摘要:
块体理论起源于大陆,通过与大洋板块学说从空间域、时间域、基本构造单元、驱动力等方面的对比分析认为,该理论也可以延伸并推广到全球范围,使得以大陆地壳为主要研究对象的块体学说,与以大洋地壳为主要研究对象的大洋板块学说遥相呼应并互为补充,使得全球构造理论体系趋于完善。块体理论对中国海陆构造格架演化的有效应用是勾画出了"块体构造理论"的最基本框架体系。由此得出块体的主要地学特征:首先是在块体内需要一个可以成为内核的生长中心(一般是年代古老的块体核心——元古代甚至是太古代),其后是在古老内核周边出现岩浆活动以及活化的造山带,两者逐渐依附于或是粘贴在块体核心部位的外围,使块体在后来的演化过程中体量不断增长,直到出现新的崩裂(形成新的块体)或是与其他块体一起汇聚于未来的超级大陆。其次是明确了块体的边界有3种基本类型:对区域构造有控制作用的深大断裂、主动型大陆边缘和被动型大陆边缘。块体的一般地质构造演化阶段也可以分为胚胎期、幼年时期、成长发育时期、衰亡期4个主要阶段,这4个阶段构成了块体地质演化的一个完整的生命周期。
Abstract:
The theory takes the continental crust as its main research theme, and the oceanic crust remains the main research interest of the oceanic plate tectonics. The two theories complement each other, and become a perfect theoretical system of global tectonics. Every block requires a nucleus (usually Proterozoic or even older) as the core of growth. Around the old nucleus, there are magmatic activities and orogenic belts making the block growing larger until the emergence of a new split to make new blocks. With time, the new blocks may merge together with other blocks to become a supercontinent. There are three basic types of block boundaries, i. e. deep and large faults, which control regional tectonics, the active continental margin and the passive continental margin. The geotectonic evolution of a block can be divided into the embryonic stage, the infancy stage, the growing and expanding stage, and the decline stage. The four stages make up a complete life cycle for the geological evolution of a block.
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