超越板块构造——我国构造地质学要做些什么?

Beyond Plate Tectonics: What Do We Do in Structural Geology?

对近十年来全球构造学和构造地质学的重要进展进行了简要评述 .30年前建立的全球构造理论改变了人们对地球及其演化的认识 .作为固体地球统一理论的板块构造主要涉及刚性板块边界之间的变形、地震活动和火山作用 .至今还没有完整理论阐明板块运动的驱动力和地幔对流机制 .板块边界和板内变形等许多问题仍然无法回答 .大陆岩石圈和大洋岩石圈在成分、厚度和力学强度方面有明显的差别 ,因此现有板块构造不完全适合于大陆构造 .大陆地壳和地幔流变学的综合研究是认识大陆构造和超越板块构造的最佳途径 .流变学是大陆造山带几何学和动力学的桥梁 .大陆岩石圈对构造作用、重力作用和热作用的响应在很大程度上取决于其流变强度 .岩石圈流变性质是岩石圈分层和塑性流动的主导因素 .大量透入性变形和巨型大陆造山带内部构造显示非刚性特征 .大陆构造和力学行为主要由地壳强度而不是地幔强度所控制 .从大陆岩石圈多层性和力学强度不均匀性表征看 ,现在是抛弃传统“三明治”构造模式的时候了 .面对地球系统科学和地球动力学新思维发展趋势 ,多学科综合研究大陆构造 (造山带 )

The major progresses of the global tectonics and structural geology in the last 10 years are reviewed. The new global tectonics that emerged three decades ago profoundly changed our understanding of the earth and its evolution. Plate tectonics as a unifying theory of the earth mainly is connected with deformation, seismicity and volcanism within plate boundaries. No comprehensive theory accounts satisfactorily for the driven force of plate motion and mechanism of mantle convection. Many of the problems of plate boundary formation and inter-plate formation remain unanswered. Continental lithosphere is significantly different from oceanic lithosphere in the aspects of composition, thickness and mechanical strength. However, the plate tectonics is not applied to continental tectonics as well. Comprehensive study for rheology of continental crust and the upper mantle is the best way in understanding continental structure and beyond plate tectonics. Rheology is the liaison between geometry and dynamics of continental orogeny. Responses of continental lithosphere to structuring, gravitation and thermodynamics largely depend on its rheological strength. Rheological strength of continental lithosphere is closely connected with stratification and heterogeneity. The pervasive deformation and internal structure of wide continental orogenic belts indicate non-rigid behavior. Continental tectonics and mechanical behavior are controlled by strength that resides mainly in the crust rather than in the mantle. From the view of multi-layering and mechanical heterogeneity of continental lithosphere, it is time to abandon the sandwich model. Facing development trend of earth science system and new thinking of geodynamics, multidisciplinary study on continental structure (orogenic belts) and promptly training outstanding talent is an urgent task.