654.38+0.8 million years ago, due to the reactivation of Yishu regional fault, basaltic magma in the deep crust rushed out of the crust along the weak zone of the crust, forming a large-scale volcanic eruption in Weifang today, and the volcanic activity in this area gradually stopped until Neogene Pliocene. In 1000 million years, * * there were three large-scale volcanic eruptions, covering an area of more than 1000 square kilometers. Volcanic activities have brought us many valuable mineral resources. Sapphire is an important mineral brought by volcanic activities, and it is also a high-quality mineral water containing many trace elements.