The administrative division of the forecast area of Zhusileng Harkhan is under the jurisdiction of Tween Golsumu in Ejina Banner, Inner Mongolia, and its geographical coordinates are east longitude10235' 00 "~10242' 00" and north latitude 4 1 34' 30 "~ 4 1 46544. The traffic in the pre-investigation area is convenient, 30 kilometers north of Alashan Zuo Qi-Ejina Banner Highway, and 50 kilometers west of Dalaihubu Town/Kloc-0.

The pre-investigation area is located in the northern edge of Badain Jaran Desert, with low mountains and hills (Plate V-5). The altitude is generally 900 ~ 1000m, and the highest peak is the blue seamount of Zhusileng, which is 1 150m. The pre-investigation area belongs to a typical continental arid climate, with windy and little rain all year round, with annual precipitation of 50mm and evaporation of 4000mm, with rainfall concentrated in July and August. The highest temperature in summer is above 45℃, the highest surface temperature is 60℃, and the lowest temperature in winter is -30℃. The daily temperature difference varies greatly. The pre-survey area is vast and sparsely populated, the surface vegetation is sparse, the water source is scarce, and the production and life are extremely difficult.

The Zhusileng Harkhan Pre-survey Area is a copper and gold pre-survey area discovered by Inner Mongolia Land and Resources Exploration Institute at 2001:200,000,1:50,000 and 65,438+0: 25,000 on the basis of previous geochemical anomaly verification. Generally speaking, the work in the pre-investigation area and its periphery is relatively low. Predecessors mainly engaged in regional geological and hydrogeological surveys from 1950s, and did not carry out mineral geological surveys in this area until the end of 1990s. On the basis of predecessors' work, we made a systematic geological survey (Ⅲ-3 and ⅴ-6 plates) in this copper-gold prospecting area, and tested some rock (ore) samples, which provided a scientific basis for finding and exploring concealed deposits.

Second, the metallogenic geological environment

The pre-survey area is located in the southern margin of Siberia plate, where the North China Platform meets the Tarim plate.

(1) stratum

The regional strata in the pre-exploration area belong to Ⅱ 6 stratum community in Beishan geosyncline area, which is dominated by Devonian, Carboniferous and Permian of Upper Paleozoic, with some Mesoproterozoic and Early Paleozoic. Mesoproterozoic is a set of shallow metamorphic clastic rocks and carbonate rocks, which are concentrated in Zhusilenghehan area. The distribution of Cambrian, Ordovician and Silurian in Lower Paleozoic is limited, mainly a set of marine carbonate rocks and metamorphic clastic rocks. Devonian is a set of clastic rocks, carbonate rocks and a small amount of volcanic rocks with shallow sea facies and alternating land and sea facies, while Carboniferous and Permian are widely distributed as a set of clastic rocks, limestone and intermediate-acid volcanic rocks with shallow sea facies and alternating land and sea facies. The abundant distribution of acid volcanic rocks in Devonian is a remarkable feature of strata in this era, which indicates that this area experienced large-scale magmatic eruption in Carboniferous and Permian.

(2) Structure

Regional fault structures are extremely developed, and there are two main groups: NE and NW. Among them, NE-trending fault structures are large in scale and intensively produced, ranging from tens of kilometers to hundreds of kilometers in length, and NW-trending fault structures are also intensively produced, with a small scale and a length range of 20-30 kilometers. The ne-trending fault structure is a secondary fault structure. In addition, faults in other directions, such as near east-west, near south-west, northwest and northwest, are not as large as the above two groups, and belong to secondary structures derived from the main fault structure.

(3) Magmatic rocks

Regional magmatic rocks are mainly intermediate-acid intrusive rocks in the late Hercynian period, which are widely exposed and occur in the form of bedrock or large rock plants, and are oval to nearly round. Besides Hercynian intrusive rocks, there are sporadic Yanshanian acid intrusive rocks.

Third, the geological characteristics of the pre-survey area

(1) Geological Survey of Northern Mining Area

1. Strata

See table 4-3- 1 for the stratum content in the pre-survey area. The main exposed strata are Devonian Xipingshan Formation, Wotuoshan Formation and Yikewusu Formation. The main rock types are shallow metamorphic clastic rocks, biolimestone and clastic rocks containing tuff (Figure 4-3- 1). The strata generally tend to the northeast, with an inclination angle of 50 ~ 70. Among them, this formation mainly intrudes into Wotuoshan Formation because of ore-bearing diorite porphyry and granite porphyry in the pre-survey area. Due to the influence of magma and fault tectonic activities, silicification and blueschism generally occurred in this formation, and the original rocks in some areas have been completely metasomatism and transformed into blueschist. The sandy limestone and biological limestone of Wotuoshan Formation exposed in the south of the pre-survey area are highly pyritized due to the action of hydrothermal solution in the later period.

