Types and examples of mineral deposits worthy of deep prospecting in Nanling and surrounding areas

The mines in Nanling and surrounding areas that have been included in the national crisis mine resource replacement project include: Jiangxi Quannan Dajishan Tungsten Mine, Dayudangping Tungsten Mine, Dingnan Kaimeishan Tungsten Mine; Guangxi Fozi Chong lead-zinc mine, Nandan Tongkeng tin polymetallic mine, Rong'an Siding lead-zinc mine, Gongcheng Limu tin mine; Guangdong Shaoguan Yaoling tungsten mine, Shirenzhang tungsten mine, Dabaoshan polymetallic mine; Hunan Yaogang Xian Tungsten Mine, Shuikoushan Lead-Zinc Mine, Huangshaping Lead-Zinc Mine, Baoshan Lead-Zinc Mine, Dongpo Lead-Zinc Mine, etc.

Whether it is a mining area that has been listed as a crisis mine or not, it is difficult to say that "resources are exhausted." To this end, the deep prospecting issues of some important types of deposits in Nanling and surrounding areas are briefly discussed here.

1. Sedimentary metamorphic deposits

1. Metamorphic volcanic rock type massive sulfide deposits——Xiqiu style

Xiqiu copper in Zhejiang The ore (Figure 1-10) is a metamorphosed marine volcanic rock type massive sulfide deposit. In the past, drilling control depth has reached nearly a thousand meters, but the ore body has not been pinched out. The ore body is continuous from -200m elevation to -700m elevation. And the thickness is increasing, and the downward extending trend of the ore body has not changed. Unfortunately, the drilling technology at that time was no longer able to catch up (exploration ended in August 1973).

Figure 1-10 Cross-section of Xiqiu Copper Mine, Zhejiang (quoted from Huang Chongke et al., 2001)

Since this type of deposit belongs to the marine volcanic sedimentary type, its ore body generally belongs to Layered, layer-like and lenticular, and there may be multiple cycles, that is, multiple ore-bearing layers appear due to the multi-cycle nature of submarine volcanic eruptions. The location of the ore bodies in each ore-bearing layer may not necessarily be the same as that of the same one. Corresponds to the center of the volcanic eruption, so lateral migration is possible. Judging from the current level of control, the extension length (current vertical depth direction) of the No. 1 ore body of Zhejiang Xiqiu Copper Mine (accounting for 95% of the total deposit reserves) may reach 1km. Compared with similar ore bodies in the world, It can also be said to belong to the longest category, but whether there are more layers needs further exploration. In addition, the surface control length of the Xiqiu Copper Mine is about 1000m. Therefore, if the extension length is greater than 1000m, the extension direction of the ore body is essentially its length direction, while the NE length direction of the surface is its width direction. Other similar ore bodies whose depth is longer than the surface length include Hongtoushan in Liaoning, Ashele in Xinjiang, Fuziba in Gansu, and rare mines in Yunnan. The total surface length of the Hongtoushan industrial ore body in Liaoning is about 550m, but the slope depth controlled by the project is more than 1,500m, which is equivalent to three times the surface length. The No. 5 ore body (lens-shaped) in Shanxi Hujiayu has a strike length of 60 to 160 m, a maximum thickness of 49 m, and a dip depth of 500 m; the No. 3 saddle-shaped ore body has a strike length of 130 to 200 m, and a dip depth of >600 m. Shanxi Zizigou No. 2 ore body has a strike length of 500m and a dip extension of more than 1000m. The length of the No. 1-3 ore body of the Dahongshan Iron-Copper Mine in Yunnan is greater than 7000m. There is also the possibility of discovering blind ore bodies in deep areas, such as Paiziba in Wenxian County, Gansu Province (Table 1-10).

Table 1-10 The length and thickness of the main ore bodies of volcanic rock type massive sulfide deposits at home and abroad

The typical volcanic rock type massive sulfide deposits in the Nanling area have not yet been confirmed, but Nor can we deny the possibility of its existence. For example, one opinion is that the Qingtang pyrite deposit in southern Jiangxi is a hydrothermal type, and another opinion is that it is a sedimentary metamorphic type related to ancient volcanic activity. However, in any case, the issue of deep ore prospecting is worth noting.

2. Sedimentary metamorphic iron ore——Xinyu type

Xinyu type iron ore is one of the most important types of iron ore in Nanling area, with Yangjiaqiao iron ore in Jiangxi as the represent. This deposit is the deposit with the largest proven iron ore reserves in Jiangxi Province (more than 200 million tons).

