Reasons for the formation of the three major tourist sites in ancient China and geographical topics

Three Gorges. There are different opinions about the concrete formation of the Three Gorges, and the more consistent view in the field of geography and geology is that a series of folded mountains such as Wushan were formed in eastern Sichuan and western Hubei during the Yanshan Movement 7 million years ago. They change from southwest-northeast to east-west, and the terrain gradually decreases from south to north. Between these mountains and Bashan Mountain in the north is a relatively low-lying area, and the Xiajiang section of the ancient Yangtze River flows eastward along this low-lying area. As the crust in this area continues to rise, the river cuts more and more violently, and finally the Three Gorges is formed.

Guilin. Because the surface water flow is concentrated in the rocky mountain, it makes the rocky mountain stand steeply around. Form a lonely peak that rises from the ground. Sometimes the cliff is thousands of feet high and majestic, forming a "stone mountain"; When there is a hole in every mountain, the rapids that hit the top of the cave can be eroded and dissolved into a "stone pot" in the flood season, and the groundwater penetrates along the joints and is dissolved at the dripping place of the cave top to form a "stone clock"; The rise of the earth's crust or the decline of the groundwater level leads to the rise of the foot hole and the formation of "hole-piercing".

east Zhejiang. During the Mesozoic era, during the subduction of the Pacific plate (called paleo-Pacific) to the Asian continental plate, the compression friction generated heat energy, which partially melted the upper crust and the lower crust to form magma. When there is a fault leading to the surface, the magma rises to the surface along this passage, and the volcano erupts. After experiencing the process of volcanic eruption, collapse, resurrection and uplift, magma covered the original landform, forming the hills of eastern Zhejiang, which are composed of solitary boats, hemp fiber, fishermen, dusk, shoals and sandbars.