2. Structure

There are two main groups of fault structures in the pre-survey area: NW-trending and nearly EW-NE-trending. The NW-trending fault structure is consistent with the strike of strata and dikes, and the fault length is 2 ~ 3 km. This group of faults is the most important ore-controlling structure in the pre-survey area, which obviously controls the ore body, ore-bearing rock mass and mineralization in the pre-survey area. The fault structure has two tendencies, southwest and northeast, with an inclination of about 70. The fault is tensile, and the fault with the same direction and anti-dip has the characteristics of * * * yoke fracture.

Table 4-3- 1 Summary of Strata in Zhusileng Harkhan Copper-Gold Exploration Area

The length of SW-NE faults is about 1km, and they are arranged in parallel. The fault tends to the southeast, and the dip angle is almost vertical, which has the nature of translation fault. The brownish-yellow secondary carbonate veins are filled along the fault structural plane and formed later than the NW-trending fault. In the pre-survey area, it shows the cutting effect on rock mass, ore body and mineralization zone, but the spatial displacement of the cutting body is not large. In addition to the above two groups of fault structures, secondary faults and fault structures with the same nature and direction are extremely developed, among which the NW-trending secondary faults partially form copper-rich bodies. The fine silicified copper veins in the pre-investigation area are related to the NW-trending fine fracture zone.

3. Magmatic rocks

Tonalite, granite porphyry and diorite porphyry are mainly exposed in the pre-investigation area, and the geological characteristics of each rock mass are briefly described as follows:

Tonalite is a small rock with nearly elliptical distribution, with an area of 0.5km2, which is located in the north-central part of the prediction area. The rock is of medium-coarse grain structure and massive structure, and the main mineral components are plagioclase, amphibole and biotite. The hydrothermal alteration of tonalite in the copper belt is intense (plates ⅸ-7 and ⅸ-8), amphibole and biotite are recrystallized to varying degrees in chloritization and Yanshi, and plagioclase is kaolinized and sericitized (plates ⅸ- 1 ~ⅸ-5, ⅸ-7 and ⅸ).

Granite porphyries are veined and appear in groups. The general trend of the pulse body is northwest, with a pulse width of several meters to ten meters, a width of 50 meters at the widest point, a length of several tens of meters and a length of several hundred meters to two kilometers. The vein body widens, narrows, branches, compounds, pinches out and reappears along the strike, and the local gradient is quartz porphyry. Granite porphyry is porphyry structure and massive structure. The phenocrysts include plagioclase, potash feldspar and syenite, in which plagioclase and potash feldspar are sericitized. The matrix is timely and sericite, in which sericite is the product of alteration of feldspar minerals. The granite porphyry in the prediction area is generally pyritized star-shaped and influenced by thermal fluid. Granite porphyries located near the 1 ore body and in the copper mineralization zone are generally copper mineralization, epididymitization and carbonation. There are chalcopyrite and chalcopyrite at the edge of granite porphyry.

Diorite porphyrite occurs in veins, and the two veins strike northwest. The porphyrite dike located in the west of the pre-survey area is I- 1 ore body, with a length of 430m, a width of 24m, a width of 3m and an inclination of 70 degrees. The western end of the vein is hidden under sandstone and limestone strata and gradually pinches out eastward along the strike. The diorite porphyrite located in the middle of the prediction area has a pulse width of 500m and a width of 70 ~ 80m. The diorite porphyrite was strongly altered by hydrothermal solution, and its original structure has completely changed. The mineral composition is mainly epidote, chlorite, carbonate, timely and pyrite. Diorite porphyrite is the main ore-bearing rock mass in the pre-investigation area. According to its local characteristics, it is likely to be dominated by concealed bodies, and only some rock masses are exposed to the surface.

