Yunnan Mine Tour (Shang Tang Gold Mine, Guangnan County)

When I dug up this pile of scattered pieces of paper from the corner of my desk drawer, I was having a bad day, my temperament was disordered, my inner world was on the run, and I couldn't see a glimmer of light. All kinds of disappointments, all kinds of attempts to escape, actually don't know where to go, and people with poor hearts always can't find the future direction.

That's right. If it weren't for these reasons, I might drag these gold mine travel notes recorded on paper in class. These pieces of paper, which still smell like citrus leaves, can take me back to the mine that always shines like gold, and return to the mine trip. Every night, my sore legs curl up under the headlights to write a diary.

The off-road vehicle carried me to the gold mine in Shang Tang soon. I'm still confused and uneasy in the car. It was decided temporarily on April 16, and the contract partner got on the bus and left impulsively on April 19. The growth of age has not made me more homesick, but more and more impulsive.

Shang Tang Gold Mine is located in the northwest of Guangnan County, Wenshan Zhuang and Miao Autonomous Prefecture, Yunnan Province, about 72 kilometers, in the area from Bili to Saiya in Luolitang Farm. I have never been to this mine. Listening to friends say that the vegetation is very covered, the path in the bush, or that there is no road ... this kind of worry is quickly replaced by another kind of great excitement caused by excitement. However, I have a little more real anxiety in my heart, which is rare, that is, I am not competent for my work and I am getting older and older.

Climbing to the gold mine every moment will be a further experience and challenge for my aging body, which deviates from my original intention. Because I am in poor health and physical strength during this time. I don't want to overwork.

Shang Tang Farm in Guangnan County is a famous product in Wenshan Prefecture, which sells well both inside and outside the province. The farm has an area of 2,893 mu of citrus (state-owned), including 2 125 mu of citrus, 279 mu of ponkan, 489 mu of sweet orange, and the area of non-public economic citrus 1008 mu.

According to geological data, Shang Tang gold mine was discovered in 1989, and heap leaching production started in 1993. In less than 10, nearly 22,000 gold was produced, and the output increased greatly in the later period.

Shang Tang gold deposit is divided into four ore sections, of which Saiya (accounting for 87.27% of the total reserves) and Yezhuchong (accounting for 0.93% of the total reserves) are Carlin-type gold deposits, containing clastic rocks of Banna Formation (907 ~1893m thick). Both Bodanshan ore block (1 1.22% of the total reserves) and Anlongshan ore block (0.58% of the total reserves) are basalt gold deposits, accounting for 1 1.80% of the total reserves.

In the mining area, the NE Pingzhai-Zenan reverse fault (F4), NW Lori fault (F3) and NEE-Shang Tang fault (F5) meet in the south wing of the east section of the NE Shishan anticline, which are the main ore storage spaces. The faults control the vein ore, and the interlayer fracture zone controls the output of layered ore bodies. Its regional tectonic position is located in South China Fold System, Nanpanjiang-Youjiang Rift Zone, Guixi Fault Depression and the northern part of Xilin-Baise Rift, and its local tectonic position is located at the eastern end of the concealed anticline (Bili) and the periphery of the eastern end of the anticline (Saiya).

The outcrop of the mining area is from Devonian to Triassic, and the Changyao Formation and Maokou Formation of Upper Devonian, Carboniferous and Lower Permian are missing. Late Paleozoic strata are distributed in the axis of Han Dong (Longlao) anticline, and Permian and Triassic are distributed in the wings and periphery.

Middle Triassic

Mu Lan Formation: timely fine sandstone and silty mudstone.

Banna Formation: upper member, argillaceous siltstone, 380~689 meters thick; In the middle section, it is medium-thick feldspar complex sandstone, 38 1~75 1 m thick; The lower member consists of thin to medium-thick layers of timely feldspar complex sandstone, argillaceous siltstone and silty mudstone, with a thickness of146 ~ 453 m.

