The mining area is 2000 meters long and 0/000 meters wide, covering an area of 2 square kilometers. Sporadic rock outcrop distribution. There are three Indosinian strong compact folds and NE-trending faults in the mining area. In the late Yanshan period, granodiorite porphyry intruded along Qixia Formation. There are 5 1 ore bodies in the two ore belts extending to the northeast. The main ore body (1) is located at the interface between Qixia Formation and Gufeng Formation of Lower Permian, and the secondary ore body (No.3) is located at the interface between Gaolishan Formation of Lower Carboniferous and Huanglong Formation of Upper Carboniferous. The ore body is layered and saddle-shaped. The ore body is 500- 1000 m long, 50-600 m deep and 3-1/m thick. 1 and No.3 ore bodies account for 63.5% of the copper reserves of the deposit. Other ore bodies occur in irregular veins in the contact zone between intrusive body and surrounding rock, in structural cracks and fault zones, and in xenoliths at the edge of intrusive body. All ore bodies strike northeast, tend to southeast, and the dip angle changes greatly. There are two types of ores: copper-bearing pyrite and copper-bearing molybdenum skarn. The main minerals are chalcopyrite, molybdenite, pyrite and chalcocite, followed by galena, sphalerite, magnetite and bismuthite. Gangue minerals mainly include garnet, diopside, wollastonite, dolomite, serpentine and talc. There are many beneficial associated components, besides gold and silver, there are also selenium, lead, zinc, tungsten, cadmium and platinum group elements. The washability of ore is very good. The recovery rates of copper and molybdenum in skarn-type ores are 94.45% and 82.23% respectively, and the recovery rates of copper and sulfur in copper-bearing pyrite-type ores are 85.84% and 79. 12% respectively. The deposit should belong to skarn type and sedimentary-hydrothermal superimposed transformation type.
There is an ancient excavation pit on the eastern slope of Xiaotongshan at the southern end of the mining area, with a small scale and unknown mining age. During the period of 1958, Shen Guangbei and Wang Minghua, the fifth team of Southeast Anhui Geological Team of Provincial Geological Bureau, made two field trips in May and July, and wrote the Investigation Report of Xiaotongshan-Shibanlu Mine in Shuangqiao Township, Yicheng County, Anhui Province. According to the report, the Xiaotongshan copper mine is a skarn type with a small scale and an estimated grade of less than 0.3%, but further work is needed. The iron ore between Shiban Road in Xiaotongshan is hematite with high silicon content. The next step should be to find primary ore. According to the survey opinions, in August-65438+February of the same year, Wang Minghua once again carried out geological work on Xiaotongshan Copper Mine. After surface exploration and shallow well pursuit, in June,1958+February, it submitted the Evaluation Report of Shuangqiao Xiaotongshan Copper Mine in Xuancheng County, Anhui Province. According to the report, the ore body is small in scale, with a very irregular small convex mirror shape. The ore body is 30 meters long, 4 meters wide and 30 meters deep, with a grade of 1% and a calculated copper reserve of 90 tons. It is considered that acidic igneous rocks contact with timely sandstone, and the prospect of the deposit is not great.
1958 in the second half of the year, under the slogan of the whole party and the whole people, the masses spontaneously mined copper and iron ore in the intrusive contact zone of Xiaotongshan ancient mine pit and Shiban Road. The mined "iron ore" is limonite with high silicon content and weathered limonite skarn, which is still piled up beside the mine.
In the mid-1960s, Team 322 of the Provincial Geological Bureau shifted its focus from the area along the Yangtze River to the south of Anhui Province according to the instructions of its superiors. At the beginning of 1965, most of the geological technicians of Team 322, led by team leader Hu Shusheng, participated in the field investigation and inspection in southern Anhui mining area. After screening, it is considered necessary to carry out further work on the Magushan copper mine site. 1965 in may, Magu Mountain copper mine inspection team was established, and soon it was expanded to the second detachment of No.322 team, with Qiu Deqin as the technical director of the detachment. Through geological mapping, it is found that there are two northeast-extending alteration zones at the bottom of Huanglong Formation and the top of Qixia Formation. The intrusive body in the north has a certain scale, and the granodiorite porphyry is strongly altered along the contact zone, and there are intermittent limonite skarns along the contact zone. Through systematic sampling analysis, silver, copper, lead and zinc are highly abundant. It is preliminarily recognized that the structure in this area is complex; The rock mass is a medium-acid small rock mass, which is in contact with the limestone of Qixia Formation. The silicalite of Gufeng Formation is the floor of skarn, which plays a shielding role and is beneficial to mineralization. There is copper mineralization in some parts of the surface, and skarns are distributed intermittently in a certain scale, so this occurrence may be promising. Because of the wide coverage of Quaternary system on the surface, it is necessary to understand the deep ore-bearing property in order to carry out further work. Therefore, in July of 1965, ZK80 1 borehole was designed and constructed on Line 8. Two layers of skarn copper deposits with a thickness of 5.54m and 7.04m and one layer of skarn molybdenum deposits with a thickness of13.86m were discovered in the contact zone in the first borehole, and the systematic geology of the deposits began.
