Shanxi Formation

例句：

1. 1. The Shanxi Formation is a key part of the geological record.
   山西组是地质记录的关键部分。
2. 2.The Shanxi Formation contains fossils that are over 500 million years old.
   山西组包含的化石距今超过5亿年。
3. 3. The Shanxi Formation was formed during the Late Cretaceous period.
   山西组是在白垩纪晚期形成的。