Figure 4-3- 1 Geological Schematic Diagram of Zhusileng Harkhan Copper-Gold Prospecting Area and Its Surrounding Areas

1- four yuan; 2- Cretaceous; 3- Upper Triassic; 4- Lower Permian; 5- Xipingshan Formation of Devonian; 6- Devonian Wotuoshan Formation; 7- Devonian yikewusu formation; 8- Upper Silurian; 9- Upper Ordovician; 10-Upper Cambrian; 1 1- Middle Cambrian; 12- Upper strata of Mesoproterozoic jujube hill Group; 13- Zhongyan Formation of Mesoproterozoic Mesoproterozoic jujube hill Group; 14- Hercynian tonalite; 15- Hercynian granite; 16- granite porphyry vein; 17- copper vein; 18- Fault

Except for the Hercynian period in tonalite, the formation time of the other two intrusive rocks is not clear because there is no isotopic age data. According to their interpenetration, the relative time sequence of these three intrusive rocks can be roughly determined. From morning till night, their formation sequence is: tonalite → diorite porphyry → granite porphyry.

(II) Geology of South Mining Area

1. Strata

Mesoproterozoic siliceous limestone, silicified marble, metamorphic siltstone, sandstone, quartzite, phyllite and silicified marble are mainly exposed in the pre-investigation area (Figure 4-3- 1). The overall strike of the stratum is northwest, and the local strike is north and south. Due to the influence of fold structure, the general dip of strata is northwest and southwest respectively, and the dip angle is 50 ~ 75. Influenced by the late hydrothermal solution and fault tectonic activities, fractured carbonate veins and barite copper mineralization veins of different sizes appeared in groups in the pre-survey area. Silicified veinlets consistent with bedding are extremely developed in marble strata, and the time has the characteristics of secondary time in quartzite strata.

2. Fault structure

There are three groups of faults in the pre-survey area, which are NW-trending, nearly N-S-trending and NE-trending, among which NW-trending is dominant and the three groups of faults are densely arranged in parallel.

The NW-trending faults tend to the northeast with an inclination of 60 ~ 70, the NW-trending faults tend to the east with an inclination of 50 ~ 80, and the NE-trending faults tend to the northwest with an inclination of 60 ~ 70. Among them, the NNW-trending fault is compressive and torsional, and the NNW-trending fault is tensile. Three groups of faults in Zhusileng area combine to form the eastern end of Hulun Bai Xi-Zhusileng anti-S-shaped arc structure, and the No.2 mineralization zone is delineated in the southern pre-survey area, that is, it is located in the north-south fault composite zone in the northwest. In addition to fault structures, there are fold structures in the pre-survey area, but they are mainly folds in the clastic strata of Yuan jujube hill Formation.

3. Magmatic rocks

Hercynian tonalite and quartz diorite are mainly exposed in the prediction area, which is the same age as tonalite exposed in the northern prediction area. The rock mass appears in the form of rock tree, which is semi-circular with an area of about 10km2. The rock mass intrudes into the Yuanzaoshan Group, and the strata in contact with the rock mass are strongly silicified. In addition to tonalite and quartz diorite, many diabase veins are intermittently exposed along the low-lying areas in the southern prediction area.

Four. Geochemical characteristics of ore-bearing rock mass

In this work, a systematic rock geochemical survey was conducted on tonalite, a ore-bearing rock mass in the northern pre-survey area. The results of principal element analysis (Table 4-3-2) show that the content of SiO2 _ 2 is 6 1.45% ~ 66.84%, with an average of 64.63%( 1 1 sample). K2O content is 2.08% ~ 2.92%, with an average of 2.53%; Na2O is 3.32% ~ 4. 12%, with an average of 3.85%; The content of (K2O+Na2O) is 5.63% ~ 7.04%, with an average of 6.38%. K2O/Na2O is 0.5 1 ~ 0.76. The Na2O content of all samples is greater than K2O content. The value of A/NKC is 1.0 1 ~ 1.23, indicating that aluminum skips saturation. On the SiO _ 2-K2O diagram (Figure 4-3-2), all samples fall near the dividing line between "high potassium calcium alkali series" and "medium potassium calcium alkali series". The σ value of Rietmann index is 1.65 ~ 2.20, which belongs to calcium-calcium-alkaline series.

Table 4-3-2 Analysis Results of Major Elements of Ore-bearing Rock Mass in Zhusileng Harkhan Copper-Gold Exploration Area (wB/ 10-2)

The content of rare earth elements in representative tonalite samples is 85.29×10-6 ~130.18×10-6 (Table 4-3-3), with an average value of1/kloc-0. The ratio of (La/Yb)N ranges from 4.23 to 7.25, with an average of 6.03. The distribution pattern of rare earth elements is a set of curves inclined to the right (Figure 4-3-3), and the fractionation of light rare earth elements (LREE) and heavy rare earth elements (HREE) is not obvious. Δ Eu is 0.73 ~ 1.0 1, with an average value of 0.84, and most of them show weak losses of EU. The total amount of rare earth elements in ore-bearing tonalite is 124.04× 10-6, (La/Yb) n is 7.8 1 and δEu is 0.60. On the distribution pattern diagram of rare earth elements, all samples (including ore-bearing tonalite) are curves inclined to the right. In the process of hydrothermal alteration, rare earth elements well retain the original rock characteristics.