In the early stage of general survey, prospecting in contact zone was mainly carried out by means of drilling matching trough, well exploration and geophysical and geochemical exploration. Although the occurrence rate of ore in the general survey hole is very high, it is too late to make a correct judgment on the occurrence prospect of ore because of the thin coal seam, complex mining structure and great problems in ore body correlation and connection. Two breakthroughs in the understanding of the prospecting stage affirmed the scale of the deposit: ① Through repeated and meticulous core rechecking, the bottom conglomerate with a thickness of only about 10cm was finally found at the bottom of Huanglong Formation, and epidote sandstone was found in the middle of Gaolishan Formation as a marker layer for stratigraphic correlation; (2) Based on the comprehensive analysis of geological and geophysical data and the spatial characteristics of mineralization and alteration, and inspired by the emerging stratabound theory in China, the prospecting idea is extended from the contact zone to the horizon, and the interface between Gufeng Formation and Qixia Formation and the interface between Gaolishan Formation and Huanglong Formation are determined as two ore-controlling horizons. These two breakthroughs in understanding not only clarified the dense folds and complex fracture system in the deposit, but also solved the problem of seam correlation and connection, found the main ore body, increased the reserves of the mining area sharply, and affirmed the scale and prospect of the deposit. 1966 began to do geophysical and geochemical exploration in mining areas, and the input methods include comprehensive electrical method, magnetic method and secondary halo. 1966,65438+February, Cao Shunzu and others compiled the Geophysical and Geophysical work briefing of Magushan Work Area in Xuancheng, Anhui Province, and1968,65438+1October submitted the Supplementary Geophysical Report of Magushan Work Area. The results of magnetic method and secondary halo provide valuable information for understanding the mineralization characteristics and expanding the prospect of the deposit.
1In September, 1969, under the auspices of Qiu Deqin, technical director of the detachment, the Report on General Survey and Evaluation of Magu Copper and Molybdenum Deposit in Xuancheng County, Anhui Province and the Exploration and Design of Mining Area were submitted. In this report, copper ore and molybdenum ore are delineated respectively according to general industrial indicators, and the reserves of 10 ore body with industrial significance are calculated: 88,000 tons of copper (oxidation+primary), 0.6 tons of molybdenum10000 tons and 9.34 million tons of sulfur ore. In the second half of the same year, it turned to exploration, and drilling was the only prospecting method. The exploration types are classified as III-IV, among which copper-bearing pyrite-type ore bodies are classified as III, and the C-level reserves are calculated as 100× 80- 100 m; Skarn-type Cu-Mo deposits are classified into Class IV, and the C-level reserves are calculated to be 50× 60-80m. During the exploration, it is found that the above grid can't control the change of ore bodies. According to the situation that the main ore bodies and secondary ore bodies are III-IV (transitional) types, the grid is adjusted to 50× 70- 100 m to calculate the C-level reserves. From 65438 to 0979, and from 65438 to February, Qiu Deqin compiled and edited the Geological Exploration Report of Magu Mountain Copper-Molybdenum Deposit in Xuancheng County, Anhui Province. The main personnel who participated in the exploration of the deposit and the compilation of the report were Sun Huadong, Qiu Anjing, Bian Yucai and Zhang Zhaofeng. Reserves submitted in the exploration report: 86,000 tons of primary copper, 0.4 million tons of copper oxide/kloc-0, 0.8 million tons of molybdenum1./kloc-0, and 5.862 million tons of sulfur ore. In addition, the reserves of associated components such as gold, silver, lead, zinc, tungsten, bismuth, iron, sulfur (elements), selenium, cadmium, rhenium, platinum, palladium and hunger 14 were calculated.
198 1 year 65,438+February 28th, Anhui Mineral Reserves Committee approved reserves: 86,000 tons of copper,1./kloc-0,800 tons of molybdenum and 5,783,000 tons of sulfur ore; Associated gold 1.89 tons, silver 307.33 tons and sulfur (element) 262 1.0000 tons. The copper oxide reserves submitted in the exploration report were not approved because of low recovery rate and difficult separation.
The investment in general survey and exploration is estimated to be 4.07 million yuan. 286 boreholes, with a total workload of 75,500m. The exploration cost is 0.02 tons of copper, 0.003 tons of molybdenum and 1.42 tons of sulfur (ore) per yuan.
The general survey of the Magushan copper-molybdenum deposit began at the beginning of 1965, and was converted to exploration in 1969. The geological exploration report was submitted in 1979, and the exploration period reached 14 years, which spanned the whole civil strife period of the Cultural Revolution 10. The shortcomings in the exploration of mineral deposits are all branded with the times. For example, during the exploration, in order to ensure the iron ore resources after the expansion of Masteel, the superior instructed to hold an iron ore battle in Wuhu-Maanshan area. Because of this, some or all of the drilling rigs explored in Magu Mountain mining area have been moved to the Iron Mine Club War Zone for many times, which makes the exploration of copper and molybdenum deposits in Magu Mountain intermittent, even completely stopped at 1973 for about a year; Another example is that the deposit has entered the exploration stage, but the industrial counterpart has not been found for a long time, and the industrial indicators have not been issued for a long time, resulting in a long exploration period. In addition, because the No.322 team has no tunnel construction means, it tries to improve the exploration degree by intensive drilling. Practice has proved that it is difficult to obtain advanced reserves and improve the exploration degree for III-IV deposits without tunnel verification.
1988 "Xuanzhou Magu Mountain Copper and Molybdenum Mine Command" was established to be responsible for the preparation and command of mine infrastructure. At present, the mine with a design day of 350 tons is under intense infrastructure construction. Magu Mountain copper (molybdenum) deposit is the largest nonferrous metal mine in southeast Anhui. Its discovery is the result of the silent dedication and hard work of the vast number of geologists in Team 322 of the Provincial Bureau of Geology and Mineral Resources, and its mining will certainly contribute to the economic prosperity of Xuanzhou.