... sample(VN571) in the northern part of the studiedarea, far from zone of shear, has beeninvestigated.Age of thissamplecorrespondstoage of metamorphism of Kham Duc Formationat255.9 ... tectonicevolution of the Lancang paired metamorphicbelts, south‐western China, Journal of metamorphic geology 11(1993)605.[18] Tran Quoc Hai, Precambrian stratigraphy of Indochina,in Geology of Cambodia,LaosandVietnam,Institute ... degree of metamorphism varies quickly, according toobserved sectors. To the east, immediately atthe South of Que Son massif, it exposes oneisodegree of metamorphism of ...