【摘要】 就大别山及邻区若干重要基础地质问题作了较深入阐述,并据前人资料与新近调查成果,进一步明确:(1)北淮阳地区属扬子地块北缘,与华北地块南缘的分界为固始—肥中断裂以北。(2)超高压变质带内新元古代浅变质岩层确系存在,并与榴辉岩及其他超高压岩石,共同经受两期褶皱变形,形成早期为伸展拆离,主期为收缩挤压叠加褶皱变形带,而非外来构造残片,或俯冲过程被铲刮下来的"构造加积楔"。(3)蓝片岩形成于伸展拆离构造带内。榴辉岩为地幔岩,属岩浆成因。其他超高压岩石与"柯石英"可在"地壳异常压力"与"高压釜"机制联合作用下,在地壳较浅层次的伸展拆离构造环境下形成。(4)广泛分布的新元古代火山岩系及侵入岩,代表了晋宁期地壳被强烈拉伸-裂解-扩张事件,但未形成洋壳盆地。(5)详细描述了大别山及邻区构造变形及拉伸与生长线理特征以及形成机制,认为是由"地幔差速环流"所引发的岩石圈与地壳各分层间伸展拆离-滑断剪切过程中形成。大别造山带经历了裂解成盆、伸展拆离、收缩挤压、热隆成山,由多阶段构造运动所完成,而非板块碰撞造山。更多还原

【Abstract】 Some important basic geological issues about Dabieshan and its adjacent regions have been expounded in detail in this paper,and further defined that(1)North Huaiyang region belongs to the northern margin of Yangtze Block,the boundary between it and the southern margin of the North China Landmass is the north of Gushi-Feizhong Fault Zone;that(2)Neoproterozoic low-grade metamorphic rock series certainly existed in the ultrahigh-pressure metamorphosed belt,it has undergone two phases of fold deformation with the eclogite and other ultrahigh-pressure rocks,forming a deformed belt which was extensional detachment in the early stage,and contractive compression in the major stage,which are not the foreign tectonic remnants or tectonic accretionary wedge caused by the subduction process;that(3)the Blue Schist was formed during the extensional detachment,eclogites are pyrolite and magmatic origin,and other ultrahigh-pressure rocks and"coesite"could be formed by the joint action of the "Earth’s crust abnormal pressure "and "high-pressure autoclave",in the extensional detachment environment within the entire shallow crust;that(4)widespread Neoproterozoic volcanic and intrusive rocks represent the intense tension-cracking-expansion event occurred during the Jinningian,but no ocean-crust type basin formed;that 5.the characteristics and forming mechanism of the stretching and growth lineation in Dabieshan and its adjacent regions have been described in detail,and this paper suggests that it was formed in extensional detachment-slip shear process within the lithosphere and different layers of crust caused by "mantle differential circulation".The Dabie Orogen Belt has undergone multi-stage tectonic movements,including cracking into a basin,extensional detachment,compressive squeezing and thermal uplift to form mountains,which was not formed by plate-collision orogenesis.更多还原