Yunnan Mine Tour (Lumachang Silver Mine in Ludian-1)

Lemachang Silver Mine is located in the direction of 250 in Ludian County, Zhaotong area, northeast Yunnan, with a horizontal distance of 23km. The northeast direction of the mining area is 35, which is consistent with the structural line. The mining area is 5.26 kilometers long, 65,438 0.27 kilometers wide and 6.70 square kilometers in area. The general survey confirmed that it is a large independent silver-rich deposit.

The highway mileage from the mining area to Longtoushan Town is about 7km, which is a simple rural highway, 40km from the mining area to Ludian County, and the third-class asphalt road from Longtoushan Town to Ludian County. The mining area is 67km from Zhaotong City, 3 10km from Kunming and 30 km from neijiang-kunming railway Zhaotong Station, with convenient transportation.

From Kunming, you can choose the passenger shuttle bus to Zhaotong, and then transfer from Zhaotong to Ludian. In order to save time, we choose to rent a car from Kunming.

Starting from Kunming at 8: 00 in the morning, stop and go all the way, the scenery is good, and there are "avenues" along the way. However, after coming out of Zhaotong, it began to rain lightly, and everyone decided to change their plans and stay in Ludian County.

At 6: 30 in the afternoon, Ludian county restaurant, two meats, three dishes, one soup and a delicious meal. After dinner, the clouds cleared and the sky was full of stars. The moon rises in the lunar calendar1July, which indicates that the next day will be a fine day.

After breakfast, I finished my own business and dawdled until eight in the morning. The weather was fine, and we walked slowly along the third-class asphalt road. Autumn is blooming on the hillside. Let's walk and shoot all the way.

After more than an hour, we came to Longtoushan Town.

Longtoushan Town was called Zhudingshan in ancient times, and Ma Le Factory in Babao Village in China was a prosperous place for silver production in history. As early as the Han Dynasty, this is the main producing area of Zhu Ti Silver, which is famous all over the world. The town government is located about 3 1 km away from the county seat, bordering Huodehong Town, Dashuijing Ancient Buildings Ancient Architecture Township and Wenping Town in the east, Baogu Town in Qiaojia County across the Niulan River in the south, Lehong Town in the west and Xiaozhai Town and Shuimo Town in the north.

Longtoushan Town is the only way from Lehong Township to the county seat. The highest altitude is 2860 meters, and the lowest altitude is 90 meters, representing the altitude of 1542 meters. It is a typical dry-hot valley with an annual average temperature of 14.9 degrees, a frost-free period of more than 290 days and an annual rainfall of 700- 1 100mm, which is under the jurisdiction of the whole town.

Longtoushan Town is rich in hydropower resources. There are Longquan River and Shaba River in the town, and there are one, two, three and four power stations, Longqiao Power Station, Hongshiyan Power Station and the ceiling power station that will be put into production soon. It mainly produces cash crops such as flue-cured tobacco, pepper, walnut, pepper, peanut, garlic and vegetables. Pepper, walnut and garlic are the characteristic cash crops in Longtou Mountain.

Longtoushan Town has a long history and profound cultural heritage. Longtoushan, called Zhudingshan in ancient times, is the birthplace of Zhudingshan culture. From the fifth year of Qing Qianlong to the fifth year of Jiaqing, the operation of silver and copper mines in Ma Le Factory was in its heyday. At that time, there were more than 100,000 miners in all provinces of China, and businessmen from all over the country joined forces to form hometown associations. Wang Yu Temple, Kannonji Temple, Architectural Temple, Black Temple, God of Wealth Temple, Wang Xi Temple, Wanshou Palace, Chusheng Palace and Shoufu Temple have their own characteristics. There are "Three-step Two-hole Bridge", "Three-step Moon Watching", Crescent Terrace, Mount Tai, Ertai Mountain, Wutai Mountain, Lee Tae and Wangxiangtai. Together with the Qi Jun charm of the Great Foshan, Laojun Mountain and Zhaobi Mountain, a magnificent and prosperous landscape is formed with pavilions, stone steps, bells and drums ringing, and peaks towering. Two osmanthus trees planted in the heyday of the silver mine have now become Lemagugui, which is 8 meters high, surrounded by three trunks and mushroom-shaped branches and leaves, covering a total area of about 50 square meters. Every June and August, the ancient osmanthus flowers are in full bloom, and the faint fragrance floats for miles with the wind. In front of the tree hangs the signboard of the key protected cultural relics unit of Ludian county government, which reads "Lemachang Ancient Silver Mine Site". Today, there are more than ten ethnic minorities living here, such as Yi, Miao, Zhuang and Hui, with convenient transportation, stable society, rapid economic development and people living and working in peace and contentment.

