板块构造学说是20世纪地球科学界最大的成就之一,有关地壳的演化及大部分地质现象的成因,都可以通过板块构造学说来阐述。根据板块构造学说,地球最上层约70至100千米厚的范围为岩石圈,它由刚硬的岩石构成,我们所指的板块其实就是岩石圈。在岩石圈下面平均厚约200千米的范围,则是由粘性极大并且会流动的物质所组成,这就是软流圈。通过软流圈,我们大致可以想象到,在地球的表面,那些相互运动的刚性板 Plate tectonics theory is one of the greatest achievements of the earth science community in the 20th century. The evolution of the crust and the genesis of most of the geological phenomena can be explained by plate tectonics. According to plate tectonics, the top of the earth is about 70 to 100 km thick in the lithosphere, which is composed of rigid rocks, and the plate we are referring to is actually a lithosphere. The average thickness of about 200 km below the lithosphere is composed of a very viscous and flowing material. This is the asthenosphere. Through the asthenosphere, we can generally imagine that on the surface of the earth, the rigid plates that move mutually