Through1:20000 soil survey,1:kloc-0/0000 geological survey,1:kloc-0/0000 high-precision magnetic survey,1:5000 IP step profile, IP sounding and trench exploration,
1 Pb-Zn (mineralized) body is distributed in line 27 to line 32, with a northeast trend, with a length of more than 1600m and a width of 2 ~ >; 10m, inclined to the southeast. Lead-zinc-silver mineralized bodies occur in the fault contact zone between Devonian marble and Cretaceous Yingan breccia tuff.
Figure 5-56 953 Apparent Amplitude Frequency and Apparent Resistivity Profile Plan of High Terrain
The surface of the western section of lead-zinc ore body 1 is controlled by three projects: TC27- 1, TC23- 1 and TC 15-2. The controlled length is more than 300m. The thickness of the mineralized body is 2-2.4m, and the ore grade is Pb 0.1. The IP survey and electrical sounding data of lead-zinc ore bodies show that the contact zone between Devonian marble and Cretaceous Yingan breccia tuff is steep to the north. By arranging ZK 1701and ZK 1702 holes on the exploration line17, it is confirmed that the volcanic rock cover is thin, and there are cracks at the fracture contact between Devonian marble and Cretaceous Yingan breccia tuff.
Figure 5-57 Geological Profile of No.953 Exploration Line in Gaodi Gold Mine
Figure 5-58 As-5 Abnormal Diagram of Sediment Measurement in Jifeng River System
1 The eastern surface of lead-zinc ore body is controlled by TC 10- 1, TC 16- 1 and TC 24-2, and the control length is more than 600 m m m. The surface shows that there is a large diabase in the contact zone between Xingen Formation of Upper Carboniferous and volcanic rocks of Upper Kuri Formation of Lower Cretaceous. It includes massive, veinlet pyritization and galena mineralization. Deep drilling confirmed that lead-zinc-silver ore bodies were found in holes ZK80 1, ZK802, ZK 160 1 and ZK240 1.
I- 1 Pb-Zn ore body: It is located in ZK80 1 hole, with an apparent thickness of 2m (Figure 5-60), and occurs in the contact zone between calcareous phyllite and quartz diorite in breccia, with ore grade of Pb0.46% and Zn 0.92%-2.47%.
I-2 lead-zinc ore body: located at ZK80 1 hole 127.50 ~ 128.50m, with apparent thickness1m; Ore grade: Pb0.63%, Zn 1. 17%, Cu0.35%, Ag 15.9g/t, which occurs in the contact area between calcareous phyllite of breccia and tuffaceous siltstone (Figure 5-6 1).
Figure 5-59 Geological Schematic Diagram of Jifeng Lead-Zinc-Silver Mine
Figure 5-60 Jifeng ZK80 1 Hole 22m Lead-zinc Core
Figure 5-6 1 Jifeng ZK80 1 Hole 128m Cu-Pb-Zn Core
I-4 lead-zinc ore body: located in hole ZK240 1, 236.8 ~ 242.3 meters, with an apparent thickness of 5.5 meters, with an average grade of 0.24% lead and 0.62% zinc. The host rock is dacite tuff. The metallic minerals are pyrite, sphalerite and galena, which are disseminated, veined and lumpy in the broken dacite tuff.
I-7 lead-zinc ore body: located in ZK240 1 hole 340.0~344.4m, with an apparent thickness of 4.4m and an average grade of Pb0.34% and Zn0.57%. The host rock is dacite tuff. The metallic mineral is mainly sphalerite, with a small amount of galena distributed in the broken dacite tuff in the form of stars or disseminated. Silicification of surrounding rock and epidote alteration are strong.
I-8 lead-zinc ore body: located at ZK240 1 hole 360.0 ~ 364.5m, with an apparent thickness of 4.5m, an average lead grade of 0.25%, a zinc grade of 0.9 17%, and a maximum zinc grade of 2. 12%. The host rock is dacite tuff. Metal minerals are mainly sphalerite and a small amount of galena, which are distributed in massive or veinlets in the tuff of fractured dacite. The boundary between ore body and surrounding rock is not very clear, but a gradual relationship. The footwall of the ore body is a fault fracture zone, and pyrite, galena and sphalerite can be seen.
