Abstract:

Abstract:  The North Dabie dome resulted from the postorogenic extension in Early Cretaceous. The NWWstriking, NNEdipping XiaotianMozitan shear zone in the northern boundary of the dome is a normal sinistral, ductile shear zone whereas the NWstriking, SEdipping WuheShuihou shear zone in the southern boundary is a dextral reverse, ductile shear zone. Field structural investigation, analyses of quartz Caxis fabric, kinematics and deformation temperatures as well as deformation modeling for the two shear zones demonstrate that they originated from the same subhorizontal, midcrustlevel ductile shear zone with shear sense of toptoNWW(280°) and dominance of simple shear deformation. Thereafter, this subhorizontal shear zone outcropped at the boundaries of the dome due to exhumation related to doming of the North Dabie associated with massive magmatism in the Early Cretaceous. Deformation modeling indicates that the present North Dabie dome occurs as an antiform with an EW trending axis, and the western segment of the dome experienced more intensely doming than the eastern. It can be concluded from the development that the socalled North Dabie dome belongs to typical metamorphic core complex in the Dabie orogenic belt.

Key words: Key words: North Dabie dome; detachment shear zone; deformation modeling; XiaotianMozitan shear zone; WuheShuihou shear zone