A newly discovered Early Paleozoic ophiolite in Dagele, Eastern Kunlun, China, and its geological significance

摘要

This study reports the discovery of an ophiolite located in the Eastern Kunlun Orogen (Dagele, Eastern Kunlun, China) that is mainly composed of isotropic and serpentinized dunite, gabbro, and eclogites. According to the geochemical results, the ophiolite unit is characterized by the depletion of Nb, Ta, and Ti and a slight enrichment in large-ion lithophile elements, which suggests that the Dagele ophiolite was formed in an island arc environment. To constrain the time of formation of the ophiolite, gabbro samples were selected for sensitive high-resolution ion microprobe U-Pb zircon dating and yielded an age of 445 +/- 4.8Ma. By integrating the regional geological and geochronological data, we propose that the Dagele ophiolite is a suprasubduction zone-type. Further studies on this and other ophiolites in the region will provide crucial constraints on the evolution of the Eastern Kunlun Orogen as well as the Proto-Tethys Ocean in central western China.