The ore is a medium-fine disseminated dense lump, which can be divided into galena-sphalerite-chalcopyrite type and molybdenite-chalcopyrite type according to different mineral combinations. According to the degree of oxidation, it can be divided into oxidized ore (within 10m from the surface) and primary sulfide ore. The metal minerals are mainly galena and sphalerite, and the associated metal minerals are chalcopyrite and molybdenite. Galena, sphalerite and chalcopyrite are mostly in semi-automorphic or heteromorphic crystalline state, with particle size between 0.09 and 0.2 mm, and the content of galena and sphalerite is generally lower than 0.5%.
Lead-zinc (mineralized) body ⅱ occurs in Cretaceous strongly silicified dacite tuff and is controlled by TC 15-2 single ditch project. It is inferred that the length is 200m, the thickness of mineralized body is 4 ~ 15m, and it occurs in layers with dip angle of 130, dip angle of 63 and grade of Pb 0.08%. The extension of mineralized bodies has not been systematically controlled.
Lead-zinc ore body Ⅲ occurs in Cretaceous strongly silicified dacite tuff, and is controlled by four gullies: TC 15-3, TC 0- 1, TC 0-5 and TC 4- 1. The estimated length is 700m and the thickness of ore body is 4 ~ 65438+. Dual-frequency IP survey and electrical sounding data show that there is a high polarization anomaly at the depth of line 0 of the ore body, and its amplitude and frequency are between 2.5% and 4.0%. Electrical sounding data show that the occurrence of highly polarized body is steep, slightly inclined to the north and extending downward. The depth of the ore body is controlled by holes ZK 10 1 and ZK 102, and no industrial ore body is found in the corresponding designed ore body. Only in ZK 102 hole, there are strong sphalerization and galena mineralization at the footage of 19.2 ~ 42.50 meters ... lead reaches 0. 14% and zinc reaches 0.30%. Pyritization, limonitization, manganese mineralization and sericitization are closely related to mineralization.
Ⅳ lead mineralized body is controlled by TC 16- 1 single project. The width of mineralized body is 6m, and the average lead grade is 0.66%. Produced in Carboniferous argillaceous and carbonaceous slate, the rock is strongly discolored and silicified. Seasonal lentiform veinlets and seasonal veinlets with a width of 2 ~15 cm are parallel to the bedding plane. It contains massive veinlet pyrite and galena.
In 2009, AP5-2 gold anomaly was exposed to the south of No.40 exploration line, and TC40- 1 and TC40-2 exploration trenches were constructed, and high-grade gold bodies with certain thickness were found (Figure 5-62).
TC40-2 trough width: ⅴ- 1 .00m/orebody, grade of Au2.84g/t, Ag11.2g/t. The northern part of the orebody is not closed, so it needs further recourse. Ⅴ-2 orebody width 1.4m, grade of Au5.36g/t and ag 3.55g/t. ..
Tc40- 1 trough: ⅴ-3 orebody width 1.00m, gold grade11.5g/t; Ⅴ-4 orebody width 1.0m, grade Au36.5g/t, Ag283g/t and Pb0.90%.
20 10 controlled the width of gold ore body and its extension to northeast and southwest, and constructed TC36- 1, TC36-2, TC36-3, TC44-2, TC48- 1, TC48-2 and TC40-4 troughs.
In the breccia tuff of TC36- 1, there are 9m wide silicified, pyritized and kaolinized alteration zones (Figure 5-63), and 1 gold ore body: Au 0.66 ~ 1.70g/t is found at 33 ~ 35m.
