大陆和浅海是可以沧桑变换的。进一步的研究发现大陆和深水洋盆间不仅高度悬殊而且地质结构迴然不同。如大陆的地壳厚度可以达三十至七十公里,其上部被假定性地称为“花岗岩”层;而大洋地壳仅约七公里左右或更薄,一般来说,也缺少“花岗岩”层。地球的外部是一个岩石的硬壳,即岩石圈(它的 The mainland and the shallow sea can change the vicissitudes of life. Further research found that there is not only a high degree of disparity between the continent and the deep-water ocean basin but also different geological structures. For example, the thickness of the continental crust can reach thirty to seventy kilometers, the upper part of which is tentatively called the “granite” layer; while the oceanic crust is only about seven kilometers or thinner, and in general it also lacks “granite ”Floor. The outer part of the earth is a crust of rock, the lithosphere (it’s