Fig. 4-3-2 SiO _ 2-K2O diagram of ore-bearing tonalite body in Zhusilenghe Khan Cu-Au prospecting area.

(The classification boundary in the figure is in the middle, 1985)

Tonalite has a low strontium content of (106 ~ 272) × 10-6 (Table 4-3-3) and a high yttrium content of (18 ~ 24) × 10-6. On the normalized map of trace elements in the primitive mantle (Figure 4-3-4), it is generally characterized by the enrichment of large ion MagmaElemental (LIL E), in which Ba, Nb, La, Sr, P and Ti are relatively lacking, while Th, K, Ce and Sm are relatively enriched. Among the ore-forming elements, the copper content ranges from (20.6 ~1571) ×10-6, which is obviously higher than the average copper content of crustal granite (20 × 10-6). The lead content ranges from (13.5 ~100) ×10-6, and most samples are larger than the average lead content of granite in the crust (20× 10-6). The content of zinc varies from (44.2 ~ 302) × 10-6, and most samples are higher than the average content of zinc in crustal granite (60 × 10-6). The gold content varies from (0.0005 ~ 0.01)×10-6, and most samples are less than the average gold content of granite in the crust (0.0045 × 10-6). The range of silver content is (0. 15 ~ 6.6) × 10-6, and all the samples are higher than the average silver content of granite in the crust (0.05× 10-6). Due to the alteration and mineralization of rock mass in different degrees, the content of ore-forming elements has changed greatly. It is worth mentioning that the contents of copper, lead, zinc, gold and silver in ore-bearing tonalite are all high, and the zinc content is as high as 24 155× 10-6, that is, 2.4 155%, which has formed a zinc mineralized body. Generally speaking, the content of ore-forming elements in rock mass is high, especially after alteration and mineralization, so that the rock mass itself directly constitutes ore-bearing surrounding rock. In Figure 4-3-5, the ore-bearing tonalite in Zhusileng Harkhan copper-gold prospecting area is mainly located in volcanic arc granite area (VAG). In the R 1-R2 diagram (Figure 4-3-6), the sampling point is located at the junction of Area 6 and Areas 2, 3 and 4, showing the characteristics of syncollision granitoids, and tonalite may be the product of collision orogeny.

Table 4-3-3 Analysis Results of Rare Earth and Trace Elements in Ore-bearing Rock Mass in Zhusileng Harkhan Copper-Gold Exploration Area (wB/ 10-6)

sequential

Figure 4-3-3 Distribution Pattern of Rare Earth Elements in Ore-bearing Rock Mass in Zhusilenghe Khan Copper-Gold Exploration Area

Figure 4-3-4 Spider Diagram of Trace Elements in Ore-bearing Rock Mass in Zhusilenghe Khan Copper-Gold Mine Pre-exploration Area

Figure 4-3-5 Trace Element Discrimination Diagram of Ore-bearing Rock Mass in Zhusilenghe Khan Copper-Gold Prospecting Area

(Pierce et al., 1984)

Considering that the discriminant diagram of trace elements by Pearce et al. (1984) has some limitations in application, Pearce et al. (65438+)

On the La-La/Sm diagram (Figure 4-3-7), it can be seen that the data points of tonalite in the prediction area of Zhusileng River Khan form a diagonal line approximately, and it can be considered that the diagenetic process of tonalite is controlled by partial melting.

Verb (abbreviation of verb) Mineralization characteristics

Geological characteristics of (1) mineralized body

1. Characteristics of mineralization zone in the northern exploration area

A I- 1 orebody: I- 1 orebody occurrence is NW-SE with an inclination of 60. The exposed length of the ore body on the surface is 430m, and the thickness is 3-34m. The distribution pattern of the ore body on the surface is determined by the exploration trenches TC5- 1, TC6- 1, TC1,TC1. The copper content is between 0.34% and 0.69%, and the highest value is 65438+. The gold content is (0.25 ~ 0.56) × 10-6, and the highest value is 1.55 × 10-6. The silver content is (2.8 ~ 4.48) × 10-6, and the highest is 10× 10-6. The copper content tends to increase from the surface layer to the deep layer. The mineralized body is controlled by two boreholes, ZK 980 1 and ZK 140 1, and is layered. The surrounding rock near the upper wall ore body is strongly silicified metamorphic sandstone, and the lower wall is biolimestone. The boundary between the ore body and the surrounding rock is clear.

