Causes and history of salt production in Yunnan.

In ancient times, Yunnan was a sunken inland lake. With the continuous change of geological movement for millions of years, the deep layer of inland lake has been declining, which leads to the gradual sinking and accumulation of salt and other substances, and finally forms a rock salt layer buried under the surface.

Tracing back to the recorded history, from the second year of Yuanfeng in the Western Han Dynasty (BC 1 0 9) to the late Qing Dynasty, Yunnan was always one of the salt-producing provinces. The development of social economy in Yunnan is always accompanied by the development and utilization of salt. Therefore, it is very necessary to investigate the evolution and changes of Yunnan salt producing areas, and it is also an organic part of the historical study of well salt in China.

Extended data:

Yunnan is connected with Sichuan and is called Sichuan-Yunnan Well. Although the development, use and influence of well salt in Yunnan are far less than that in Sichuan, from pre-Qin to Qing Dynasty, Yunnan was indeed the only area in ancient China that produced well salt except Sichuan. The history book says: "The difference in salt production is the result of salt in Xiezhou, the salt in Ningxia scraped on the ground, the salt in Huaizhe boiled, and the salt in Sichuan and Yunnan pumped in the well.

The salt in Fujian and Guangdong is brine, the salt in Huainan is fried, the salt in Huaibei is dry, and the salt in Shandong is fried and dried. "This is the explanation of the exploration and collection of salt-making raw materials in Sichuan and Yunnan provinces. If the production method is tested again, both places will be fried into salt. Although the fuels are different, they are all processed by the heat treatment method of evaporating water by fire.

China Knowledge Network —— Evolution and Changes of Yunnan Salt Producing Areas