The iron ore layer is produced in the shallow metamorphic rocks of the Yangjiaqiao Formation of the Songshan Group in the upper Sinian System. The mine is divided into two mining sections. The main ore seam is 1,400m long and 800m wide. Its thickness varies greatly, generally 1.5 to 15m thick, with an average thickness of 10.56m. The ore body is band-shaped and lentil-shaped on the plane; the shape is complex on the cross-section, showing layered, layer-like, "xiang" shape, step shape and mushroom shape (Figure 1-11). In the Yangpo ore section, the ore body is 1380m long, 450m wide, 14.19m thick, with an inclination angle of 50° to 70°, and the ore body is layered. In other ore sections, the ore body is 7300m long, 450m wide, 19.68m thick, with an inclination angle of 50° to 70°, and the ore body is layered.

In 1957, the 309 aerial survey team of the Ministry of Geology conducted aeromagnetic surveys in central Jiangxi and discovered two magnetic anomaly zones with strengths of 500-1500γ and 500γ respectively. From 1958 to 1961, the former 907 Geological Team of Jiangxi Geology Bureau conducted geological exploration and verification in the Yangjiaqiao area of ??the first magnetic anomaly zone, and discovered the Yangjiaqiao iron deposit. As can be seen from Figure 1-11, the deepest exploration depth in the Yangjiaqiao area is only 363.70m. Since the implementation of the Crisis Mine Resource Replacement Project from 2006 to 2009, 14,008.57m of drilling has been completed in the Liangshan Iron Ore Area, and a total of 25.36 million tons of iron ore resources have been added. Among them, in Line 1 of the Liangshan mining section, the original drill hole has a maximum depth of 276.65m, and the deep hole of the Crisis Mine Resource Replacement Project reaches 629m, but the ore body has not actually disappeared (Figure 1-12).

Figure 1-11 Geological section of line 53 of Yangjiaqiao Iron Mine

2. Carbonate rock host type copper-lead-zinc deposit

1. Layered Skarn-type copper-zinc deposit—Lama type

The Lamo zinc-copper polymetallic deposit is located in the contact area between the Longxanggai rock mass and the Devonian strata in the middle of the Dachang Tin polymetallic ore field ( Figure 1-13). The ore-bearing surrounding rocks are mainly wide-strip limestone and lentil limestone of the Devonian Wuzhishan Formation, followed by siliceous rock of the Luojiang Formation and argillaceous limestone of the Luofu Formation. Mineralization is mainly controlled by the structure of the contact zone, and the mineralization elements are mainly Zn and Cu, accompanied by Sn, Ag, Au, etc. The ore body is mainly distributed in the outer skarn belt on the west side of the rock mass, which is equivalent to the lenticular limestone layer and striped limestone layer of the Upper Devonian. The latter is strongly skarnized, marbleized and angular. Lithification. The ore bodies are produced in a layered-like manner, maintaining the original lentil-like and strip-like structure. The occurrence of mineral seams generally trends 30° to 80°, tilts NW, and has an inclination angle of about 20°. Some mineral seams extend up to 700m and are 1.8 to 3.8m thick.

The entire Lamo mining area and even the entire surrounding area of ??the Longxanggai rock mass (Figure 1-14) has a very strong metasomatic mineralization, because in addition to the development of skarn-type zinc metasomatic along the layers In addition to copper deposits, there are even layered granitic rocks that originate from metasomatic processes (Wang Denghong, 1992). During the special implementation of the resource prospecting for crisis mines, some layered hidden metasomatic ore bodies were discovered between Yulamo and Tongkeng, such as No. 95 ore body and No. 96 ore body. The burial depth of the ore body has exceeded 800m, but no rock mass has yet been seen. Therefore, the potential for deep prospecting still exists.

2. Layer-vein composite lead-zinc deposit - Fankou type

The Fankou lead-zinc deposit in Guangdong was once regarded as a typical layer-controlled type in the Nanling area Lead-zinc deposits have also been carried out along-layer prospecting work based on the prospecting ideas of layer-controlled deposits. Although this deposit is one of the backbone lead-zinc mines in my country, its retained reserves have not decreased but have continued to increase since it was put into operation in 1968 (according to the Mine Geological Survey Section). The reason is that new ore bodies are constantly being discovered in deep places, and newly discovered Ore bodies are often produced along faults, such as along the F3 fault (Figure 1-15). It can be clearly seen from Figure 1-15 that the Fankou lead-zinc deposit is not a single layered ore body, but is replaced and filled along the layers under the premise of controlling the fault zone. Although there are different understandings of syngenetic faults and epigenetic faults about the nature of steeply dipping faults such as F3, and there are still controversies between syngenetic and epigenetic faults as to the origin of ore bodies, no matter what the view is, the potential of deep mineral prospecting cannot be denied. . Since the implementation of the special project to replace resources in crisis mines, Fankou Lead-Zinc Mine has increased the amount of lead-zinc metal in the deep and edge parts by 620,000 tons.