Lower Triassic

Longwen Formation: calcareous mudstone, siltstone and marl.

Luolou Formation: calcareous mudstone and argillaceous siltstone.

~ ~ false integration ~ ~

Upper Permian

Changxing Formation and Suo Na Formation: silty mudstone, argillaceous siltstone and layered tuff.

Emeishan basalt stratum: basalt and tuff.

Lower Devonian

Pojiao Formation: grayish green and dark gray shale, calcareous mudstone, silty mudstone and fine ~ silty sandstone. Pyrite containing authigenic and semi-authigenic crystals. It made a top top for Tokyo wild vegetables and so on. , exposing the thickness of 20m. This stratum contains antimony and gold.

Walking all the way from the church, we arrived in Bi Li at 1: 30 in the afternoon and got a panoramic view of various geological conditions. I also walked for a long time to have lunch in a village in Niburg. Going uphill and downhill, I feel that the path in the bushes is very narrow, and it is ok in general. It's just that there were too many thorns on the branches, and I accidentally cut my hand. When going downhill, the stone shook under my feet. At that time, the stone rolled down and fell heavily to the ground without control. The left sleeve of the coat was completely torn and the left upper arm was scratched in a large area. The left knee is bleeding, the left back is bleeding, and the soft tissue outside the right thigh is badly bruised and swollen as big as an egg. Simply using Yunnan Baiyao aerosol spray, this place is the most painful, which will definitely seriously affect the follow-up walking. It's only halfway up the mountain, and there is still a long way to go. How can I get there? My companion called and asked someone to pick me up.

Finally, I saw the gold ore body of Isaiah.

Let's take a closer look at the characteristics of gold mines. Gold deposits mainly have the following three outburst points.

① The gold-bearing horizon, gold-bearing background value and Jin Yanshi have the following characteristics:

There are gold anomalies in the mining area from Devonian to Triassic. The gold-bearing background value of the Lower Devonian Pojiao Formation is 1.85ppb, and the ore-bearing lithology is silicified pyrite argillaceous siltstone and silty mudstone, and the adjacent area is gold-bearing layer.

Middle Devonian (D): The gold-bearing background value is 1. 15ppb, and the ore-bearing lithology is silicified biolimestone and silicified reef limestone.

Lower Devonian Pojiao Formation (Dp): grayish green shale, dark gray shale, calcareous mudstone, silty mudstone and fine ~ silty sandstone. Pyrite containing authigenic and semi-authigenic crystals. It made a top top for Tokyo wild vegetables and so on. The outcrop is 20m thick. Neighboring areas include Muli in Guangnan, Daliantang and Dang Ge in Funing, which contains antimony and gold deposits.

Upper Permian Shishan Formation (Ps): equivalent to Dachang Formation, with a gold-bearing background value of 2.55ppb. The ore-bearing lithology is pyrite-bearing siliceous rocks, silicified aluminum clay shale and silicified tuffaceous shale. Changxing Formation and Suo Na Formation are silty mudstone, argillaceous siltstone and layered tuff. Emeishan basalt formation consists of basalt and tuff.

There are two kinds of ore-bearing beds in the mining area.

The first type occurs in the clastic rocks of Banna Formation in the fracture zone, which is lenticular and layered, with a length of 25~ 175 m and a thickness of 0.9~ 19. 1 m ... mainly pyrite, arsenopyrite, stibnite, trace sphalerite and chalcopyrite; Gangue minerals are mainly timely and calcite. Wall rock alteration includes silicification, pyritization, arsenopyrite and stibnite mineralization. Pyrite is mainly pentagonal dodecahedron and arsenopyrite is needle-shaped. Arsenopyrite and pyrite are the main carrier minerals of gold.

The second type occurs in tuff, silty mudstone and tuffaceous siltstone of Permian Changxing Formation and Suo Na Formation in the fault zone. The surrounding rock is silicified and pyritized, with mineralization thickness greater than 7m and gold grade of 0.35 ~ 1.48g/ ton. It belongs to disseminated gold deposit.

