【摘要】 通过对内蒙古大青山—乌拉山地区高级变质杂岩的研究发现,区内孔兹岩系先后遭受到近水平顺层滑脱变形、穹-褶构造和近东西向陡倾叶理带的改造。由于近水平顺层滑脱变形,这些变质地层发生“岩层缺失、隔层相触”,在空间上表现为近水平的长轴近东西向的扁豆体堆叠而成的变质地层结构,而后期近东西向陡倾叶理带的叠加,又使得这些变质地层在空间上以不规则条带状、不规则团块状或透镜状形式出露,各变质地层单位之间及与其他变质岩系之间显现出“犬牙交错、参差产出”的特征,从而显示出十分复杂的变质地层结构。可以确定,区内孔兹岩系至少经历了2个造山旋回,近水平顺层滑脱变形构造及对应的变质地层结构是早期造山旋回后期阶段的产物,而近东西向陡倾叶理带及相应的变质地层结构则属于后期造山旋回。更多还原

【Abstract】 Study of the high-grade metamorphic complex in the Daqingshan-Wulashan area,Inner Mongolia,indicates that the khondalite series in the area has undergone subhorizontal bedding-parallel dêcollement deformation and then modification by the dome-fold structure and nearly E-W-trending steeply dipping foliation belts.The former resulted in "omission of strata and hiatal contact of originally separated layers,which in space is indicated by the structure of metamorphic strata formed in the early stage by stacking of subhorizontal podiform bodies with nearly E-W-trending long axes.The stacking of the nearly E-W-trending steeply dipping foliation belts in the late stage caused the metamorphic strata to occur as irregular bands,patches or lenses and various metamorphic units and series to occur in a jigsaw-like form and interlock each other.It is concluded that the khondalite series underwent at least two orogenic cycles.The subhorizontal bedding-parallel dêcollement deformation structure and its corresponding structure of metamorphic strata are the product of the late stage of the first orogenic cycle,while the nearly E-W-trending steeply dipping foliation belts and their corresponding structure of metamorphic strata are attributed to the second orogenic cycle.更多还原