Figure 1-12 Geological Section 1 of the Liangshan Mine Section in Liangshan Iron Mine Area, Jiangxi Province (quoted from the "2008 Annual Results Report of the National Crisis Mine Replacement Resource Prospecting Special Project", 2009)

Figure 1-13 No. 13 geological longitudinal section of the Lamo Skarn zinc-copper deposit (according to Chen Yuchuan et al., 1993)

3. Karst filling type tin-lead-zinc-antimony polymetallic deposit— ——Longtoushan (100# ore body) style

The 100# ore body in the Longtoushan area of ??Dachang, Guangxi is unique in the world from every angle. The ore body extends spirally from the near surface (680m above sea level) to a depth of -185m and still has no major changes. In the past, during the exploration process, we did not think that the ore body was spiral, so the ore body was discontinuous on the section line (Figure 1-16), but in fact it is continuous (Figure 1-17), and it is likely to be related to the deep The 105 ore body is a whole and is worthy of deep prospecting. In May 2009, the construction of the deepest solid mineral exploration deep hole in Guangxi began (known as the "No. 1 Geological Deep Hole in Guangxi"). The hole was located in the Dongfenglong area, and the purpose was also to detect the mineralization in the deep.

Figure 1-14 Plane geological map of the 530m middle section of the Lamo zinc-copper deposit (according to Wang Denghong, 1992)

Figure 1-15 Cross-section map of the Fankou lead-zinc mine in Guangdong (according to the Song Dynasty Shuhe, 1989)

Figure 1-16 Line 4 reef profile of Dachang deposit (according to Song Shuhe, 1989)

Figure 1-17 Longtoushan 100, Dachang, Guangxi #Schematic diagram of the ore body model (yellow is the rock wall)

3. Fractured zone altered rock type gold-silver deposit

1. Fractured zone altered rock type in the basin depression area Gold and silver mine——Changkeng-Fuwan Style

Guangdong Sanshui Basin and surrounding areas contain oil, natural gas, oil shale, gypsum, rock salt and bentonite, coal, cement limestone and other energy and Regarding non-metallic mineral resources, a series of metal deposits have been discovered since the 1980s, including the Changkeng large gold mine and the Fuwan super large silver mine. In addition, there are some smaller metal deposits, such as Nanpengshan medium-sized manganese mine, Xiqiaoshan small silver mine, Hengjiang small lead mine, Hecun small lead-zinc mine, Chashan small lead-zinc mine and Lipianshan niobium-tantalum mine, Dayaoshan Polymetallic Mineral Mine, Jilingang Gold and Silver Mineral Mine, Luzhou Silver-Lead-Zinc Mineral Mine, Dieping Silver Mineral Mine, Songbaikeng Pyrite Mineral Mine, Xi'an Farm Silver-lead Mineral Mine, and Tiegang Polymetallic Mineral Mine Point, Lunyong lead-zinc mine point, Gaotan pyrite point, Qingyundong lead-zinc mine point, etc.