Figure 4-3-6 Discrimination Diagram of Ore-bearing Rock Structure Environment in Zhusileng Heihan Copper-Gold Exploration Area

(According to Batchelor et al., 1985)

Figure 4-3-7 La-La/Sm Diagram of Ore-bearing Rock Mass in Zhusileng Heihan Copper-Gold Prospecting Area

B I-2 orebody: The occurrence of I-2 orebody is the same as I- 1 orebody, with the exposed length of 150m and the thickness of 2 ~ 8m. The surface orebody is controlled by the exploration trough TC6- 1. The copper content is between 0.29% and 2.75%, the gold content is (0. 1 ~ 0.84) × 10-6, and the highest value is 8.52 × 10-6. The silver content is (1.45 ~ 2.44) × 10-6. The surface shape of the ore body is lentil, and the surrounding rocks are greenstone sandy limestone and calcareous sandstone, which are controlled by the NW-trending secondary fault in the pre-survey area.

C I copper mineralization belt: The copper mineralization belt is NW-SW, with a length of 1.4km, and still tends to extend to the southeast. The width of copper mineralization on the surface is 80m, and the widest point is1.20m. The southern boundary of the mineralization zone is bounded by F2 fault, dipping southwest with an inclination of 60 ~ 70, and the northern boundary is bounded by the stratum contact between Wotuoshan Formation and Xipingshan Formation. The sandstone and limestone of Wotuoshan Formation in the near contact zone are strongly broken and have obvious fault structure characteristics. From west to east, the mineralized zones are feldspathic chronological sandstone, tuffaceous sandstone and tonalite, in which granite porphyry veins are exposed in strata and tonalite. Copper-mineralized veinlets with different strengths are developed in the fractures of different rocks in the mineralization zone, and the pulse width varies from several centimeters to several meters, most of which are between several centimeters. There are two groups of occurrences of mineralized veins, most of which are NE with an inclination of 70 to nearly vertical, and a few are SW with an inclination of 60 ~ 80. Surface copper mineralization is common, mostly in the form of veinlets, with a pulse width of several centimeters to more than ten centimeters, the widest point of 4m, and the copper content of 0.23% ~ 0.43%, with the highest value of 1.87%. The gold content is (0. 1 ~ 0.38) × 10-6, and the highest value is 1.6× 10-6. Two boreholes ZK290 1 and ZK570 1 were constructed in tonalite respectively, showing different degrees of copper mineralization. Some areas are rich in intact ore with copper content of 0. 10% ~ 0.42%, and the relationship between ore body and surrounding rock is gradual transition.

2. South ore belt Ⅱ copper mineralization belt

The mineralized zone is 2.7 kilometers long and several meters to more than ten meters wide. The copper ore body is layered, lentil-shaped and discontinuous. The dip angle varies with the trend of the mineralization zone, with the north-south section inclining eastward and the northwest section inclining northeast, with the dip angle of 50 ~ 70. The copper ore body is 2 ~ 3m thick, with a maximum thickness of 6m, and the copper content is 0.44% ~ 0.7%, with a maximum of 2.3%. The ore-bearing surrounding rocks are metamorphic sandstone and metamorphic siltstone.

(2) Mineral composition

Copper minerals related to diorite porphyrite include chalcopyrite, pyrite, pyrrhotite, sphalerite, galena, arsenopyrite and a small amount of chalcocite (plate ⅸ-6); Gangue minerals include chlorite, epidote, quartz, plagioclase, sericite, carbonate and a small amount of fluorite. The metallic minerals that altered tonalite copper mine include chalcopyrite, pyrite, pyrrhotite, sphalerite, galena and molybdenite. Gangue minerals include plagioclase, potash feldspar, quartz, chlorite, epidote, sericite and a small amount of fluorite. The oxidized minerals of copper on the surface are malachite, chalcopyrite and chalcopyrite. In contrast, the main mineral components of ore in Nanqian area are malachite, pyrite, barite, calcite and timely.

(3) Ore structure and structural characteristics

The ore structures in Beiqian area include semi-isomorphic-heteromorphic crystal structure, solid solution decomposition structure and inclusion structure. In different host rocks, ore structures have different structural types. The diorite porphyrite ore bodies are mainly disseminated and punctate; Star-shaped, sparsely disseminated in granite porphyry; It is veined and sparsely distributed in sandstone and tonalite. In the vein of copper mineralization, the ore structure is punctate and massive, and chalcopyrite is intermittently or continuously distributed in the vein in the form of medium-coarse punctate (or aggregate).

