Two ophiolite belts in the East Kunlun Orogenic Belt record evolution from the Proto-Tethys to Paleo-Tethys Oceans

As relics of oceanic lithosphere, ophiolites exposed in the East Kunlun region are crucial for deciphering evolution from Proto-Tethys to Paleo-Tethys. Two ophiolite belts have been recognized Orogenic Belt: northern Heishan-Dagele-Qingshuiquan Ophiolite Belt and southern Muzitag-A’nyemaqen Belt. Most basaltic rocks belt show apparent geochemical features enriched mid-ocean ridge basalts, with some suprasubduction zone-type affinity, probably formed arc back-arc settings ages 537–406 Ma. Cumulates (wehrlites) arc-related volcanics these complexes also display a subduction-related signature. However, most basalts exhibit characteristics plume-related which unrelated subduction zone. The anhydrous troctolite outcrops support this viewpoint. Statistics all available age data indicate two cycles seafloor spreading or plume activity, gave rise main epochs magmatic activity at 535–450 Ma 345–308 Ma, respectively. recorded Ocean least Early Cambrian Late Silurian. Based on geochronological comparisons, shows similarities Longmucuo-Shuanghu suture Qiangtang south, record closure opening Paleo-Tethys Ocean. spatial temporal distribution reveals long-lived system.