Among these deposits, those related to granite include lead, zinc, silver and gold deposits; those related to volcanism include silver, niobium and tantalum deposits; those related to basin fluid effects include gold, silver, lead-zinc, uranium and molybdenum deposits. Related to epigenetic processes are manganese, iron and placer gold deposits (such as the Danzao area). Among them, the deposits directly present in volcanic rocks include the silver deposits and niobium-tantalum deposits in Xiqiao Mountain, which all belong to the "Sanshui-Luoding, Guangdong Province" The metallogenic series of silver polymetallic deposits in the basin are related to magma-fluid interaction" (Wang Denghong et al., 2005a). Although the Changkeng Gold Mine and Fuwan Silver Mine in Guangdong were newly explored in the past 20 years, the deep parts of the Fuwan Silver Mine (one of the largest independent silver mines in my country) still have prospecting potential (Figure 1-18). In recent years, the Changkeng large-scale gold mine, Fuwan super-large silver mine, and Hengjiang, Chashan and other lead-zinc mines have been discovered in the Sanshui Basin in Guangdong and its western margin Sanzhou Basin. In order to find out the metallogenic age of the Hengjiang lead-zinc-copper deposit, this paper used two different methods and measured the formation age of quartz in the Hengjiang lead-zinc-copper deposit in two different laboratories to be 35 Ma (fluid inclusion Rb-Sr Isochrone method) and 36~39Ma (40Ar/39Ar fast neutron activation method), the two are basically consistent, indicating that the polymetallic mineralization occurred in the Oligocene, later than the Changkeng gold deposit (136Ma±) and Fuwan Silver mine (65Ma±. Du Junen et al., 1996; Wang Denghong et al., 2005a). Recently, it was found that the copper content in the Hengjiang lead-zinc mine is also very high. The result of the ICP-MS measurement of the sample was 18.39%, and the result of the spectroscopic examination was 19.72%. Microscope identification mainly includes chalcopyrite, chalcocite, sphalerite and galena. Therefore, the existence and enrichment of copper mineralization provides important new clues for the geological prospecting of precious metals and non-ferrous metals in the Sanshui Basin and surrounding areas, and also opens up new ideas for searching for non-ferrous metal deposits in other basin areas.

Figure 1-18 Cross-section of Changkeng Gold Mine-Fuwan Silver Mine in Guangdong (according to Wang Denghong et al., 1999)

2. Altered rock type gold deposit in the fracture zone of metamorphic rock area ——Hetai type

As one of the largest independent gold deposits in the Nanling area, the Hetai gold deposit is located in the NE-to-NE end of the Yunkai uplift area of ??the South China Orogen and the NNE of the Guangning-Luoding fault zone. The intersection of the Wuchuan-Sihui fault zone. The deposit is strictly controlled by the Hetai ductile shear zone, and the deposit is produced in the secondary structural mylonite zone or structural fissures of the ductile shear zone. The ore-bearing stratum is the Sinian Lechang Group, which is composed of a set of overall disordered metamorphic rocks. The lithology is composed of quartz sericite schist, dimicite quartz schist, metamorphic granulite, gneiss, migmatite, and migmatite. Mainly, the area has suffered strong ductile shear metamorphism to form the mylonite series of rocks. The Hetai gold deposit is produced in the mylonite series of rocks. Hercynian medium-grained biotite monzogranite and biotite plagioclase granite are exposed in the west of the mining area; the northeastern part of the mining area is intruded by the Yanshanian Wucun giant porphyritic biotite granite.

Judging from the current level of control, the deep parts of the river platform undoubtedly have prospecting potential. In the past, the depth controlled during mining exploration was only about 400m. Therefore, the "second" prospecting space at depths from below 500m to 1000m is very worthy of exploration (Figure 1-19).

Nanling and surrounding areas are of the same type as the Hetai gold mine, including the Jinshan gold mine in Jiangxi, and many of its deep parts also have prospecting potential. The mineralization conditions are similar, but there are more mineral deposits associated with multi-element gold deposits, such as the Woxi-type tungsten-antimony-gold deposit.

3. Fenghuangshan type silver deposit in the broken zone of the dome area——Fenghuangshan type

The Fenghuangshan silver deposit is a large-scale independent vein discovered in the late 1980s. Silver deposits. It is located on the northeast side of Fenghuang Mountain at the junction of Long'an County and Fusui County in Guangxi. It belongs to the Caledonian fold system in South China, the Youjiang fold belt, and the Daming Mountain uplift in the west. The Fenghuangshan silver mine is located in the Luyushan anticline in the northern part of the Damingshan complex anticline in Guangxi. The ore body is controlled by a fault fracture zone that strikes nearly EW and dips south. The exposed strata in the mining area are Cambrian, and there is Lower Devonian in the northern periphery (Figure 1-20). The Cambrian is a set of deep flume-basin-like flysch deposits. The ore body occurs in the Cambrian Huangdongkou Formation. Judging from the current degree of control, it is possible to find new ore bodies in the deep ore bodies of the Fenghuangshan mining area or the ore bodies such as I-① and II-① themselves may extend downward (Figure 1-21).

