In ancient times, people said a lot about the causes of Jinan spring water. Some people think that Jinan spring water comes from Wu Wang, Henan. For example, Shen Kuo in Song Dynasty said in "Talk about Meng Xi" that water flowed eastward from the king of Wu, sometimes hidden underground, and springs gushed out from Jinan underground. In the Ming Dynasty, Hu Youshi said: "Wang Zhai flows in the mountain spring, and Bo Qing thinks about it." The predecessors also had correct views on the source of Jinan spring water. For example, Ceng Gong in the Song Dynasty and Yuan Haowen in the Jin Dynasty thought that the spring water in Jinan did not come from the water, but from the mountainous area south of Jinan. In order to find out the source of spring water, Ceng Gong once went into the mountains to investigate and thought that the underwater seepage in the southern mountainous area penetrated into the urban area and emerged as spring water. He said in "Two Chapters of qi zhou": "The water in the valley in the north of Mount Tai and the southeast of Qi meets at the Black Water Bay (i.e. Jinyang River) in the northwest, at Baya Bay in the northwest (suspected in Baya Mountain), and as for the thirsty horse cliff (now something in Dangjiazhuang). There is a lot of covered water, turning north and west, especially sick. As for the cliff, stop there. From the north of Cliff to the west of Licheng, five miles from Fiona Fang, there is a spring gushing out, or several feet high, and the name next to it is Chutu Spring. ..... Gaiquan has been thirsty for Ma Cliff and has returned. " According to the investigation and study of modern geologists, Jinan spring water comes from the southern mountainous area of the city. Atmospheric precipitation seeps into the ground and flows northward along the inclined direction of rock strata, which is blocked by the intrusive rock mass in the city, and the confined water emerges from the surface to form spring water.
The southern mountainous area of Jinan is the remnant vein of Mount Tai, with Zhongshan, low mountains and hills from south to north. The urban area has become the combination zone of the piedmont inclined plain and the Yellow River alluvial plain, with a height difference of more than 500 meters. This terrain is high in the south and low in the north, which is conducive to the collection of surface water and groundwater in the urban area. Geologically, the southern mountainous area belongs to the northern wing of Taishan uplift, which is a gentle monoclinal structure. Many fault blocks have been formed by the cutting of faults on the north side, among which Qianfo Mountain fault block is the structural basis of urban spring groups. Pre-Sinian metamorphic rocks are the basement of mountainous areas, on which there are 1000 meters thick CAMBRIAN and Ordovician limestone. The rock stratum inclines to the north with an inclination of 3 ~ 15 degrees until it is buried under the Quaternary sediments in the urban area. In the long geological age, these soluble limestones have developed karst landforms after many tectonic movements and long-term dissolution, and formed a large number of karst gullies, caves, underground rivers and so on. Together, they form a vein-like underground network, which can store and transport groundwater. The northern part of the city is Yanshanian gabbro body with fine texture, hard rock and good waterproof performance. There is a Qianfoshan fault passing through Wei Yi Road in the west of Qianfoshan fault block; Yangtouyu fault in the east passes through jiefang bridge and Laodongmen, forming water-blocking rock mass in the east, west and north, forming a drainage unit with three sides closed. In the southern mountainous area, limestone is exposed and fractured karst is developed, which absorbs a large amount of atmospheric precipitation and surface runoff and penetrates into the ground to form rich fractured karst water. These fissured karst waters, blocked by Archean metamorphic rocks, move horizontally to the north along the inclined direction of rock strata, forming an underground undercurrent. When the urban area is blocked by intrusive rocks and blocked by faults, underground undercurrents gather in large quantities, changing from horizontal movement to vertical upward movement, which promotes karst development and water level rise. Under the strong hydrostatic pressure, groundwater passes through karst fractures, grabs the ground in the contact zone between limestone and intrusive rocks and weak Quaternary sediments, and gushes out of the ground.