Petrology, zircon U-Pb age and geochemical characteristics of the Lhaguo Tso ophiolitic melange in Tibet

Lhaguo Tso ophiolite is one of the most complete ophiolite combinations in the Shiquanhe-Namco-Lhari suture zone in central Tibetan Plateau, and has great significance for restoring the evolution of ocean.This paper reports petrology, zircon U-Pb chronology and geochemical characteristics of the diabases and plagiogranites to confirm the genesis and tectonic setting of Lhaguo Tso ophiolites.The zircon U-Pb dating of plagiogranite yielded an age of 167.8±1.7 Ma (n=24, MSWD=0.22), which indicates that the Lhaguo Tso ophiolite was formed in Late Jurassic.Geochemically, the gabbros and the diabases are similar to the island arc rocks and E-MORB, suggesting a continental back-arc basin environment setting.