Figure 1-19 Joint section of the exploration line of Hetai Gold Mine in Guangdong (data from Guangdong 719 Team, cited from Luo Zhenkuan et al., 1993)

Figure 1-20 Fenghuangshan Silver Mine in Guangxi Simple geological map (quoted from Huang Chongke et al., 1997)

Figure 1-21 Cross-section of No. 8 exploration line of Fenghuangshan silver deposit (according to Chen Hai et al., 1997)

Figure 1 -22 Sectional view of the Dachang antimony deposit in Qinglong, Guizhou (according to Song Shuhe, 1989)

2. Gently inclined antimony deposit in carbonate rock area - tin mine type

Xikuang Mine is the most famous antimony mine in my country and the world. The output characteristics of its main ore body are similar to those of the Qinglong Dachang Antimony Mine in Guizhou. It also has a near-horizontal layered pattern with fractures between two different lithological strata. Belt (Figure 1-23). It is obvious from Figure 1-23 that, in general, the burial depth of the antimony ore body is shallower than 300m, and its northwest side is restricted by the F75 fault zone, but there is actually room for deep ore prospecting on its southeast side.

At present, there are still different understandings of the origin of various properties of fracture zones and faults in mining areas and their ore-controlling significance. However, whether they are formed before or after mineralization, that is, whether they are ore-guiding structures or damage and dislocation of ore bodies, Or mineral layers will have an impact on geological prospecting, especially deep prospecting. Since the implementation of the special project to replace ore prospecting for crisis mine resources, a total of 17 boreholes have been constructed from 2006 to 2008, and an additional 53,000 tons of 333-grade antimony metal has been added to the No. IV orebody controlled by the Qiziqiao Formation deep in the F75 fault.

Figure 1-23 Geological profile of line 31 of the Xikuang antimony deposit (according to Song Shuhe, 1989)

3. Steeply inclined tungsten antimony gold deposit in clastic rock area—— — Zhazixi type antimony deposits

Different from the tin mine type antimony deposits, the Zhazixi type antimony deposits are produced in shallow metamorphic clastic rocks (rather than carbonate rocks). On the other hand, the ore body It is a steeply inclined vein, similar to a "five-story" quartz vein type tungsten mine. It can be seen from Figure 1-24 that the vein group is distributed in a "torch" shape. A single vein body is controlled by a fracture and fracture zone, and the ore bodies in the same fracture and fracture zone can be pinched out and reappeared.

5. "Five floors + basement" type high-temperature hydrothermal quartz vein type tungsten polymetallic ore

1. "Basement"-based quartz vein type tungsten ore—— —Damingshan style

The Damingshan tungsten mine is located in the north of Dongliangjiang Township, northeast of Wuming County, Guangxi. It is 55km away from Wuming County and has convenient transportation. It is said that the deposit was discovered by fellow villagers in 1936, but the geological work was mainly carried out after 1949. From 1960 to December 1962, the 272 Geological Team of Guangxi Metallurgical Geological Exploration Company exposed the layered wolframite deposit, and then conducted a detailed investigation of the layered fine-vein disseminated wolframite deposit from Qifeng to Heli. Through systematic control of large vein-type tungsten deposits and granite medium-fine vein tungsten deposits, we discovered fine-vein belt-type tungsten deposits hidden in the Cambrian sandy rocks under the Devonian cover. As of April 1967, China's proven reserves of tungsten trioxide were 160,200 tons.

The Damingshan mining area is located at the northwest dipping end of the Damingshan box-shaped anticline, and its main structure is the Qifeng anticline. Faults are developed in the area and magma activity is frequent. Biotite granodiorite, quartz porphyry, fine-grained granite, porphyritic muscovite granite, aplite, etc. are exposed. Porphyritic muscovite granite is closely related to wolframite deposits (Figure 1-25).

