论文部分内容阅读
北大别穹隆是在早白垩世造山后伸展活动中形成的。其北界为北西西走向、倾向北北东、正左行平移的晓天—磨子潭韧性剪切带,南界为北西走向、倾向南东、右行“逆冲”的五河—水吼韧性剪切带。通过对这两条剪切带的构造观测、运动学分析、石英C轴组构测量、变形温度分析及变形模拟,表明剪切带原先为中地壳同一近水平的韧性拆离剪切带。该拆离剪切带在原始近水平状态时的活动为上盘向280°方位的伸展运动。随后在大规模岩浆活动与北大别穹隆的隆升中,这一剪切带被动地抬升与剥露,而出露于现今的穹隆边界上。变形模拟显示,北大别穹隆构造现今为近EW轴向的背形,其上隆幅度西强东弱。北大别穹隆的形成过程表明为典型的造山带变质核杂岩。
The North Dabie Dome was formed during the Early Cretaceous orogeny. The north boundary is northwest-westward, north-easterly eastward, right-lateral translation Xiaotian-Mozi Tan ductile shear zone, and the southern boundary is northwestward, with a tendency of southeastern, rightward and “thrusting” - Water roar ductile shear zone. The structural observation, kinematic analysis, quartz C-axis structure measurement, deformation temperature analysis and deformation simulation of the two shear zones show that the shear zone was originally the same near-horizontal ductile detachment zone in the middle crust. The detachment shear band in the original near-horizontal state of activity for the upper disc to 280 ° orientation of the stretching movement. Subsequently, during the large-scale magmatic activity and the uplifting of the North Düssenstein dome, this shear zone was passively lifted and exhumed, revealing the present vault boundary. Deformation simulation shows that the structure of the North Dabie Fossa is now nearly EW axial dorsal form, and its uplift amplitude is stronger in the west and weaker in the east. The formation of the North Dabie Fold indicates a typical orogenic metamorphic core complex.