Zircons from the S«ng Re Complex (KT.318) have the SHRIMP U-Pb analyses clustered at 436± 10 Ma with two inherited cores of 860 and 2540 Ma. The value of 436± 10 Ma dates protolith age for orthogneisses of the Song Re complex. The inherited cores are interpreted to be a relict of crustal component in the magma body. The 2540 Ma age of inherited zircon in this study is the first documented evidence for the existence of a crustal component older than 2500 Ma in this region.