stratigraphical time table

例句：

1. 1.The geologist studied the rocks in the area to determine their stratigraphical order.
   这位地质学家研究了该地区的岩石，以确定它们的地层顺序。
2. 2.The fossils found in the stratigraphical layer are evidence of ancient life.
   在地层中发现的化石是古代生命的证据。
3. 3.The stratigraphical sequence is crucial for understanding the history of the region.
   地层序列对于理解该地区的历史至关重要。