Geochronology and geochemistry of volcanic rocks in the Arbasay Formation, Xinjiang Province (Northwest China): implications for the tectonic evolution of the North Tianshan

A new study challenges the long-held belief about the geological age of volcanic rocks in the Arbasay Formation, Xinjiang Tianshan. Using advanced geochronology techniques, including zircon U–Pb dating via LA-ICP-MS, researchers determined that these volcanic successions formed during the late Carboniferous period (308–305 Ma), not the early Permian as previously thought. The study also revealed that the rocks exhibit calc-alkaline geochemical signatures typical of continental arcs, enriched in LREEs and LILEs while depleted in HFSEs. This finding suggests that the volcanic activity was linked to the southward subduction of the North Tianshan Oceanic lithosphere rather than an intracontinental rift setting. The research integrates field mapping, petrography, and geochemical analysis to provide a refined understanding of the tectonic evolution in this UNESCO World Heritage Site.

Wang, J., Wu, C., Li, Z., Zhu, W., Chen, Y., Li, Q., Wu, J., Deng, L., & Chen, R. (2016). Geochronology and geochemistry of volcanic rocks in the Arbasay Formation, Xinjiang Province (Northwest China): implications for the tectonic evolution of the North Tianshan. International Geology Review, 59(10), 1324–1343. https://doi.org/10.1080/00206814.2016.1185750