Figure 5-62 Geological Schematic Diagram of Gaodi Gold Mine in Jifeng 967
Figure 5-63 Jifeng TC36- 1 trough mineralized breccia tuff
TC40-3 tank: 37.9m is used for tank cleaning, and 26 pieces are used for basic analysis. The lithology is crystalline lithic tuff, in which there are fine disseminated and powdery pyritization and a small amount of epidote. Rock joints are developed, with iron and manganese pollution along the joint fracture surface and occasional sphalerization. The analysis of grooving samples shows three AuAgPbZn mineralized bodies (Table 5- 1).
Table 5- 1 Analysis (wB) Results of TC40-3 Notched Samples in East Area of Jifeng Forest Farm
Tc44- 1 tank: 60.4m tank cleaning, 59 pieces of basic analysis. The lithology is mainly crystalline tuff, with occasional gravel tuff (Figure 5-64). Rock joints and fissures are developed at 55 ~ 60.4 m, which are filled by late siliceous veinlets with a density of 5 ~ 6 /m, and galena and sphalerite are found in the siliceous veinlets. There are also fine pyrite and limonite. Local kaolinization and epidotization. Analysis of grooving samples shows three AuAg ore bodies (Table 5-2). The gold grade at 56 ~ 57m is as high as 157g/t, and the exploration of Gaodi gold deposit in Jifeng 967 needs further development.
Table 5-2 Analysis (wB) Results of TC44- 1 Notched Samples in East Area of Jifeng Forest Farm
Fig. 5-64 Gold mineralized crystalline tuff in TC44- 1 trough in the east of Jifeng Forest Farm.
In order to understand the scale and prospecting prospect of high-grade gold ore body in Jifeng 967 highland, a 1∶ 10000 soil geochemical survey was conducted in the southeast of Jifeng on 20 10 (Figure 5-65). 1:10000 soil survey circled the high value position of Au, which appeared on exploration line 40. The anomaly is distributed in the northeast, 500 meters long and 40 ~ 180 meters wide. The combination of abnormal elements is Au-Ag-As-Sb-Pb, and the general content of gold is (40 ~ 80)× 10.
Fig. 5-65 Abnormal map of soil AuAgPb element in Jifeng survey area (isoconcentration line (wB) content: Au: 5× 10-9,10-9, 20× 10-9, 50× Ag:0.5× 10-6， 1× 10-6，2× 10-6，5× 10-6； Pb:50× 10-6 100× 10-6200× 10-6500× 10-6)
Five Ag-Pb-Zn anomalies with large range and high anomaly content were also found in the investigation area, which were distributed in the northeast and northwest directions respectively, among which Ag-5 and Ag-4 had the largest anomaly range and the highest anomaly intensity. Ag-5 is unusually long1200m and wide100 ~ 500m. It is composed of Ag-As-Sb-Pb, and the contents of each element are: Ag (0.5 ~ 3.5) × 10-6, Pb (60 ~ 266). Ag-4 is 900m long and 40 ~ 180 m wide, and is composed of Au-Ag-As-Sb-Pb. The element content is Ag (0.7 ~ 1.5) × 10-6, As (39 ~/kloc-).
Suggestions on the next prospecting work in Jifeng Pb-Zn-Ag-Au target area;
1) 1 Pb-Zn-Ag mineralization zone is located in the contact zone between Devonian marble and Cretaceous dacite tuff, which has been confirmed by drilling holes on Line 8, 16 and Line 24. Lead-zinc polymetallic ore (mineralized body) is thin and its ore grade is not high, so it is not necessary to continue to pursue and explore.
2) Due to the large sedimentary thickness of the surface slope in Jifeng area, the bedrock has not been exposed when the exploratory trench reaches 3m, which will affect the determination results of the basic analysis samples and lead to low analysis results. The high-grade data of 157g/t found in the 20 10 cleaning of TC44- 1 trench shows that it is possible to obtain more realistic data by increasing the trench exploration depth. Therefore, it is suggested to inspect the trench exploration in this section, deepen the trench exploration to expose the bedrock, and re-sample to obtain accurate data.
3) Verify five Pb-Zn-Ag anomalies found in the 20 10 soil survey, select high-value anomalies for trench exposure, find new Pb-Zn-Ag-bearing mining areas, and select the best ones for deep verification.