单词：the Silurian
志留纪；志留系
the Silurian的用法和样例：
例句
- Ancient plant in the early Paleozoic marine mainly to the late Silurian Period, the original plants begin boarding land.古植物在古生代早期以海生藻类为主，至志留纪末期，原始植物开始登上陆地。
- The contact relationship between Silurian and Devonian is parallel unconformity.泥盆系与志留系之间为平行不整合接触。
- It is concluded that the source supply of Silurian asphalt sandstone is mainly from Middle and Lower Cambrian.通过烃源岩及构造演化史研究认为，塔中志留系沥青砂岩的油源主要为中一下寒武统。