The process of vertical movement, known as isostasy, was a foundation of geological beliefs for generations, though no one had any good theories as to how or why it happened.

垂直移动的过程，即所谓的地壳均衡，几代人地质念的一个基础，虽然谁也提不出令人服的理论来解怎么发生的，或为什么发生。