(4) Microstructure and structure of minerals

1. Primary sulfide

A. Chalcopyrite: There are two forms: abnormal-granular structure and solid solution structure. The former coexists with pyrite and sphalerite or is embedded in timely particles; The latter chalcopyrite is wrapped in sphalerite in the form of emulsion droplets. The two structures of chalcopyrite reflect the existence of two stages of copper mineralization The structure is disseminated, sparsely disseminated, spotted and veined;

B. Pyrite: There are two structural forms, one is a directionally fractured autotype-semi-autotype structure, which has little to do with copper mineralization. The other is a special-shaped granular structure, which is related to copper mineralization, mostly associated with chalcopyrite or containing chalcopyrite;

C. sphalerite: self-form to semi-self-form structure, coexisting with chalcopyrite and pyrite or containing chalcopyrite;

D. chalcocite: special-shaped structure, wrapped in chalcopyrite;

E. arsenopyrite: semi-authigenic structure, mostly occurring at the edge of pyrite;

F. Gold minerals: irregular granular structure, occurring in pyrite;

G molybdenite: semi-authigenic-heteromorphic granular structure, occurring in copper-bearing siliceous veinlets, coexisting with chalcopyrite or embedded in timely grains;

Galena: semi-authigenic granular, with the same occurrence characteristics as molybdenite;

1. Pyrrhotite: semi-authigenic granular structure embedded among timely grains;

Fluorite: irregular granular structure, which exists in different types of copper mines.

2. Copper oxide

Malachite: abnormal granular structure, gel-like, disseminated, reticulated vein structure, produced on the surface of various minerals;

B. Black copper ore: porphyry structure, earthy structure, with black circular spots on the surface, mainly appearing on the surfaces of granite porphyry, tonalite and copper vein;

C. Chalcopyrite: soil-like structure, mainly appearing on the surface of granite porphyry and copper mineralization rich body;

D kyanite: veinlet structure, distributed sporadically in 390-point limestone stratum of Line 25.

3. Ore structure and structure in the southern pre-survey area

The ore structure is semi-autogenous-abnormal granular structure; The structures are colloidal, breccia, veinlets and thin films.

(5) Wall rock alteration

The main types of hydrothermal alteration are:

A. Pan Qingyanization: The most extensive hydrothermal alteration covers almost the whole pre-survey area. The local rocks become blue rocks. Altered minerals include epidote, chlorite and carbonate minerals. This alteration is related to the hydrothermal activity of copper mineralization, and the surrounding rocks of copper bodies related to porphyrite generally have strong blue rocks.

B. Silicification: mainly developed in the copper mineralization belt, and the surface mostly appears in the form of silicified veinlets. The porphyrite-related copper body controlled by ZK 140 1 hole has a typical silicification phenomenon in the surrounding rock near the ore body, and the metamorphic sandstone near the ore body is strongly silicified, which has a certain indication for finding copper bodies.

C sericitization and kaolinization: mainly occurring in granite porphyry and its lateral secondary fault structure development area;

D. Pyritization: widely distributed, weak in the north and strong in the south. Pyritization in the northern part of the pre-survey area generally develops in the surrounding rocks, granite porphyries and ore bodies near the mine in a star shape. Pyritization in the south of the pre-survey area is mainly developed in calcareous sandstone and biolimestone strata, and pyrite is star-shaped, thin-film and veinlets.

According to the distribution characteristics of copper mineralization and pyritization, the pre-investigation area can be divided into copper mineralization area, Panqing mineralization area and pyritization area from north to south.

Geophysical characteristics of intransitive verbs

(a) regional geophysical characteristics

On the aeromagnetic anomaly map, this area is a wide and gentle negative magnetic field area, which is mainly caused by the weakly magnetic metamorphic rock series of the Mesoproterozoic Yuanzaoshan Group, and there are elliptical and flaky positive and negative magnetic anomalies in some areas. The δ t value is generally 100nT, which is distributed in the northwest direction. Weak positive magnetic anomalies are related to Hercynian granites and granodiorites which are widely distributed.

The Bouguer gravity anomaly is distributed in the northwest direction, which is a region with relatively high gravity value, and the gravity field value (δ g) ranges from (-150 ~-180) ×10-5m/S2. The field value decreases gradually from north to south, which is consistent with the Moho surface deepening gradually from north to south (49 ~ 53 km). The contour lines of Bouguer gravity anomaly regularly twist or turn in the same direction, which is related to the existence of plate suture zone.

