Petrochemitry and zircon U-Pb age of Granodiorite-tonalite in the A'nyemaqen ophiolitic belt and its Tectonic significance

摘要

Zircon U-Pb age determination and petrochemistry research of the granodiorite-tonalite intruded in Buqinshn ophiolitic melange, the western sector of A'nyemaqen ophiolitic belt, are first done and Reported in this paper. Its zircon U-Pb age is 402±24Ma and belongs to Late Caledonian. The rock Belongs to calci-alkaline series, has the features of island-arc granite, which hints that oceanic crust Subduction and island-arc magmatism event occurred in the area in Early Paleozoic. The research Achievement is of great significance to re-understand the tectonic framework and evolution of the area, Even the Central Orogenic Belt.