The Metamorphic and Deformational History of a Continental Collision Zone and its Geodynamic Process——as Evidenced by Qinling Complex,Western Henan,China

摘要

The Qinling orogenic belt is a collision zone between the North China andYangtze cratons.The Qinling Complex is a Precambrian metamorphic com-plex,developed in the inner zone of the orogenic belt,which records themetamorphic and deformational history and PTt path of the regional meta-morphism of the collision zone.The present paper studies the metamor-phic and deformational history and the PTt path of various tectono-metamorphic cycles in order to describe the geodynamic processes prevailing inthat part of the Qinling orogenic belt since Proterozoic.The tectonometamorphic history and evolution of the Qinling Complex isdivided into two stages:the stage of formation and the stage of modificationDuring the stage of formation dated as Proterozoic,three deformational se-quences are recognized.The amphibolite facies regional metamorphism is earlierthan or synchronous with the first or second phase of folding.Threemetamorphic zones,i.e.And-Ms,Sil-Ms,Sil-Kfs are delimited.During thestage of modification,the