The main industrial types of tungsten ore that have been identified in the mining area include: ① Quartz network vein type wolframite: produced in the upper part of the porphyry muscovite granite body in Qifeng area, composed of fine wolframite quartz veins , 400m long, 55-75m thick, and the vein density is generally 15-25 lines/m2; ② Quartz veinlet type wolframite: distributed in the Cambrian strata, mostly blind mines covered by the Devonian system, consisting of many A group of wolframite quartz veinlets with different occurrences, generally distributed in a small range, containing 0.2% to 0.4% tungsten dioxide; ③ Quartz-wolframite large vein type: generally thicker than 10cm, mostly distributed outside muscovite granite In the Cambrian and Lower Devonian sandstones in the contact zone, a small amount is distributed in granite. 35 large veins have been discovered in the Shigao section, with lengths generally ranging from 100 to 300m, sloping depths from 100 to 250m, vein thicknesses from 0.1 to 0.57m, and tungsten trioxide content generally ranging from 0.45% to 1%. More than 10 large veins have been discovered in the Heli section, which are generally large in scale, but the ore is relatively poor, containing 0.05% to 0.21% of tungsten trioxide; ④ Fine network veins resemble layered wolframite type: distributed in the section from Qifeng to Heli , mainly concentrated in the axis and wings of the Qifeng anticline, is produced in the middle to fine-grained argillaceous quartz sandstone of the Lower Devonian Lianhuashan Formation. In individual sections, it is found in the upper quartz fine sandstone and the lower part of the Nagaoling Formation. in shale. The ore body is produced in a layered or layer-like manner, generally 1 to 3 layers, in a laminated form, and its occurrence is consistent with the surrounding rock. It is 2,000m long along the strike, has a controlled slope depth of 300m, and has a thickness of 12 to 40m. Mainly composed of striped ores, the ore composition is simple, and the WO3 content is generally between 0.1% and 0.5%, with little change. The ores near muscovite granite are richer and contain higher molybdenum.

Figure 1-24 Line 0 section of Hunan Zhazixi Antimony Mine

Mining and survey work in recent years also found that in addition to the development of typical five-story upright quartz in the Daming Mountain area Vein-type tungsten ore (Figure 1. Large vein-type quartz vein-type wolframite ore in the middle section of 400m, the vein has been extended into the granite rock mass) and rock-type tungsten ore (Figure 2. Rock-type tungsten ore in the middle section of 400m, with scheelite In addition to mineralization (characteristics of mineralization), contact zone network vein type (Plate 3. Network vein quartz vein type tungsten ore in the surrounding rock in the middle section of 320m) and gently tilting or even near-horizontal output (Plate 4. Gently in the surrounding rock in the middle section of 320m) are also developed. Inclined quartz vein type tungsten ore, including both scheelite and wolframite), quartz vein type tungsten ore, the four have certain zoning characteristics in space (upright quartz vein type tungsten ore can penetrate the rock mass and contact zone; Gently inclined and vein-type tungsten deposits are mainly produced in the contact zone, while rock-type tungsten deposits are mainly produced within the rock mass), but they are all produced around the Yanshanian granite rock mass, forming a "four-in-one" mineralization pattern. Generally speaking, the difference between the Damingshan tungsten deposit and the quartz vein type tungsten deposits in southern Gansu is that the layered and layered ore bodies (including gently inclined quartz vein type tungsten veins) are more important than the steeply inclined quartz vein type tungsten deposits. Tungsten veins. In other words, the meaning of "basement" may be more than "five floors", which is clearly visible in the tunnel photos and the 42-line exploration profile (Figure 1-26).

Figure 1-25 Simplified geological map of Damingshan tungsten mining area (according to Li Shuiru et al., 2008)

2. “Five-story” mainly quartz vein type tungsten polymetallic deposit— ——Tao Tin Pit Style

See Chapter 4 for details. Although judging from the current control situation, the "basement" in the Taoxikeng mining area is not very developed, its existence cannot be denied, nor can we deny the possibility of superimposing multiple phases of "five floors".

6. Rock-type tungsten-tin-molybdenum-bismuth polymetallic ore

1. Porphyry molybdenum ore—bead-top type

Western Guangdong The Kaiyuanzhuding copper-molybdenum deposit is a large-scale copper-molybdenum deposit with huge potential economic value discovered by the 719 Geological Team of the Guangdong Geological Exploration Bureau in Fengkai County in 2005. The deposit is located on the Yuanzhuding Mountain in Fengkai County, Zhaoqing City, in the Yuexi-Guidong metallogenic belt, and the ore body extends to a depth of about 300m. After more than two years of field work, each exploration stage of the mining area from general survey to detailed survey was completed, and the deposit was initially evaluated as a large porphyry copper-bearing molybdenum deposit. On October 10, 2007, the "Detailed Investigation Report on Copper-Molybdenum Mine in Yuanzhuding Mining Area, Fengkai County, Guangdong Province" completed by the 719 Geological Brigade officially passed the review and acceptance by the Resource Reserve Review Center of the Ministry of Land and Resources, and finally determined that the deposit was a large-scale Copper-molybdenum deposits. At present, the proven amount of molybdenum metal is 260,000 tons, and the amount of copper metal is 980,000 tons##.

