Settlement exploration

Ashele copper deposit in Xinjiang is a concealed massive sulfide deposit related to volcanic genesis. Located in the east of Ashele Village, 3 1km northwest of Habahe County, Xinjiang. 1984, the geophysical exploration unit of the fourth geological brigade of Xinjiang Bureau of Geology and Mineral Resources carried out natural electric field measurement and induced polarization measurement, and found the hidden deposit after discovering the natural electric field abnormality and induced polarization abnormality, which was verified by drilling. However, its discovery is the result of close cooperation and joint research with the comprehensive survey methods of geology, geophysical prospecting, drilling and scientific research in the metallogenic prospect area delineated by previous geological surveys. Electrical prospecting has played a guiding role.

1955- 1956, the 13th geological brigade of the Ministry of Geology conducted a regional geological survey of1:200,000 in the Habahe area, and found the Bugule copper deposit [1], which is located between the Habahe River and the Bugule River at the elevation of 1002. The direction is about 2km, and the geographical coordinates are 86 20' 40 "east longitude and 4817'10" north latitude. 1966, the regional geological survey brigade of Xinjiang Geological Bureau compiled and published1:200,000 Habahe sheet mineral map and sheet description based on the geological and mineral data of the 13th geological brigade in Habahe area. 1:200,000-scale mineral map indicates the copper deposit and barite deposit, and Caratas Mountain is classified as Grade I or above in the range including the deposit. Caratas Mountain is the name of the mountain in the southeast of Bugule copper mine, and Bugule is the name of the nearby river. Bugule copper mine is now Ashele copper mine. At that time, there were no residential areas in this area. 1960 After emigration, a residential area was established and named Ashele Village. It is pointed out in the description of the mine map that "the ore bodies occur in tuff, tuff sandstone, limestone and chlorite schist in the Lower Carboniferous Qisi Formation in caral (C 1k)". Now it is changed to the next Middle Devonian Ashele Formation (D 1-2a). Due to tectonic stress, the rock strata are broken into blocks extending in the north-south direction, and many strongly pyritized fracture zones appear between or at the edges of the blocks. In some areas, there are breccia, silicification and ochre, and the rocks are rich in malachite, followed by minute rhodochrosite and barite.

A regional geological survey of1:200,000 was carried out in this area, and a metal survey of1:200,000 was also carried out. From the general situation of the region, the contents of tin, copper and lead are relatively high in some areas, such as the copper mineralization area on the right bank of Habahe River, 2km southwest of 1092 highland and Caratas mountain area. According to the discovered Bugule copper mine site, the metal content was determined at the mine site with an area of1.3×1.5km21:10000, and the copper content was determined to be 0. 1% and the lead content was 0.0/kloc-.

"According to the favorable conditions of tectonic geology, mineralization points of copper and lead, and the existence of individual hydrothermal mineralization zones, I-level prospect area of Caratas Mountain is delineated, and three suggestions are put forward:

(1) A geological survey and general survey with the scale of 1: 10000 was conducted in an area of about 35km2.

(2) The scale of 1: 10000 is measured in the same area, and the most promising area scale should be increased to 1:5000.

Figure 7- 1 Grade I polymetallic prospecting zoning map of Caratas Mountain

1- four yuan; 2- Carboniferous Caratas Formation; 3- Upper submember of Devonian Toksare Formation; 4— Lower submember of Devonian Toksare Formation; 5- granite; 6-vermilion/barite anomaly; 7-I level scenic spot

(3) Drilling to find out the mineralization in the depth of hydrothermal alteration zone. These hydrothermal altered rocks contain mineralization points of lead, copper and barite [2].

1960, Altay Geological Brigade of Xinjiang Geological Bureau conducted a geological survey at the scale of1:50,000 in Yushaxia-Ye Qi-Ashele area. At the same time, it also conducted a survey of metal quantity, heavy sand and radioactivity, delineated many anomalies, made a preliminary explanation, and evaluated the surface of ore points in the area, but there was no obvious progress in prospecting.

1964, the airborne geophysical exploration brigade of the Ministry of Geology carried out 1:65438+ million scale airborne magnetic survey in this area, aiming at finding ultrabasic rocks related to magnetic deposits and chromium deposits. Ashele copper mine is located at the edge of the exploration area.