(2) Geophysical characteristics of the pre-survey area

1. Physical properties of rocks and ores

See Table 4-3-4, Table 4-3-5 and Table 4-3-6 for the determination results of physical parameters of representative rock (ore) samples on the surface, shallow wells and boreholes.

Table 4-3-4 Statistical Results of Electrical Parameters of Representative Rocks (Minerals)

Table 4-3-5 Statistical Results of Magnetic Parameters of Representative Rocks (Minerals)

Table 4-3-6 Statistical Results of Physical Parameters of Representative Rocks (Ores)

The physical characteristics of representative rocks (ores) in the pre-survey area are as follows:

A. The physical properties of the main rocks (minerals) on the surface have little difference, but they are obviously different from the deeply weathered primary rocks (minerals), and the difference can reach dozens of times;

B diorite porphyry, granite porphyry and metamorphic fine sandstone containing pyritization and chalcopyrite have obvious physical differences from similar non-mineralized rocks. For example, the surface does not contain pyrite and chalcopyrite diorite porphyry, and the polarizability is between 0.26% and 2.04%, while the borehole core is between 0.74% and 49.91%. The geological bodies that cause high-intensity IP anomalies can only be deep hydrothermal altered rocks (ores), and the corresponding apparent resistivity values all reflect relatively high resistance, ranging from16.0 ~19978 Ω m, and the same is true for the magnetism corresponding to the above IP anomalies. The magnetic variation range of surface rocks (minerals) is (6.5 ~ 96) × 4π× 10-6Si, and that of deep rocks is (84.0 ~1568.2 )× 4π×10-6Si, which is different from other rocks.

C due to the low sulfide content, the apparent polarizability, apparent resistivity and magnetization of sulfide-free rocks are relatively low, and no obvious IP anomalies will occur.

2. IP and magnetic anomalies

The apparent polarizability anomalies found in the pre-survey area are usually related to pyritization and chalcopyrite mineralization, or to ore-bearing veins developed on the surface. The apparent polarizability in the intense pyritization area is relatively high, and the highest value is 14%. In contrast, copper mineralization areas are generally 3% ~ 5%, showing moderate apparent polarizability anomalies. However, no adverse geological factors causing abnormal apparent polarizability were found on the surface or in the borehole.

The apparent resistivity of the prediction area is generally related to the types of rocks and minerals, and the areas with high apparent resistivity are generally the strata with high siliceous content, intermediate-acid intrusive rocks or areas with strong silicification and alteration. Intermediate-acid intrusive rocks, contact zones and fault zones between rock mass and strata can cause high positive magnetic anomalies.

Seven. Geochemical characteristics of prediction area

(1)1:200,000 geochemical anomalies

Abnormal elements such As Cu, As, Sb, Hg, Bi, Zn are a group of elements in low-temperature hydrothermal deposits. The anomalies of these elements show high background characteristics in a large range, while the distribution patterns of abnormal elements show different spatial distribution characteristics. As, Sb and Hg are NW-trending broadband, which is consistent with the NW-trending fault structural line in the prediction area. Copper is a broadband ellipse. The concentration centers of abnormal elements have good consistency. The regional geochemical anomaly of1:200,000 reflects the existence of a geochemical process closely related to fault structures and magmatic hydrothermal activities in this area.

(2)1:50,000 geochemical anomalies

The abnormal element combinations in the northern exploration area are copper, arsenic, antimony, gold, silver, bismuth, tin, molybdenum, zinc and lead. The abnormal element combinations in the southern prediction area are copper, arsenic, antimony, molybdenum, zinc and lead. According to the analysis of element combination characteristics, the prospecting area in the north is characterized by the geochemical activity of intermediate-acid magmatic activity controlled by NW-trending fault structures, while the prospecting area in the south is characterized by the geochemical activity of intermediate-acid magmatic hydrothermal activity controlled by NW-trending and nearly N-S-trending fault structures. Based on the copper enrichment center, six sub-anomalies are divided, among which the northern pre-survey area is located in the sub-anomaly area AS26- 1. From the spatial distribution characteristics of copper anomalies, they are all consistent with arc structures.

