geologic time

例句：

1. 1.The study of geology is essential forunderstanding the history of our planet.
   研究地质学对于理解我们星球的历史至关重要。
2. 2. Theage of the Earth's crust isdetermined by its geologic time.
   地球地壳的年龄由其地质时代决定。
3. 3. Theformation of rocks and minerals in the earth's crust is a result of geologic processes.
   地球地壳中岩石和矿物的形成是地质过程的结果。