Further on, we began to walk on the marble road in the country, but we lost our way. Starting from Longtoushan Town, the signpost of "Lemachang Ancient Silver Mine Site" disappeared. At the fork in the road, we had to stop and ask the local villagers to guide us up the mountain. When I arrived at Babao Village, the site of the ancient silver mine in Lemachang, I asked the local children, "Where is the silver mine?" "The children showed us a way up the mountain. On the winding mountain road, I found a factory-like gate, but it was where a modern mining company was located, but the gate was closed. There was a long wait at the door, and there was silence inside. Ask the villagers why they are so empty. A: Because the mountain has been basically hollowed out, it has been stopped for safety reasons.

We can only open the geological data, find the route direction from the geological map, and plan to cross Guanyinshan mining area → Huangtuoshan mining area → Laojunshan mining area from Yaowanshu mining area, and then return to Longtoushan Town.

Learn about the geological background of Lemachang silver mining area first.

The mining area is located in the northeast Yunnan platform fold of Yunnan Dongtai fold belt on the western edge of Yangtze platform, and in the middle of the second NE-trending Lemachang fault zone east of Xiaojiang fault. The structural pattern of northeast Yunnan is a wide and gentle NE syncline and a narrow anticline.

The ore body is located in the core of Longtoushan anticline, adjacent to Xiaosai syncline in the east and Dafoshan syncline in the west. The Lemachang silver deposit is located in the thrust nappe fault zone at the core of Longtoushan anticline, and in the Lemachang silver field in the Qiaojia-Yiliang metallogenic sub-zone in the west of Zhaotong-Liupanshui silver-lead-zinc metallogenic belt, which is the late stage of Paleozoic continental rift development (the main sedimentary period). The sedimentary environment is conducive to the enrichment of silver, lead and zinc, and the abundance of this element in the stratum is high.

The above favorable tectonic environment and regional metallogenic background have created unique advantages for the formation of Lemachang silver deposit.

/kloc-arrive at Yaowanshu mine section around 0: 30, and walk up the mountain road. On both sides of the road are continuous hillsides and sporadic houses. All the way halfway up the mountain, at a corner, I searched back and forth several times and finally found the dividing line of CAMBRIAN sandstone and mudstone.

The road rises slowly along the hillside, and it is very hot. After more than half an hour, I gradually got used to the rhythm and didn't feel tired. The exposed strata in this section include upper Sinian Dengying Formation dolomite, Cambrian sandstone, mudstone and dolomite, lower and middle Ordovician sandstone mixed with dolomite, middle Devonian Qujing Formation dolomite, lower Permian bauxite and limestone. The total exposed thickness of Silurian, upper Ordovician, upper and lower Devonian and Carboniferous strata is 1500m.

After about one and a half hours' walk, we arrived at Guanyinshan ore section, saw Longtoushan anticline structure, and observed F 1 and F5 and F6 faults.

Seen from the whole mine, this structure is an imbricate thrust nappe structure distributed in the northeast direction, and the main faults cut and overlap each other to form an imbricate structure. The footwall of the nappe fault is Middle Devonian and Lower Permian, with a anticline (Longtoushan anticline) and secondary folds (Dahushan syncline and Handle Cliff anticline). The upper wall strata are Cambrian, Middle and Lower Ordovician, Middle Devonian and Lower Permian from northeast to southwest, and folds are developed in nappes.

F 1 fault: it is distributed in the south of the mining area, with a length of 1800m and a width of100 ~ 500 m. The upper strata are the Lower Permian of Middle Ordovician, which constitutes the nearly north-south Laojunshan syncline, and the lower strata are the Lower Permian, which constitutes the Dahushan syncline. Fault attitude: 80- 120 ∠ 40-70 on the west, 270-320 ∠ 20-30 on the east, and 30-45 ∠ 20-30 on the axis, forming a semi-boat-shaped fault inclined to the northeast. The rocks in the fault zone are banded, with fault mylonite at the top and bottom, breccia at the bottom and cataclastic rocks at the middle and upper parts.

F6 fault: distributed in the middle and north of the mining area, extending 4500m, with extrusion width100 ~ 800m. The upper wall is composed of clastic rocks and dolomite of Saiwu system, and the lower wall is composed of limestone and dolomite from Middle Devonian to Lower Permian. The fault occurrence is similar to F 1, and the gravel consists of sand, mudstone, dolomite and limestone. The occurrences of F 1 fault and F6 fault are semi-boat-shaped with steep west and gentle east and opposite dip.

F5 fault: it runs through the north and south of the mining area, with a length of 5260m, and its occurrence is a high-angle thrust fault. The west side of F6 fault is cut, and early secondary west-dipping normal faults F2 and F 1 1 are developed in the upper wall of F5 and F6 respectively.

The main ore-bearing faults are F 1 and F6, and the secondary ore-bearing faults are F5, F2 and F 1 1.

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