② There is a certain relationship between the structural ore control and the display of gold mineralization.

Fold: Obvious (Longlao) anticline is dominant, with Devonian as the axis, Permian as the two wings and Triassic as the periphery. The wings are asymmetrical, with a steep north wing of 45 and a gentle south wing of 25. The axis of anticline extends to the west, and its axial plane is slightly inclined to the south and partially inclined to the north. The hub is wavy, dislocated by faults in the central part of the anticline and replaced by faults in Xilonglao-Shishan area. On the other hand, in addition to some large faults, some small-scale secondary inclined folds with axes parallel to the faults are common.

Four groups of fault development:

East-west faults: represented by Shishan-Hanyuan-Shang Tang fault, there are few faults, which are compressive and torsional, strike parallel to the axis, and the section is inclined to the north with an inclination of 70 ~ 75. The fault zone is wide, the fractured rocks in the zone are directional and silicified, and the stratigraphic fault distance is 50~ 1 10m. Silicification along the fault, local pyritization, with gold anomaly.

NE-trending faults: represented by Zena-Saiya-Pingzhai fault, there are many faults with long extension, and most of them are high-angle compression and compression-torsion flat inference layers. The profile is inclined to the east, the fracture zone and its shear bandwidth are narrow, and the alteration includes silicification, pyritization, arsenopyrite and carbonization, which shows good gold anomalies and is a favorable metallogenic place.

C) NW-trending fault: represented by Limon-Biaotai-Shang Tang fault, which is the largest in number and long in extension, often runs through the whole area, and is a high-angle compression-torsion fault with a NW-dipping cross section. The strata contact on both sides of the fault changes greatly, and the width of the fault zone is unequal, and the shear bandwidth reaches100 ~ 200 m. The alteration of fault zone and shear zone is mainly silicification and pyritization, with common carbonization and abnormal gold, which is a favorable metallogenic place. In addition, there are NE-trending faults and W-trending faults in the mining area, which have no obvious control effect on gold mineralization.

③ Relationship between magmatic rocks and gold mineralization.

Magmatic rocks in the mining area are mainly late Permian basalts, which are thick in the south and thin in the north, thick in the east and thin in the west. The eastern part is dominated by dense massive basalt, the southern part is dominated by volcanic breccia, dense basalt and agglomerate, and the western and northern parts are dominated by pyroclastic rocks mixed with basalt. The dense basalt in Bi Li area is rich in sodium, poor in potassium and magnesium, and slightly high in aluminum. The abundance of gold in basalt is 7.02ppb, which provides a certain gold source for gold enrichment and mineralization.

…………

I don't know how long it took, but when the surrounding scenery turned dusk, I saw an old three-wheeled motorcycle coming at a high speed, and a piece of flying dust was set off behind it. The road is not wide, so I lean over and let it pass first. Suddenly, I saw the back seat and held out a hand to greet me. I looked at it strangely. It turned out to be my friend Lao Yang in the mine.

It turned out that yesterday he heard that I was coming to the mine, and I rode my bike to 1 1 point overnight and arrived at the former Bodanshan mine section. There was a plan to have lunch here, but I didn't know that Mount Bodan was not on my walking route. Then the phone doesn't know my specific location. He helped me pack my things. I got on the bus and the wheels slipped when I walked up an uphill. The three of us can only push the cart forward. Finally, I went back to class, ate stewed chicken in a restaurant called Nongjiale and asked for some vegetables.

Well, at home, today should be the first good sleep in days. Sleep well.

In my dream, I walked on a familiar mountain road. The fog overhead winds on both sides of the road like smoke, and the winding path is secluded. I vaguely think that thing is called time. I walked so far in the mine from dawn to dusk. Time and tide wait for no man, I forgot all those "impossible" excuses and stuck to the "possible" reason.

Hard-working, the fog cleared, and there was a blue sky in front.