Chen Fuwen and Li Huaqin et al. conducted a relatively systematic isotope dating of the Yuanzhuding mining area and obtained the SHRIMPU-Pb age of the granite porphyry body as 132±5Ma (95% confidence, MSWD=1.6, N=8) and 151±16Ma (95% confidence, MSWD=3, N=3) (zircon samples were collected from the ZK-23-120 borehole in the mining area, with cores between 236 and 241m deep); obtained The Re-Os isochron age of molybdenite is 155±5Ma (the sample was collected from the ZK12-112 borehole in the mining area, with a hole depth of molybdenum mineralized ore between 284 and 313m).

Figure 1-26 Exploration line profile of Damingshan tungsten ore high-mining area 42 (according to Li Shuiru et al., 2008)

Yuanzhuding mining area may currently be the largest porphyry type in South China In the copper-molybdenum mine, there is no large area of ??rock mass exposed on the surface of the mining area, and it is a hidden rock mass. However, geochemical anomalies of Pb and Cu have been delineated in the past. In addition, there are many gold deposits and geochemical and heavy sand anomalies of Cu, Pb, and Au in the periphery, so the area has a high possibility of expanding resource potential (Figure 1-27).

2. Porphyry-quartz vein type copper-molybdenum-tungsten deposit——Kunlunguan type

Kunlunguan rock body is a relatively key rock body in South China, mainly composed of fine- It is composed of medium-grained porphyritic biotite granite and fine-grained porphyritic biotite granite. There are still different understandings of the structural environment of its formation, but the characteristics of being located at the intersection of regional NE-trending and NW-trending faults and the NW-trending Tianma-Luwei fault and dislocating the rock mass have always left a deep impression on people.

There is a copper-tungsten deposit within the Kunlunguan rock mass and its contact zone, namely the Wangshe copper-tungsten deposit in Binyang County, Guangxi, which is called in the 1:200,000 Nanning mineral map. For the Takata Copper Mine. The deposit has a mining history of nearly a hundred years, and mining relics such as Laodong are clearly visible. However, in the past, quartz vein type copper deposits were mainly mined, and the degree of research on the deposit itself was very low. The ore bodies are mainly produced in the form of veins in the Kunlunguan granite and occur in NW and NE joints near large faults. Tungsten ore is most closely related to fine-grained porphyritic biotite granite.

The Kunlungguan granite body is a remelting intrusive rock body in the middle and late Yanshan period. It is produced as a rock with a long axis in the NW direction. It is a complex rock body, divided into the main body and the late supplementary intrusive body. Those are in a mutation contact relationship. The lithology of the rock mass is complex. The main lithology is medium to medium coarse-grained biotite granite. The lithofacies differentiation is obvious. From the interior to the edge, the potassium feldspar decreases and the plagioclase increases. The lithology of the late intrusion is fine-grained. Biotite granite, diorite porphyry, aplite, etc. are the main surrounding rocks of ore bodies and are closely related to mineralization. For example, fine-grained biotite granite is the main surrounding rock of tungsten-bearing quartz veins and reticular copper-tungsten deposits. Rock; copper-bearing tungsten grenades often develop around and near diorite porphyry veins, and the two are closely related in space. Fissure structures are developed in granite, mainly in NW and NE directions, which are the main ore-controlling fissures, followed by NNE, NWW, EW and SN directions (Figure 1-28). Tungsten-bearing quartz veins are mainly produced in fine-grained biotite granite. They are mostly filled along NW and NE trending faults and are controlled by multiple sets of fractures. Along the trend of the vein, there are phenomena of branching and compounding, pinch-out reappearance and pinch-out side appearance. The ore minerals are mainly wolframite, followed by scheelite, pyrite, chalcopyrite, molybdenite and a small amount of natural bismuth; the supergene oxidized minerals include tungsten, molybdenum, malachite, limonite and foam. Bismuth ore, etc.; the gangue minerals are mainly quartz, followed by muscovite, etc. The ore is mainly in the form of histoid-semi-euhedral grains and disseminated structures.

Figure 1-27 Simplified geological map of the round bead top porphyry copper-molybdenum deposit in Fengkai, Guangdong (modified from the 1:200,000 Wuzhou regional geological map)

In the past, Wangshe The understanding of copper-tungsten ore mainly focuses on the vein-like ore body, so it is determined that it is a "quartz vein type" tungsten ore, and the characteristics of the vein-like ore body are clearly shown on the relevant drawings. However, in fact, in addition to the "five-story" tungsten-bearing quartz veins similar to those in southern Jiangxi and the Daming Mountains, there are also disseminated mineralization and irregular vein-like mineralization in the rock mass, and the mineral types have also expanded. Mainly copper and molybdenum (Plates 5-8).