1in may, 984, the sixth team of the fourth geological brigade of Xinjiang bureau of geology and mineral resources and the people's government of Habahe county conducted a ground inspection and evaluation of the barite mine exposed in Ashele, and found that the reserve of D-grade barite mine was more than 20,000 tons. 1983, Habahe County reported to the Geology Department of Xinjiang Bureau of Geology and Mineral Resources. The analysis results of a barite sample sent showed that the Pb content was 5. 12% and the Ag content was 20 1g/t, which attracted the attention of the Geology Department and informed the team to pay attention to this information. At that time, the geological team and brigade that inspected and evaluated the barite mine in this area decided to inspect the exposed iron cap near the barite mine. In August of that year, the Geophysical Exploration Team of the Fourth Geological Brigade sent geophysical exploration team members to conduct electrical profile exploration on the exposed iron cap on the surface. The natural electric field method and induced polarization method are used for the measurement, and the comprehensive electrical profiles of six sections (section spacing of 400m) such as 1, 16 and 48 lines are measured (see Figure 7-2).

Figure 7-2 Electrical Profile of Ashele Mining Area

Figure 7-3 Geophysical Exploration and Geological Profile of Ashele Mining Area 16 Line

1- drilling; 2— Lithologic profile boundary; 3- Geological boundary; 4- copper ore body; Zeta π-dacite porphyry; SQSL-secondary quartzite slate; SQ ζ π-secondary quartzite dacite porphyry; SL-slate； SQ- secondary quartzite; Bt- breccia tuff λ π-quartz porphyry; P-type fault zone; A- abnormal IP; B- apparent resistivity anomaly; C- abnormal self-electricity; D magnetic anomaly

Natural electric field method and induced polarization method found obvious self-induction and induced polarization anomalies on 1 and 16 lines respectively. The 16 line is the best anomaly, with a self-excited anomaly width of 300m, an anomaly intensity of-200mV, an induced polarization anomaly width of 300m, and an apparent polarizability of the largest anomaly of 13%. The position of natural electric field anomaly is basically the same as that of IP anomaly. At the same time, low resistivity anomalies were also observed in the self-induced and induced polarization anomalies, and the apparent resistivity was 50-100 (ω m) (see Figure 7-3). Anomalies of self-electricity and induced polarization were also observed on the 1 line 400 meters north of the 16 line, but the intensity of the anomalies weakened and the width increased. The self-induced polarization anomaly is 400 meters wide, the intensity is-100 millivolt, the induced polarization anomaly is gentle, and the apparent polarization rate is 8%. There are also low resistivity anomalies in the self-induced and induced polarization anomalies, and the apparent resistivity is 65438+. Soil investigation along the profile and surface iron cap sampling analysis show that copper element is abnormal, with high content in some areas, but no industrial ore body has been found.

Figure 7-4 Geophysical Exploration and Geological Profile of Ashele Mining Area 1 Line

1- drilling; 2. Geological boundary; 3— Lithologic profile boundary; 4- copper ore body; ξ π-dacite porphyry; β-basalt; SQ- secondary quartzite; Bt- breccia tuff; B B- tuff; A- abnormal IP; B- apparent resistivity anomaly; C- abnormal self-electricity; D magnetic anomaly

1984 10.30 Tan Lizhong, technical director of the Geophysical Exploration Team of the Fourth Geological Brigade, attended the symposium on geophysical anomaly verification held by Xinjiang Bureau of Geology and Mineral Resources in Urumqi, introduced the results of electrical profiling in Ashele area, and put forward three opinions on the work in this area:

(1) Carry out small-scale airborne geophysical survey in this area;

(2) Conducting1:50,000 electrical and geochemical exploration with an area of 500-700km2;

(3) 1:5000 scale electrical prospecting area is 3km2 in the exposed area of 1985 iron cap.

