Gushan Formation

例句：

1. 1. The Gushan Formation is a series of sedimentary rocks that were formed over millions of years.
   古山系是一系列数百万年形成的沉积岩。
2. 2. The Gushan Formation is known for its unique rock formations and geological features.
   古山系以其独特的岩石结构和地质特征而闻名。
3. 3. The Gushan Formation is an important source of minerals and resources for the local economy.
   古山系是当地经济的重要矿物和资源来源。