(3) Geochemistry of rocks (ores)

1. Geochemistry of rocks (minerals) in the northern exploration area

According to the statistical results in Table 4-3-7, the contents of stone elements in rocks (ores) have the following characteristics: ① The contents of zinc, arsenic, silver, antimony and bismuth are higher in different types of copper ores, especially the highest ones; ② Both mineralized diorite porphyrite and altered diorite porphyrite are characterized by high contents of copper, zinc, arsenic and bismuth; ③ The gold content in granite porphyry is the highest; ④ Different types of copper ores are characterized by high contents of zinc, arsenic and bismuth; ⑤ The contents of copper, zinc, arsenic and bismuth in Pan Qingyan are similar, but the trend of element combination is similar to that of copper ore; ⑥ Molybdenum and tin in high temperature hydrothermal solution are not high in all kinds of rocks and ores. Based on the above-mentioned element content characteristics, the copper deposits, copper mineralized rocks and altered rocks in the prediction area basically have the combination characteristics of zinc, arsenic and bismuth, reflecting that the prediction area was subjected to the geochemical action of the same ore-bearing hydrothermal solution. Compared with the above characteristics, the main mineralized bodies in the pre-survey area are tonalite and diorite porphyry, and the copper mineralization element combination is characterized by the combination of middle zone and outer zone according to the element zoning law of hydrothermal deposits.

2. Element content of borehole ore

As can be seen from the statistics in Table 4-3-8, the element contents of two different types of ores are basically similar. Compared with porphyrite-related ore, altered tonalite-type ore is rich in lead and molybdenum, but relatively lacking in arsenic, antimony, mercury, tin and bismuth, which reflects that there is a certain difference in the formation depth of the two types of ore bodies, that is, the formation depth of diorite-porphyrite-related ore bodies is obviously greater than that of altered tonalite.

Table 4-3-7 Statistical Table of MagmaElemental Content of Surface Rock (Ore)

Table 4-3-8 Characteristic Table of Element Content of Representative Bored Ores

3. Axial zoning characteristics of borehole primary halo

A.ZK980 1 and ZK 140 1 drilling element zoning sequence: gold-lead-mercury-antimony-(tin)-silver (-copper, molybdenum, bismuth)-arsenic-zinc;

B.ZK290 1 and ZK570 1 Drilling element zoning sequence: As-Bi-Au-Sb-Ag-Zn-Hg-Sn-Cu-Mo-Pb;

C.ZK250 1 Drilling element zoning sequence: Bi, Ag, As, Pb, Hg, Cu, Au, Sb, Zn, Mo and Sn.

The overall characteristics of the axial zoning sequence of the above borehole are that the shallow part is rich in gold and leading edge halo elements, while the deep part is rich in copper, and the content of tail halo elements is low, indicating that the ore body has not suffered from strong erosion.

8. Comparative analysis of characteristics with Tuwu copper mine in Xinjiang

The pre-exploration area of Zhusileng Heierhan copper deposit is similar to the Tuwu copper deposit in Xinjiang.

A. Being in the same metallogenic belt in space, the conditions of ore-bearing magmatic rocks are similar, namely diorite porphyry, granite porphyry and tonalite;

B) The metallogenic ages are similar in time and the stratigraphic conditions are similar. The surrounding rocks of Tuwu Copper Mine are Carboniferous clastic rocks and carbonate rocks, while the surrounding rocks of Zhusileng Copper Mine are Devonian clastic rocks and carbonate rocks.

C. The main geochemical elements of ore bodies have similar combinatorial characteristics. Tuwu copper mine is copper, gold, zinc, lead, bismuth, silver, antimony, arsenic, mercury, molybdenum and cobalt, and Zhusileng copper mine is copper, gold, silver, zinc, lead, bismuth, arsenic, antimony, mercury, molybdenum and tin.

D the characteristics of geophysical IP anomalies are similar. The IP anomaly of Tuwu copper mine is generally 2% ~ 8%, with relatively high resistance and magnetism. 2% IP anomaly can be used as drilling basis, and its selection reason is related to the buried depth of the main ore body in Tuwu copper mine below 300m m ... The geophysical IP anomaly in Zhusileng copper mine is 2% ~ 14%, with high resistivity. The IP anomalies in the mineralization zone of Zhusileng copper mine are 2% ~ 6%, and those in the pyritization zone are 4% ~ 14%.

E. The same alteration feature is that green schist is common in * * *, but the difference is that Tuwu copper mine is closely related to silicification and sericitization, and its surface is stronger and wider than that of Zhusileng copper mine, while the distribution of sericitization and silicification in Zhusileng copper mine is limited and relatively weak.

Based on the above comparison characteristics, the pre-exploration area of Zhusileng copper deposit and Tuwu copper deposit are very comparable and belong to the same type of deposit.