At that time, Tao, chief geological engineer of the local Bureau of Geology and Mineral Resources, and Deng Zhenqiu, chief geophysical engineer, studied the results of comprehensive electrical survey and related geological data in this area, and thought that there might be a certain scale of concealed sulfide ore bodies under the outcrop of the surface iron cap. 65438+1October 3 1 Report to Director Zhao Dachang and Chief Engineer Zhang, and put forward two specific suggestions:

(1) In order to determine whether the anomalies discovered by electrical prospecting are caused by hidden sulfide ore bodies or other non-mineral geological bodies, it is necessary to quickly find out the nature of the anomalies. It is suggested that the Geophysical Exploration Team of the Fourth Geological Brigade should immediately carry out supplementary gravity survey on the two sections of lines 1 and 16 where there are self-induced and induced polarization anomalies, so as to detect whether there are local gravity anomalies in the electrical anomaly positions.

(2) Two boreholes are respectively arranged at the abnormal positions of self-electricity, induced polarization and low resistance on the two sections of 1 line and 16 line, and the anomalies are checked by drilling engineering to find sulfide ore bodies that may be hidden.

The director and chief engineer agreed after listening to the report. On June 1 65438+1October1day, it was decided that Liu Dequan, director of the Bureau of Geology and Mineral Resources, would convene the Fourth Geological Brigade for implementation. Zhao Dachang pointed out that during the winter construction, the logistics department of the bureau allocated a car drill to the four battalions, and the financial department allocated additional construction costs and appropriately increased the field allowance. Upon receiving the notice, the Fourth Geological Brigade immediately arranged a geophysical prospecting team to carry out gravity survey along the profile, and the geological team transported the drilling rig and equipment to Ashele. In the process of implementation, gravity measurement was not carried out due to the failure of gravimeter. With the approval of the Bureau, the drilling project will be arranged directly according to the electrical prospecting data, and the geophysical prospecting team and geological team will jointly study it. Holes ZK 160 1 and ZK 1602 are arranged on the line 1, and holes ZK 1 0/are arranged on the line1. 165438+1At the beginning of October, the drilling rig and drilling equipment were transported to Ashele, but drilling could not be started because the mountain was closed by heavy snow.

1985, the fourth geological brigade arranged two drilling rigs for drilling. In addition to the above four boreholes, in order to solve whether the abnormal bodies caused by 1 and 16 lines are connected, ZK80 1 holes are arranged on the eighth line between 1 and 16 lines, and the spacing is1. Due to the need of barite survey, ZK70 1 hole is arranged on Line 7, north of 150m, and the drilling rig is used for construction first.

ZK70 1 hole was drilled on May 29th and ended on June 23rd, with the final hole depth of 350.4m and the designed hole depth of 150m.

Because the self-electricity and induced polarization anomalies are mainly located in the 16 line, another drilling rig is located in the 16 line to construct ZK 160 1 hole.

ZK 160 1 hole was drilled on June 3rd and ended on June 29th, with the final hole depth of 227.99m and the designed hole depth of 400m.

According to the local topographic conditions, after the completion of ZK70 1 hole, the construction of ZK 102 hole will be carried out.

The hole ZK 102 was drilled on July 6th and closed on July 27th, with a final hole depth of 357.46m and a designed hole depth of 350m.

After ZK 160 1 final hole, construct ZK 1602 hole.

ZK 1602 hole was drilled on July 9th and ended on August 7th, with a final hole depth of 450m and a designed hole depth of 450m. After the hole is formed, construct ZK80 1 hole.

The hole ZK80 1 was drilled on August 24th and closed on September 9th, with the final hole depth of 4 18.3m and the designed hole depth of 400m m..

ZK 102 hole is completed, and then ZK 10 1 is constructed.

ZK 10 1 hole was drilled on August 3rd and closed on September 2nd. The final hole depth was 396.96m and the designed hole depth was 400m.

1985 * * A total of 6 boreholes were constructed, with a total footage of 2401.11m. Copper-bearing pyrite bodies are found in all boreholes, and copper is poor, so copper bodies cannot be circled. See table 7- 1 for the occurrence of each borehole.

