Age of the Shahewan rapakivi granite in the Qinling Orogen, China, and its constraints on the end time of the main orogenic Stage of this orogen

摘要

the Qinling Mountains in central China are a joint orogenic zone between the Sino- Korean(or North China)and the Yangtze(or South China)craton blocks, the two major tec- Tonic units of eastern Asia. On the time of the main orogenic stage in this orogenic belt There are different opinions. The ~40Ar/~39Ar Rb-Sr and zircon U-Pb ages of a recently discovered Rapakivi granite in the Qinling Orogenic Belt are reported and the end time of the main orogenic Stage for subduction-colliction-collision in their belt is discussed.