Ductile Thrusting-shearing Genesis of Hongzhen Granitoid, Anhui Province

摘要

As view from the petrological, mineralogical and petrochemical studies, the Hongzhen granitoid is characterized by the autichthonous-parautochthonous transformation. The source rocks are mainly felsic clastic sediments with a small amount of intermediate magmatite in the Zhangbaling Group.The granitoid is covered by mylonite and migmatite, and the three rocks share much in common with respect to their REE distribution pattems and the W-type distribution of transition elements,indicating that they all came from identical souree rocks. The granitoid belongs to collision granites or post-orogenic granitoids resulting from ductile thrusting-shearing under 550℃ and 7 × 108 Pa conditions in the foreland of the Yangtze plate during the Late Indosinian movement, and from metasomatism plus partial melting.