments were derived predominantly from the northern Central Altyn Tagh Massif and the southern South Altyn Tagh subduction–collision complex belt (SATSB). Zircon age populations from the upper Middle Jurassic strata are 980–830, 556–424, and 277–245, suggesting that these sediments were derived from the central SATSB. Detrital zircons from the Upper Jurassic strata display age groups of 515–387 and 325–226 Ma, indicating that these sediments originated from the northern SATSB. Uplift of the Altyn Tagh Orogen was initiated during the Middle to Late Triassic as a synchronous far‐field response to the collision of the Qiangtang Block with the Eurasian Plate. By the Early Jurassic, the Qaidam Basin was no longer connected with the Tarim Basin. During the Late Jurassic to Early Cretaceous, the collision of the Lhasa Block with the southern margin of the Eurasia Plate led to further uplift of the Altyn Tagh Orogen. The Early Jurassic sediments were derived predominantly from the Central Altyn Tagh Massif. The Middle–Late Jurassic sediment mainly originated from the South Altyn Tagh subduction–collision complex belt. During the Middle to Late Triassic, the Altyn Tagh area started to uplift and mountains formed during the Early Jurassic, separating the Qaidam Basin and Tarim Basin. Several rift basins developed during the Early Jurassic then a larger depression basin developed during the Middle Jurassic. The Jianggalesayi–Washixia Basin was a depression‐type situated in a compressional tectonic setting during the Late Jurassic.