On the whole crater cliff, the eruption texture of the east wall is the clearest. From a distance, it looks like a pyramid-shaped natural barrier, and from a close distance, it looks like an inverted huge art fan. Tens of thousands of hexagonal stone pillars rise from the ground, as if attracted by a high-strength magnetic pole, and rush to the nozzle like a bottleneck, forming a radial prism, which is extremely spectacular, and is called "chinese odyssey, the first mountain in the world". Volcanoes created paleontological fossils and gave birth to precious stones. Changle sapphire, which is well-known at home and abroad, is an important mineral brought by volcanic movement.
Beiyan Volcano Group, located on the northwest slope of Haojiagou in this town, is the only area where ancient volcanic groups are concentrated in China. This group is large-scale, complete and typical, and it is a non-renewable geological heritage. It can be clearly seen from the magnificent and changeable crater profile that the volcanic eruption texture here is particularly clear and the overall image is particularly spectacular. Some are like unstoppable rockets ready to go, some are like 10,000 swords that pierce the sky, some are like neat salutes that have been specially set off, and some are like an ancient book with silk threads arranged vertically. Especially in the middle, it shows the unique landscape of volcanic lava overflowing twice. The fan-shaped columnar joints formed by the first overflow of magma on the right side were obviously cut off by the vertical columnar joints formed by the second overflow of magma on the left side. According to experts' research, this landscape of oblique spraying first and then direct spraying, where two different lava eruptions intersect, is really a wonder of the world, and it is only here in China at present.
Changle ancient crater (group) has important scientific value for studying Cenozoic tectonic movement, magmatism and geological seismology, and is also an excellent place for tourism and geological science education. At present, the local government is relying on the advantages of ancient volcanic group resources to build an ancient volcanic group geological park integrating scientific research, tourism and treasure exploration.
Tuanshanzi crater, one of the 20 craters in Changle-Linqu volcanic basin, is a rare well-preserved crater in China. This crater is a basalt plug filled in a volcanic tube. After more than 2 million years of long-term weathering and denudation, it was stripped off the ground. The columnar joints of rock bolts develop radially, converge upward and spread downward, which vividly records the natural landscape of volcanic eruption at that time and shows the ingenuity of nature. Cylindrical joints have three sides, four sides, five sides and six sides. Affected by the cooling rate, the closer to the center of the crater, the more sides.