For this reason, Wang Denghong et al. proposed the understanding that porphyry copper-molybdenum deposits may exist in the area, and suggested that in addition to looking for the Damingshan-style "five-story + basement" type tungsten deposits in this area, attention should also be paid to the porphyry type tungsten deposits. Evaluation of copper-molybdenum ores.

On March 20, 2008, Wang Denghong and others conducted underground inspections and found that mineralization of Cu, Mo and W was visible in the mining area, and the visual estimates were that the contents were above the cut-off grade. These three elements can all be mined independently. Existing analysis results show that the average grade of Cu is above 0.3%, and Mo and W also reach industrial grades. It is recommended to carry out comprehensive analysis, especially the analysis of Au content. The industrial type of the deposit should be positioned as porphyry copper-molybdenum ore, superimposed with quartz vein-type tungsten ore. There are two main tungsten-bearing quartz veins, both less than 50cm wide. They contain wolframite and scheelite, as well as metal sulfides such as molybdenite and bismuthite. The quartz veins themselves are zoned, with muscovite on the outside. In the middle are sulfide and wolframite, as well as geodes. Radial black tourmaline is found in some quartz veins. The reason why the main mineralization type is located in porphyry copper deposits is based on the following basis: ① The rock mass is mainly biotite granite, but interspersed with granite porphyry. The macroscopic boundary between the two is often clear but the actual boundary is unclear. , showing the characteristics of "hidden explosion"; ② The mineralization is mainly in the form of disseminated veinlets. The occurrence of veinlets is diverse and not fixed in one direction. Generally, the number of veinlets is more than 10 within a range of 1m, and the total vein width It can reach more than 5cm. Mineralization is seen both in the vein and outside the vein; ③ The metallic minerals are mainly chalcopyrite and molybdenite, and the particle size is generally fine and dispersed; ④ Alteration is developed, especially silicification and potashization. Silicified quartz is darker in color. At present, the height of the inclined shaft is controlled to be 50m, the length along the vein is controlled to be more than 300m, and the width is 100m±, but they are all within the mineralization range, and the prospecting potential is huge.

Figure 1-28 Geological sketch of the Gaotian section of the Wangshe copper-tungsten deposit in Binyang County (adapted from the 1:200,000 geological map of Nanning)

In view of the above understanding, it is recommended: ① Develop along the NW-trending fault zone, ② Carry out in-depth investigation at the intersection of NE-trending fissures and NW-trending main faults, and select rich ore bodies; ③ The type of deposit should be developed into porphyry type, that is, verify whether it has "low grade and large tonnage" Characteristics; ④ On the basis of surface expansion and deep drilling control, open-pit mining should be considered instead of underground separate mining of quartz vein type tungsten ore and copper ore; ⑤ Comprehensive utilization must be considered; ⑥ Strengthen mineral processing research; ⑦ Increase investment in exploration .

To sum up, there are many mining areas in Nanling and adjacent areas that are worthy of deep prospecting. In addition to the mining areas that have been included in the crisis mine replacement resource exploration plan (such as the Gejiu tin polymetallic deposit in Yunnan and Dongchuan Copper mines, Dushan Antimony Mine and Qinglong Antimony Mine in Guizhou, Tongkeng Tin Polymetallic Deposit, Fozichong Lead-Zinc Mine, Siding Lead-Zinc Mine and Limu Tin Mine in Dachang, Guangxi, Huangshaping Lead-Zinc Mine in Hunan Heyaogangxian tungsten mine, Yaoling tungsten mine, Shirenzhang tungsten mine, Shiyou copper-molybdenum mine and Dabaoshan polymetallic mine in Guangdong, Shilu iron mine in Hainan, Dajishan, Kuameishan, Danping, etc. in Jiangxi Tungsten mine, Zhilingtou gold mine in Zhejiang, etc.), there are many more to list. Here we recommend the Fankou lead-zinc mine in Shaoguan, Guangdong, the Yushui copper pit in Meixian, the Kirin factory in Huize, Yunnan, and the old factory in Lancang Lead-zinc mines, Damingshan Tungsten Mine in Guangxi, Changkeng Gold Mine-Fuwan Silver Mine in Guangdong, Houjiangqiao Lead-Zinc Mine in Hunan, Xiqiu Tongkeng in Zhejiang and other "crisis" or non-"crisis" mining areas should all Strengthen deep prospecting work.