Of the six boreholes constructed in 1985, ZK 10 1 hole is the best. 1986 hole ZK 103+0065438 is constructed in the east of hole ZK 65438+75 1m, and the hole depth is 65438. At that time, it was considered that it was difficult to compare with ZK 10 1 hole, and geologists estimated that the ore body might tilt westward instead of eastward. ZK 103 has a hole depth of 430.4m, with three layers of copper, one layer with an apparent thickness of 1.45m and a copper grade of 2. 1%. The first layer is 8.99m thick and the copper grade is 3.53%. The thickness of the first layer is 3.6 1m and the copper grade is 1.55%. Therefore, ZK 10 1 hole is constructed to the west. The final hole depth is 476.95m, and there are five layers of ore: the first layer has an apparent thickness of 2.35m and a copper grade of1.83%; The apparent thicknesses of the other four layers are 22.03m, 2.42m, 33. 17m and 3.05m respectively, and the copper grades are 0.82%, 0.94%, 0.93% and 0.68% respectively. The drilling results of hole ZK 104 show that the copper-bearing ore body does not tilt to the west, because the depth of the ore body and the grade of copper ore seen in this hole cannot be compared with ZK 10 1 hole. On this basis, ZK 105 hole is constructed to the east of ZK 103 hole.

Table 7- 1 ZK70 1, ZK 102, ZK 160 1, ZK 1602, ZK10/kloc-0

In the same year, ZK802 tunnel was constructed in the east of ZK80 1 tunnel on Line 8. There are three copper (mineralized) bodies in the hole, with apparent thicknesses of 29.97m,13.57m and 2.09m respectively. The first two layers are massive pyrite, containing copper locally, and the last layer is densely disseminated with massive copper-rich pyrite layer.

In addition to lines 1 and 8, hole ZK 1603 will be constructed east of hole ZK 1603 on line16, and hole ZK2402 will be constructed on line 24. Pyrite bodies were found in these boreholes, but the copper content was very low.

1985 and 1986 drilling works, at the same time, the ground surface is exposed by exploratory trench between 1 line and line 36100 m. The results of trench exploration reveal that the surface mineralization is scattered and discontinuous, only a few samples can reach the cut-off grade, and the ore bodies cannot be connected.

Because the mining area is located in the structural fracture zone, the rock is broken, the drilling construction is difficult, and the copper-bearing pyrite body is complex, and the shallow sulfide ore body is poor in copper. After two years of surface exposure and drilling results, it is still difficult to determine the prospect of this deposit. People ask, geophysical prospecting and electrical prospecting are very good, why is it difficult to see ore when drilling? How to explain. Based on the survey of 1985 and 1986 electrical profiles, the electrical area survey (natural electric field method and induced polarization method) with the scale of 1:5000 was carried out in the mining area, and the induced polarization method found large-area IP anomalies at two abnormal centers. It is also found that the contour plane is oval with two abnormal centers. These two methods are generally consistent. According to the characteristics of anomalies, it is inferred that the line from 1 to 16 is a sulfide ore body that causes anomalies. The ore body inclines to the east, and the abnormal strength is different. It may be that the buried depth of different parts of the ore body is different, so it is necessary to insist on drilling. Through the research on the comprehensive control scheme of drilling in complex strata in mining area, the difficulties in drilling ZK 105 hole were overcome, and the final hole depth was 402.69m, with four layers of ore, and the cumulative apparent thickness was 84.01m. The four-layer copper deposits are 27.85m, 4.24m, 29.40m and 22.52m respectively, and the copper grades are 5.23%, 3.37% and 65,432 respectively. According to the geological research, it is considered that the ore beds seen in ZK 10 1, ZK 103 and ZK 105 can be classified according to the ore types, ore types, ore types, ore types, ore types, ore types, ore types, ore types, ore types, ore types, ore types, ore types, etc. ZK 103 hole breakthrough depth 154.49- 168.70m, ZK 105 hole breakthrough depth 30 1.45-329.3m), and it is determined that the ore body attitude inclines eastward. After geological, geophysical, scientific and drilling research, it is decided to construct ZK 107 hole east of ZK 105 hole at 1987.

From August of 1987 to August of 10, ZK 1 07 hole was constructed on1line, and the final hole depth was 651.85m. A copper-rich body with apparent thickness of 178.72m was found, with the highest copper content.