地壳在其整个发展过程中,曾经经历过几次由海洋转变为大陆以及继之以大洋化的漫长的周期。最后一次转化周期包括古生代、中生代和新生代,即包括大致6亿年的一段时间。在这个时期内,地壳曾经历了五次大的地槽和造山运动阶段:贝加尔、加里东、海面、中生代和阿尔卑斯。由于这些褶皱作用的结果,一些古陆核被越来越年轻的褶皱构造所包围。但是,某些大陆(例如:非洲、南美洲和澳洲)却被分割。这些褶皱运动的最后一次——阿尔卑斯 During its entire development, the crust has experienced a long period of several cycles from the ocean to the mainland and the subsequent oceanification. The last conversion cycle includes the Paleozoic, Mesozoic and Cenozoic, which includes a period of roughly 600 million years. During this period, the Earth’s crust experienced five major stages of the Trough and orogeny: Baikal, Caledonian, Sea, Mesozoic and Alpine. As a result of these folds, some ancient land cores are surrounded by younger and younger fold structures. However, some continents (eg Africa, South America and Australia) are divided. The last of these fold movements - the Alps